CN106040235A - Exhaust gas purification catalyst and method for producing the same - Google Patents
Exhaust gas purification catalyst and method for producing the same Download PDFInfo
- Publication number
- CN106040235A CN106040235A CN201610212807.0A CN201610212807A CN106040235A CN 106040235 A CN106040235 A CN 106040235A CN 201610212807 A CN201610212807 A CN 201610212807A CN 106040235 A CN106040235 A CN 106040235A
- Authority
- CN
- China
- Prior art keywords
- exhaust gas
- gas purifying
- microgranule
- purifying catalyst
- composition metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 174
- 238000004519 manufacturing process Methods 0.000 title claims description 14
- 238000000746 purification Methods 0.000 title abstract description 38
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 89
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 89
- 239000007789 gas Substances 0.000 claims description 154
- 229910052751 metal Inorganic materials 0.000 claims description 134
- 239000004531 microgranule Substances 0.000 claims description 130
- 239000002184 metal Substances 0.000 claims description 125
- 239000000203 mixture Substances 0.000 claims description 116
- 239000012298 atmosphere Substances 0.000 claims description 75
- 239000000428 dust Substances 0.000 claims description 70
- 238000000034 method Methods 0.000 claims description 49
- 239000002912 waste gas Substances 0.000 claims description 44
- 239000003638 chemical reducing agent Substances 0.000 claims description 29
- 239000000243 solution Substances 0.000 claims description 28
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 claims description 24
- 238000007254 oxidation reaction Methods 0.000 claims description 22
- 230000003647 oxidation Effects 0.000 claims description 21
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 14
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 9
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 9
- 239000000843 powder Substances 0.000 claims description 8
- 238000010992 reflux Methods 0.000 claims description 7
- 239000006104 solid solution Substances 0.000 claims description 6
- 229910052593 corundum Inorganic materials 0.000 claims description 5
- 229910001845 yogo sapphire Inorganic materials 0.000 claims description 5
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 claims 3
- 229910052681 coesite Inorganic materials 0.000 claims 2
- 229910052906 cristobalite Inorganic materials 0.000 claims 2
- 239000000377 silicon dioxide Substances 0.000 claims 2
- 229910052682 stishovite Inorganic materials 0.000 claims 2
- 229910052905 tridymite Inorganic materials 0.000 claims 2
- 239000002923 metal particle Substances 0.000 abstract description 22
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 207
- 239000010948 rhodium Substances 0.000 description 185
- 230000000052 comparative effect Effects 0.000 description 60
- 150000002500 ions Chemical class 0.000 description 46
- 238000006722 reduction reaction Methods 0.000 description 41
- 230000009467 reduction Effects 0.000 description 37
- 238000011156 evaluation Methods 0.000 description 23
- 239000000463 material Substances 0.000 description 20
- 238000012360 testing method Methods 0.000 description 20
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 19
- 230000000694 effects Effects 0.000 description 16
- 150000002739 metals Chemical class 0.000 description 13
- 239000004215 Carbon black (E152) Substances 0.000 description 12
- 229930195733 hydrocarbon Natural products 0.000 description 12
- 150000002430 hydrocarbons Chemical class 0.000 description 12
- 239000002245 particle Substances 0.000 description 12
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 11
- 229910002091 carbon monoxide Inorganic materials 0.000 description 11
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 9
- 230000008859 change Effects 0.000 description 9
- 239000003795 chemical substances by application Substances 0.000 description 9
- 239000011259 mixed solution Substances 0.000 description 9
- 239000001301 oxygen Substances 0.000 description 9
- 229910052760 oxygen Inorganic materials 0.000 description 9
- 238000006555 catalytic reaction Methods 0.000 description 8
- 239000003599 detergent Substances 0.000 description 8
- 230000007246 mechanism Effects 0.000 description 8
- 230000001629 suppression Effects 0.000 description 8
- 150000001875 compounds Chemical class 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 229910000420 cerium oxide Inorganic materials 0.000 description 6
- 230000004087 circulation Effects 0.000 description 6
- 238000004140 cleaning Methods 0.000 description 6
- 238000010304 firing Methods 0.000 description 6
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 6
- 239000003223 protective agent Substances 0.000 description 6
- 239000002904 solvent Substances 0.000 description 6
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 5
- 229910052788 barium Inorganic materials 0.000 description 5
- ITHZDDVSAWDQPZ-UHFFFAOYSA-L barium acetate Chemical compound [Ba+2].CC([O-])=O.CC([O-])=O ITHZDDVSAWDQPZ-UHFFFAOYSA-L 0.000 description 5
- 238000009835 boiling Methods 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 5
- 238000001035 drying Methods 0.000 description 5
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 5
- 229910052737 gold Inorganic materials 0.000 description 5
- 239000010931 gold Substances 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 5
- 239000000395 magnesium oxide Substances 0.000 description 5
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 5
- RJIWZDNTCBHXAL-UHFFFAOYSA-N nitroxoline Chemical compound C1=CN=C2C(O)=CC=C([N+]([O-])=O)C2=C1 RJIWZDNTCBHXAL-UHFFFAOYSA-N 0.000 description 5
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 5
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 5
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 5
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 5
- 238000000851 scanning transmission electron micrograph Methods 0.000 description 5
- 229910052814 silicon oxide Inorganic materials 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- VVJKKWFAADXIJK-UHFFFAOYSA-N Allylamine Chemical compound NCC=C VVJKKWFAADXIJK-UHFFFAOYSA-N 0.000 description 4
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 4
- 239000008187 granular material Substances 0.000 description 4
- 239000007791 liquid phase Substances 0.000 description 4
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 229910001928 zirconium oxide Inorganic materials 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- 239000000084 colloidal system Substances 0.000 description 3
- 229910052738 indium Inorganic materials 0.000 description 3
- 238000011068 loading method Methods 0.000 description 3
- 230000033116 oxidation-reduction process Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 150000001299 aldehydes Chemical class 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000005660 chlorination reaction Methods 0.000 description 2
- 238000001246 colloidal dispersion Methods 0.000 description 2
- 239000002274 desiccant Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000005470 impregnation Methods 0.000 description 2
- 238000005342 ion exchange Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 239000007800 oxidant agent Substances 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- SCVFZCLFOSHCOH-UHFFFAOYSA-M potassium acetate Chemical compound [K+].CC([O-])=O SCVFZCLFOSHCOH-UHFFFAOYSA-M 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000003672 processing method Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- SONJTKJMTWTJCT-UHFFFAOYSA-K rhodium(iii) chloride Chemical compound [Cl-].[Cl-].[Cl-].[Rh+3] SONJTKJMTWTJCT-UHFFFAOYSA-K 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 2
- 238000010792 warming Methods 0.000 description 2
- ODIGIKRIUKFKHP-UHFFFAOYSA-N (n-propan-2-yloxycarbonylanilino) acetate Chemical compound CC(C)OC(=O)N(OC(C)=O)C1=CC=CC=C1 ODIGIKRIUKFKHP-UHFFFAOYSA-N 0.000 description 1
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- NOWKCMXCCJGMRR-UHFFFAOYSA-N Aziridine Chemical compound C1CN1 NOWKCMXCCJGMRR-UHFFFAOYSA-N 0.000 description 1
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 1
- AMQJEAYHLZJPGS-UHFFFAOYSA-N N-Pentanol Chemical compound CCCCCO AMQJEAYHLZJPGS-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- 229910002089 NOx Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical class OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 101150003085 Pdcl gene Proteins 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 235000009508 confectionery Nutrition 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 229910017053 inorganic salt Inorganic materials 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000036284 oxygen consumption Effects 0.000 description 1
- HGBOYTHUEUWSSQ-UHFFFAOYSA-N pentanal Chemical compound CCCCC=O HGBOYTHUEUWSSQ-UHFFFAOYSA-N 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 229920000083 poly(allylamine) Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 235000011056 potassium acetate Nutrition 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 230000005476 size effect Effects 0.000 description 1
- 238000000629 steam reforming Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/56—Platinum group metals
- B01J23/63—Platinum group metals with rare earths or actinides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9445—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
- B01D53/945—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific catalyst
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/002—Mixed oxides other than spinels, e.g. perovskite
-
- B01J35/61—
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/01—Engine exhaust gases
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Abstract
The exhaust gas purification catalyst according to the present invention includes fine composite-metal particles containing Rh and Pd, wherein, when the fine composite-metal particles in the exhaust gas purification catalyst are analyzed by STEM-EDX, the average ratio of the amount of Pd with respect to the total amount of Rh and Pd in the fine composite-metal particles is 1.7 atomic % or more and 24.8 atomic % or less.
Description
Technical field
The present invention relates to exhaust gas purifying catalyst and manufacture method thereof.More specifically, the present invention
Relate to exhaust gas purifying catalyst and manufacture method thereof that exhaust-gas purifying performance improves.
Background technology
From internal combustion engine (the such as internal combustion such as petrol engine or Diesel engine for automobile etc.
Machine) in the waste gas discharged containing harmful components, such as carbon monoxide (CO), hydrocarbon (HC)
With nitrogen oxides (NOx) etc..
Therefore, the waste gas being generally provided for decomposing these harmful components of removing in internal combustion engine is clean
Gasifying device, utilizes and is arranged on the exhaust gas purifying catalyst in this waste gas purification apparatus, and these are harmful to
Composition major part is innoxious.As such exhaust gas purifying catalyst, it is known that have such as three
Unit's catalyst and NOxOcclusion reducing catalyst.
Three-way catalyst is to carry out CO under stoichiometric proportion (chemically correct fuel) atmosphere simultaneously
And the oxidation of HC and NOxThe catalyst of reduction.
It addition, NOxOcclusion reducing catalyst is to be oxidized to by the NO in waste gas under dilute atmosphere
NO2And occlusion, and under stoichiometric proportion atmosphere and under dense atmosphere, it is reduced into nitrogen (N2)
Catalyst, make use of dilute atmosphere, stoichiometric proportion atmosphere to become with the waste gas of dense atmosphere dexterously
The change divided.
But, even if in the case of using these catalyst, the purification of waste gas remains problem,
Carry out various research.
The composition metal colloid of patent documentation 1 comprises Determination of multiple metal elements, this composition metal colloid
Mean diameter be 2～12nm, and Determination of multiple metal elements base in the particle of this composition metal
It is evenly distributed on Ben.Specifically, in patent documentation 1, disclose with molar ratio computing with
The composition metal aqueous colloidal dispersion that palladium chloride solution and rhodium chloride solution are mixed by 1:1.
The exhaust gas purifying catalyst that CO or HC of patent documentation 2 purifies has containing Pd
With the alloy of Ag, and this alloy is supported at carrier.
Prior art literature
Patent documentation
Patent documentation 1: JP 2002-102679 publication
Patent documentation 2: JP 2011-78857 publication
Summary of the invention
Invent problem to be solved
It is an object of the invention to, it is provided that a kind of exhaust gas purifying catalyst for waste gas purification,
The composition metal microgranule wherein contained, and manufacture method.
For solving the means of problem
The inventors discovered that, by the following means, it is possible to resolve above-mentioned problem.
＜ 1 ＞ exhaust gas purifying catalyst, it is to have the composition metal microgranule containing Rh and Pd
Exhaust gas purifying catalyst, wherein,
Utilizing STEM-EDX, the microgranule in above-mentioned exhaust gas purifying catalyst is analyzed
Time, the average proportions of the Pd total relative to Rh and Pd is that 1.7 more than atom % 24.8 are former
Sub-below %,
Above-mentioned average proportions is by value calculated as below: random from exhaust gas purifying catalyst
Select the microgranule of more than 10, utilize STEM-EDX to measure respectively selected whole micro-
Grain, selects whole above-mentioned containing Rh and Pd from selected whole microgranules further
Composition metal microgranule, amounts to the Pd of the above-mentioned each composition metal microgranule conjunction relative to Rh and Pd
The ratio of meter, by this total divided by total number of selected whole above-mentioned composition metal microgranule.
Exhaust gas purifying catalyst described in ＜ 2 ＞ ＜ 1 ＞ item, it has dust carrier further,
And above-mentioned composition metal microgranule is supported at above-mentioned dust carrier.
Exhaust gas purifying catalyst described in ＜ 3 ＞ ＜ 2 ＞ item, wherein, above-mentioned dust carrier is
Selected from SiO2、MgO、ZrO2、CeO2、Al2O3、TiO2, they solid solution and
The dust carrier of combinations thereof.
Exhaust gas purifying catalyst described in ＜ 4 ＞ ＜ 2 ＞ or ＜ 3 ＞ item, wherein, relative to upper
Stating the quality of dust carrier, above-mentioned dust carrier is to contain more than below 0 mass % and 40 mass %
There is CeO2。
＜ 5 ＞ exhaust gas purifying method, wherein, makes containing HC, CO under stoichiometric proportion atmosphere
And NOxWaste gas connect with the exhaust gas purifying catalyst described in any one of ＜ 1 ＞～＜ 4 ＞ item
Touch, thus by HC and CO oxidation and by NOxThe most originally purified.
＜ 6 ＞ exhaust gas purifying method, wherein, makes containing NO under dilute atmospherexWaste gas and ＜ 1 ＞～
Exhaust gas purifying catalyst described in any one contact of ＜ 4 ＞ item, by above-mentioned under dense atmosphere
NOxThe most originally purified.
The manufacture method of ＜ 7 ＞ exhaust gas purifying catalyst, it is for including containing Rh ion, Pd
Ion, reducing agent and protectant solution are heated to reflux, and thus generate composition metal microgranule
The manufacture method of exhaust gas purifying catalyst, wherein,
The mol ratio of above-mentioned Rh ion and above-mentioned Pd ion is 70:30～99:1.
The method that ＜ 8 ＞ ＜ 7 ＞ item is recorded, it includes above-mentioned composition metal microgranule is supported at powder
End carrier.
Method described in ＜ 9 ＞ ＜ 8 ＞ item, wherein, above-mentioned dust carrier is selected from SiO2、
MgO、ZrO2、CeO2、Al2O3、TiO2, their solid solution and combinations thereof
Dust carrier.
Method described in ＜ 10 ＞ ＜ 8 ＞ or ＜ 9 ＞ item, wherein, carries relative to above-mentioned powder
The quality of body, above-mentioned dust carrier is with more than containing CeO below 0 mass % and 40 mass %2。
Invention effect
In accordance with the invention it is possible to provide a kind of exhaust gas purifying catalyst for waste gas purification, spy
It not the composition metal microgranule wherein contained, and manufacture method.
Accompanying drawing explanation
Fig. 1 (a) is the scanning transmission type electronic display utilizing band energy dispersion-type X-ray analytical equipment
The STEM of the exhaust gas purifying catalyst of the embodiment 1 that micro mirror (STEM-EDX) is analyzed
Image, Fig. 1 (b) is to illustrate 10 extracted at random from the exhaust gas purifying catalyst of embodiment 1
The figure of the ratio (atom %) of the Pd of each microgranule total relative to Rh and Pd in individual microgranule.
Fig. 2 (a) is the waste gas purification catalysis of the embodiment 2 utilizing STEM-EDX to be analyzed
The STEM image of agent, Fig. 2 (b) be illustrate from the exhaust gas purifying catalyst of embodiment 2 random
In 10 microgranules extracted, the ratio of the Pd of each microgranule total relative to Rh and Pd is (former
Sub-%) figure.
Fig. 3 (a) is the waste gas purification catalysis of the embodiment 3 utilizing STEM-EDX to be analyzed
The STEM image of agent, Fig. 3 (b) be illustrate from the exhaust gas purifying catalyst of embodiment 3 random
In 10 microgranules extracted, the ratio of the Pd of each microgranule total relative to Rh and Pd is (former
Sub-%) figure.
Fig. 4 (a) is the waste gas purification catalysis of the comparative example 1 utilizing STEM-EDX to be analyzed
The STEM image of agent, Fig. 4 (b) be illustrate from the exhaust gas purifying catalyst of comparative example 1 random
In 10 microgranules extracted, the ratio of the Pd of each microgranule total relative to Rh and Pd is (former
Sub-%) figure.
Fig. 5 (a) is the waste gas purification catalysis of the comparative example 3 utilizing STEM-EDX to be analyzed
The STEM image of agent, Fig. 5 (b) be illustrate from the exhaust gas purifying catalyst of comparative example 3 random
In 10 microgranules extracted, the ratio of the Pd of each microgranule total relative to Rh and Pd is (former
Sub-%) figure.
Fig. 6 is the appreciation condition about three-way catalyst, it is shown that time (minute) and temperature (DEG C)
The figure of relation.
Fig. 7 is to illustrate embodiment 1～3 and the work of exhaust gas purifying catalyst of comparative example 1～3
Temperature (DEG C) when property is evaluated and NOxThe figure of the relation of purifying rate (%).
Fig. 8 is to illustrate embodiment 1～3 and the Pd phase of exhaust gas purifying catalyst of comparative example 1
Average proportions (atom %) and NO for the total of Rh and Pdx50% purification temperature (DEG C)
The figure of relation.
Fig. 9 be illustrate to embodiment 1～3 and comparative example 1～3 exhaust gas purifying catalyst with
NOxThe figure of the relation of 50% purification temperature (DEG C).
Figure 10 be illustrate by embodiment 1～3 and the carrier of comparative example 1 be replaced as Al respectively2O3
-ZrO2-TiO2, and with the addition of embodiment 1 '～3 ' and the comparative example 1 ' of Barium acetate wherein
Time (second) when being exposed to dilute atmosphere and dense atmosphere of the sample of exhaust gas purifying catalyst and NOx
The figure of the relation of output (ppm).
Figure 11 is the enlarged drawing being amplified of the part about Figure 10.
Figure 12 is to be shown in as NOxIn performance evaluation B of occlusion reducing catalyst, by dilute
Atmosphere and dense atmosphere are constituted, NOxThe schematic diagram of 1 cyclic part of occlusion reduction circulation.
Figure 13 is about embodiment 4～11 (●) and the waste gas purification of comparative example 4～11 (■)
The sample of catalyst, it is shown that the CeO in dust carrier2Content (quality %) and NOxDischarge
Amount/NOxThe figure of the relation of hold-up (a.u.).
Figure 14 is about embodiment 4～11 (●) and the waste gas purification of comparative example 4～11 (■)
The sample of catalyst, it is shown that the CeO in dust carrier2Content (quality %) and NOxPurify
The figure of the relation of rate (%).
Figure 15 is about based on heating reduction (TPR:Temperature Programmed
Reduction) appreciation condition of method, it is shown that the figure of the relation of time and temperature.
Figure 16 is to illustrate that the waste gas to embodiment 6 ' (solid line) and comparative example 6 ' (dotted line) is clean
Change catalyst sample application heating reduction method time temperature (DEG C) and H2Consumption (TCD
Signal) figure of relation of (a.u.).
Detailed description of the invention
Hereinafter, embodiments of the present invention are described in detail.Being explained, the present invention is not
It is limited to following embodiment, various deformation can be carried out in the range of idea of the invention and come real
Execute.
" exhaust gas purifying catalyst "
The exhaust gas purifying catalyst of the present invention has the composition metal microgranule containing Rh and Pd, and
And when utilizing STEM-EDX that the microgranule in exhaust gas purifying catalyst is analyzed, Pd
The average proportions of the total relative to Rh and Pd is 1.7 more than atom % 24.8 atom below %.
About conventional exhaust gas purifying catalyst, make platinum family element (such as platinum (Pt), rhodium (Rh)
With palladium (Pd) etc.) it is supported at porous oxide carrier (such as aluminium oxide (Al2O3) etc.)
Catalyst be widely known.
Wherein, about Rh, NOxReducing power high, as constituting exhaust gas purifying catalyst
Catalyst metals and thought highly of.
But, Rh is easily oxidised, its NOxReducing power likely declines because of this oxidation.
Accordingly, it is considered to the oxidation of Rh, make the Rh containing excess quantity in exhaust gas purifying catalyst.But
It is, owing to Rh is the rare metal of very high price, therefore from the viewpoint of economy and environment,
It is excessively used is undesirable.
Therefore, the present inventor is conceived to the Pd more weak with the affinity of oxygen and has carried out attentively grinding
Studying carefully, result have developed the average of containing Rh and Pd and the Pd total relative to Rh and Pd
Ratio becomes the composition metal microgranule of 1.7 more than atom % 24.8 atom below %.
In this composition metal microgranule, due to the oxidation of Pd suppression Rh, therefore can be for a long time
Maintain the metallic state of Rh.Therefore, even if under the environmental condition that conventional Rh is easily oxidised,
Such as under conditions of gas composition, pressure and temperature etc., it is possible to maintain or improve urging of Rh
Change activity, and use Rh with applicable amount.
The present inventors have additionally discovered that, owing to Pd self also has high exhaust gas purifying ability, therefore
As result, the composition metal microgranule containing Rh and Pd can be sent out due to both metallic elements
Wave collaborative waste gas purification effect.
The exhaust gas purifying catalyst of the present invention the most optionally has dust carrier, and is combined
Metal particle is supported at dust carrier.
In the case of composition metal microgranule is supported at this dust carrier, due to dust carrier
Specific surface area is big, therefore can increase the contact surface of waste gas and composition metal microgranule.Thus, can make
The performance of exhaust gas purifying catalyst improves.
＜ composition metal microgranule ＞
Composition metal microgranule contains Rh and Pd.
In the case of the particle diameter of composition metal microgranule is the least, specific surface area increase thus Rh
NOxActive site quantity and the NO of PdxActive site increasing number, it is possible to can improve useless
The NO of gas cleaning catalystxReducing power.
It addition, in the case of the particle diameter appropriateness of composition metal microgranule is big, it is possible to can be abundant
Ground plays the NO of exhaust gas purifying catalystxDetergent power.
Accordingly, as the mean diameter of multiple composition metal microgranules, without particular limitation of, but can lift
Go out the mean diameter more than 0nm, more than 1nm or more than 2nm.It addition, as multiple multiple
Close the mean diameter of metal particle, without particular limitation of, but below 100nm, 70nm can be enumerated
Below, below 40nm, below 10nm, below 7nm, 5nm, 4nm or below 3nm
Mean diameter.
Specifically, as the particle diameter of composition metal microgranule, preferably 1nm～10nm scope
Particle diameter, the particle diameter of more preferably 2nm～5nm scope, further preferred 2nm～3nm scope
Particle diameter.
There is the composition metal microgranule of such particle diameter as catalyst component by use, can be real
The composition metal microgranule that existing Rh and Pd coexists with nanometer level, thus can play and be brought by Pd
Suppression Rh oxidation effect.Accordingly, it is capable to access NOxThe waste gas that purifying property improves
Cleaning catalyst.
Being explained, unless otherwise indicated, in the present invention, " mean diameter " refers to using
The equipment more than 10 particles to randomly choosing such as scanning transmission electron microscope (STEM)
The arithmetic mean of instantaneous value of their measured value when equivalent circle diameter (Heywood diameter) is measured.
Sufficiently large in the average proportions of the Pd of the composition metal microgranule total relative to Rh and Pd
In the case of, become prone to play the effect of the suppression Rh oxidation brought by Pd.It addition,
In the case of this ratio is the most excessive, the NO of Rh can be substantially ensured thatxThe quantity of active site.
Particularly as the Pd of the multiple composition metal microgranules total relative to Rh and Pd
Average proportions, can enumerate 1.7 more than atom %, 2 more than atom %, 3 more than atom %, 4
More than atom % and 5 more than atom %, and/or 24.8 below atom %, 20 below atom %,
15 below atom %, 13 below atom %, 10 below atom %, 8 below atom % and 6 are former
The average proportions of sub-below %.
It addition, " the ratio of the total relative to Rh and Pd of the Pd in multiple composition metal microgranules
Example flat close to the total relative to Rh and Pd of the Pd in multiple composition metal microgranules respectively
All ratios " refer to there is answering of many ratios with the Pd close with the average proportions of this Pd
Close metal particle.Such as, the average proportions at this Pd is to play the waste gas of the present invention significantly
In the case of the such ratio of action effect of cleaning catalyst, " there is many to have and this Pd
The composition metal microgranule of ratio of the close Pd of average proportions " mean to make that the present invention's is useless
The action effect of gas cleaning catalyst improves further.
Related to this, as in terms of number benchmark 70%, 75%, 80%, 85%, 90% or
The ratio of the Pd of the composition metal microgranule of more than 95% total relative to Rh and Pd, the most special
Do not limit, but the total relative to Rh and Pd of the Pd in multiple composition metal microgranule can be enumerated
More than the 20% of average proportions, more than 30%, more than 40% and more than 50%, and 190%
Below, the average proportions of less than 180%, less than 170% and less than 160%.
Thus, can be for NOxPurify and maintain enough Rh active site quantity while,
Effectively play the effect of the suppression Rh oxidation brought by Pd.Therefore, available NOxAlso
The exhaust gas purifying catalyst that proper energy power significantly improves.
Be explained, it should be apparent that make Pd in multiple composition metal microgranule relative to Rh and
The ratio of the total of Pd each deliberately away from the Pd in multiple composition metal microgranules relative to Rh
With the average proportions of the total of Pd (such as, the Pd in multiple composition metal microgranules relative to
Less than the 1% of the average proportions of the total of Rh and Pd, or 400% with first-class) be typically to hold
Easy.
Being explained, in the present invention, " ratio of the Pd total relative to Rh and Pd " is
Refer to that the Pd atomic number contained in composition metal microgranule is relative to Rh atom and the total of Pd atom
The ratio of atomic number." ratio of the Pd total relative to Rh and Pd " in the present invention such as
It is to count by using the optical meanss such as STEM-EDX that composition metal microgranule is analyzed
The value calculated.It addition, in the present invention, " the average specific of the Pd total relative to Rh and Pd
Example " refer to by value calculated as below: from exhaust gas purifying catalyst, randomly choose such as 10
Individual above, more than 100 or the microgranule of more than 1000, utilize STEM-EDX decile
Not Ce Ding selected by whole microgranules, select all from selected whole microgranules further
The composition metal microgranule containing Rh and Pd, amount to the Pd of each composition metal microgranule relative to
The ratio of the total of Rh and Pd, by this total divided by selected whole composition metal microgranules
Total number.
It addition, unless otherwise indicated, in the present invention, the ratio of " number benchmark " refers to waste gas
The number of the composition metal microgranule of the specific composition of cleaning catalyst is micro-relative to whole composition metals
The ratio of the number of grain.The composition metal microgranule of the exhaust gas purifying catalyst of the present invention has excellence
Exhaust gas purifying ability.It is understood, therefore, that in terms of number benchmark at least 70% with
On composition metal microgranule have and preferably constitute in the case of, the exhaust gas purifying catalyst of the present invention
It is scaled its every specific mass, specific volume or specific surface area, further amounts of waste gas can be purified.
＜ dust carrier ＞
The composition metal microgranule of the present invention is capable of loading and carrying in dust carrier.
Hold the dust carrier of composition metal microgranule without particular limitation of, can be to urge at waste gas purification
The technical field of agent is typically used as any metal-oxide of dust carrier.
As such dust carrier, such as, can enumerate silicon oxide (SiO2), magnesium oxide (MgO),
Zirconium oxide (ZrO2), cerium oxide (CeO2), aluminium oxide (Al2O3), titanium oxide (TiO2)
And solid solution or combinations thereof etc..
Acid carrier (such as SiO2) and reduction NOxThe compatibility of catalyst metals good.Alkali
Property carrier (such as MgO) with occlusion NOxThe compatibility of K or Ba good.ZrO2At it
There is can suppress under the such high temperature of sintering the sintering of this other dust carrier in its dust carrier, and
And by combining with the Rh as catalyst metals, Steam Reforming reaction occurs thus generates
H2, NO can be carried out efficientlyxReduction.CeO2There is under dilute atmosphere occlusion oxygen, dense
OSC (the Oxygen Storage Capacity) characteristic of oxygen is released under atmosphere, therefore can be by it
It is used in suitably among three-way catalyst etc..Acidity of Aikalinity pharmalyte (such as Al2O3) due to
There is high specific surface area, therefore can use it for carrying out NO efficientlyxOcclusion and reduction.
TiO2The effect of the sulfur poisoning of suppression catalyst metals can be played.
It will be appreciated that according to the characteristic of above-mentioned dust carrier, the waste gas purification catalysis of the present invention
The exhaust gas purifying ability of agent, particularly NOxDetergent power is possibly based on selected powder and carries
The kind of body, form, combine and ratio and/or amount and improve.
＜ Rh microgranule, CeO2And NOxRelation ＞ of occlusion reduction mechanism
(NOxOcclusion reduction mechanism)
As it has been described above, NOxOcclusion reduction mechanism is following mechanism: by waste gas under dilute atmosphere
NO be oxidized to NO2And occlusion, by this NO under stoichiometric proportion atmosphere and dense atmosphere2
It is reduced into nitrogen (N2)。
(at NOxOcclusion reduction mechanism uses Rh and NO during Rh microgranulexBehavior)
As it has been described above, Rh is easy to reduction NOxMetal, on the other hand, be also easier to
Oxidized metal.Under dilute atmosphere under dilute atmosphere of particularly low temperature, Rh microgranule is major part
Oxidized state.When this Rh oxide fine particle is exposed under dense atmosphere, Rh oxide
Microgranule is reduced into Rh metal particle, thus it is believed that present the NO of RhxReducing power.
That is, in order to make Rh present NOxReducing power, Rh needs to be metal particle rather than its oxidation
The state of thing microgranule.
(at NOxOcclusion reduction mechanism uses CeO2Time CeO2And NOxBehavior)
CeO2Also have in addition to above-mentioned OSC characteristic and be prone to adsorb NO2Characteristic.Cause
This, CeO2Occlusion and the NO of oxygen is carried out under dilute atmosphere2Absorption, under dense atmosphere release
Oxygen and NO2.It is explained, CeO2It is prone to adsorb NO2Reason be regarded as due to CeO2
With Al2O3It is in a ratio of alkalescence.
The inventors discovered that, CeO under dense atmosphere2The suppression reduction of Rh oxide thus NOx
Reduction insufficient, accordingly, with respect to NOxOcclusion reduction mechanism, Rh and CeO2Specific group
Close improper.
It is thus possible, for instance comprising Rh microgranule and CeO2Exhaust gas purifying catalyst in, about
NOxOcclusion reduction mechanism, due to the NO can not being occluded under dilute atmosphere under dense atmospherex
Reduce fully, therefore a large amount of NOxIt is discharged to outside, the most likely observes high
NOxSpike (spike).It is explained, " NOxSpike " refer to cut to dense atmosphere from dilute atmosphere
When changing, NOxThe phenomenon that increases of moment output.
Related to this, present inventor has performed wholwe-hearted research, find to comprise containing Rh in employing
With the composition metal microgranule of Pd and as the CeO of dust carrier2Exhaust gas purifying catalyst
In the case of, the generation of this problem can be suppressed.
Do not limited by any principle, but this be regarded as due in above-mentioned composition metal microgranule,
Owing to Pd can suppress the oxidation of Rh, therefore under dense atmosphere particularly under the dense atmosphere of low temperature,
Rh oxide is prone to be reduced into Rh metal.
Therefore, the exhaust gas purifying catalyst in the present invention comprise above-mentioned composition metal microgranule and
Containing CeO2Dust carrier in the case of, NO can be improved under dilute atmospherexAdsorbance,
Under dense atmosphere, under the dense atmosphere of low temperature, particularly improve the catalysis activity of Rh simultaneously.Therefore,
Exhaust gas purifying catalyst in the present invention contains the CeO as dust carrier2In the case of, can
Improve waste gas especially with NOxThe detergent power of waste gas.
Especially, in the catalyst for purification of exhaust gas of the present invention, above-mentioned dust carrier is relative to powder
The quality of end carrier is preferably with more than containing CeO below 0 mass % and 40 mass %2。
At dust carrier relative to the quality of dust carrier with larger proportion, such as with more than 0 matter
Amount % contains CeO2In the case of, above-mentioned NO can be improvedxAbsorbability.Therefore, powder
The CeO that carrier contains2Amount relative to the quality of dust carrier can be more than 0 mass %, 5
More than quality %, more than 10 mass %, more than 15 mass %, more than 20 mass % or 24 matter
Amount more than %.
At dust carrier relative to the quality of dust carrier with small percentage, such as with 40 mass %
Hereinafter contain CeO2In the case of, can be adequately suppressed by CeO2The oxidation of the Rh caused,
And/or by under dense atmosphere from CeO2Reducing agent (the such as reduction such as hydrocarbon that the oxygen of middle releasing causes
Agent) consumption.Therefore, the CeO that dust carrier contains2Amount relative to the matter of dust carrier
Amount can be below below below 40 mass %, 35 mass % or 29 mass %.
The loading amount of the composition metal microgranule that dust carrier holds without particular limitation of, but the most relative
More than dust carrier 100 mass parts, typically 0.01 mass parts, 0.05 mass parts with
Loading amount more than upper, 0.1 mass parts, more than 0.5 mass parts or more than 1 mass parts, and/
Can be maybe below below below 5 mass parts, 3 mass parts or 1 mass parts.
〈NOxOcclusion material ＞
The exhaust gas purifying catalyst of the present invention optionally contains NOxOcclusion material.
NOxOcclusion material without particular limitation of, but can be basic matterial.As NOxOcclusion material
Material, can enumerate: alkali metal and salt thereof, such as potassium (K) and potassium acetate etc.；Alkaline-earth metal and
Its salt, such as barium (Ba) and Barium acetate etc.；And combinations thereof.
" exhaust gas purifying method "
By waste gas purification the method comprise the steps that make under stoichiometric proportion atmosphere containing HC,
CO and NOxWaste gas contact with the exhaust gas purifying catalyst of the present invention, thus by HC and CO
Aoxidize and by NOxOxidation purifies.
Preferably the method for the present invention is applied under stoichiometric proportion atmosphere the internal combustion engine of operating.
Under stoichiometric proportion atmosphere, HC and CO as reducing agent and the NO as oxidantx
React with theoretical equivalence ratio, H can be converted into2O、CO2And N2。
Make the side that waste gas contacts under stoichiometric proportion atmosphere with the exhaust gas purifying catalyst of the present invention
Method can be optional method.
It addition, the method comprise the steps that of waste gas purification is made containing NO under dilute atmospherex's
Waste gas contacts with the exhaust gas purifying catalyst of the invention described above, by this NO under dense atmospherexReduction
Purify.
Preferably the method for the present invention is applied under dilute atmosphere the internal combustion engine of operating.This is because
Under dilute atmosphere, it is easy to by HC and CO oxidation and removing, on the other hand, be difficult to NOx
Reduction and removing, thus produce substantial amounts of NOx。
Make containing NO as under dilute atmospherexThe exhaust gas purifying catalyst of waste gas and the present invention connect
The method touched, can use optional method.
" manufacture method of exhaust gas purifying catalyst "
Make the method comprise the steps that containing Rh ion, Pd of exhaust gas purifying catalyst
Ion, reducing agent and protectant solution are heated to reflux, and thus generate composition metal microgranule
Operation；Wherein, the mol ratio of above-mentioned Rh ion and above-mentioned Pd ion is 70:30～99:1.
Generally, the metal particle of nano-scale has different from block due to quantum size effect
Electronic energy structure, thus demonstrate the electro-optical characteristic depending on particle size.And then,
For the metal particle of the biggest nano-scale of specific surface area, expect as highly active catalysis
Agent plays a role.
About the manufacture method of the metal particle of such nano-scale, following chemical reduction method
It is known that add the reducing agents such as alcohol in comprising the mixed solution of salt of each metallic element, and
As required while this mixed solution is carried out heating etc., each by what mixed solution comprised
The ion of metallic element reduces simultaneously.
But, in the case of making different metal ion chemistry reduction, generally, oxidoreduction
The ion of the metallic element that current potential is high is first reduced.Therefore, oxidation-reduction potential is sometimes generated high
Metallic element be present in the low metallic element of the middle section of microgranule, oxidation-reduction potential and exist
Composition metal microgranule in the so-called nucleocapsid structure of composition metal microgranule about.
Owing to, in the composition metal microgranule of this nucleocapsid structure, element is not evenly distributed, because of
This, it is possible to the ability of catalyst can not be played fully.
It is thus possible, for instance patent document 1 discloses that to by palladium chloride solution with rhodium chloride solution to rub
The composition metal aqueous colloidal dispersion irradiating laser bundle that you mix with 1:1 than meter, so that compound
The method being evenly distributed of the element in metal colloid particle.
In contrast to this, in the method for the invention, laser etc. is not used.Therefore, it can with
Less process number generates containing Rh and Pd and Elemental redistribution uniform composition metal microgranule.
Therefore, it is possible to provide the manufacture method of economic and eco-friendly exhaust gas purifying catalyst.
Do not limited by any principle institute, but it is believed that laser etc. can not be used and generate from liquid phase
Reason containing Rh and Pd and Elemental redistribution uniform composition metal microgranule is, the oxygen of Rh
The oxidation-reduction potential (0.99V) changing reduction potential (0.758V) and Pd is close value,
There is the reduction of each metal ion the most at substantially the same time.
Heat as to containing Rh ion, Pd ion, reducing agent and protectant solution
Backflow time, without particular limitation of, but can enumerate more than 0.5 hour, more than 1 hour, 1.5
More than hour and more than 3 hours, and/or 48 hours below, less than 24 hours, 12 hours with
The lower time with less than 6 hours.
It addition, the method for the present invention can optionally farther include to carry out generating to be combined
During the operation of metal particle or after this operation, composition metal microgranule is supported at dust carrier
Operation.
Order and method that composition metal microgranule is supported at dust carrier can be arbitrary order
And method.Order and method that composition metal microgranule is supported at dust carrier can be such as such as
Under order and method: to containing Rh ion, Pd ion, reducing agent and protectant molten
After liquid is heated to reflux, this solution adds dust carrier and stirs, thus by compound gold
Belong to microgranule and be supported at dust carrier.Thus, composition metal microgranule can be supported at powder efficiently
Carrier.
＜ Rh ion and Pd ion ＞
Rh ion and Pd ion is contained containing reducing agent and protectant solution.
As the raw material of Rh ion, without particular limitation of, but such as can enumerate salt and the Rh of Rh
Halogenide etc., and combinations thereof.As the raw material of Rh ion, can enumerate: Rh's
Inorganic salt, such as nitrate, phosphate and sulfate etc.；The acylate of Rh, such as oxalic acid
Salt and acetate etc.；The halogenide of Rh, such as fluoride, chloride, bromide and iodide
Deng；And combinations thereof.
About the raw material of Pd ion, can refer to the record of the raw material of above-mentioned Rh ion.
The concentration of Rh ion and Pd ion without particular limitation of.As Rh ion and Pd ion
Concentration, preferably their total ion concentration is in the range of 0.01M～0.20M.
As Rh ion and the mol ratio of Pd ion, without particular limitation of, but can with as mesh
The mol ratio of Rh with Pd in target composition metal microgranule is relevant, such as can enumerate 70:30～
The mol ratio of 99:1, the mol ratio of 75:25～95:5 and the mol ratio of 80:20～90:10.
As long as the mol ratio of Rh ion and Pd ion can manufacture the waste gas purification of the above-mentioned present invention
The composition metal microgranule of catalyst just without particular limitation of.Their mol ratio can be sent out with above-mentioned
The Pd of the composition metal microgranule of the bright exhaust gas purifying catalyst total relative to Rh and Pd
Average proportions is correlated with.In such a case it is possible to consider also archeus (the such as oxygen of these ions
Change reduction potential or the solid solution easness of each element) determine their mol ratio.
＜ reducing agent ＞
Reducing agent is contained containing Rh ion, Pd ion and protectant solution.
Reducing agent can be used for reducing Rh ion and Pd ion thus generate composition metal microgranule.
It addition, reducing agent can also optionally have the effect as solvent.
As reducing agent, without particular limitation of, but the most in normal conditions, there are such as 95 DEG C
The reducing agent of the boiling point of above, more than 100 DEG C, more than 110 DEG C or more than 120 DEG C.
Owing to reducing agent has above-mentioned boiling point, therefore can effectively reduce Rh ion and Pd from
Son, and the Elemental redistribution uniform composition metal microgranule that Rh and Pd can be generated.Therefore, make
For to being heated to reflux containing Rh ion, Pd ion, reducing agent and protectant solution
Temperature, the temperature more than boiling point of the most above-mentioned reducing agent.
As reducing agent, without particular limitation of, but can enumerate alcohol, sweet alcohols and aldehydes etc. and they
Combination.As reducing agent, alcohol, such as propanol, butanol and amylalcohol etc. can be enumerated；Glycol, example
Such as ethylene glycol etc.；Aldehyde, such as valeral etc.；And combinations thereof.
As the amount of reducing agent, without particular limitation of, but the total mole relative to Rh and Pd,
The mole of 1 times～100000 times scope, the mole of 1 times～50000 times scope can be enumerated
Mole with 1 times～10000 times scope.
＜ protective agent ＞
Solution containing Rh ion, Pd ion and reducing agent contains protective agent.
Protective agent can prevent the excessive gathering each other of composition metal microgranule, and makes composition metal microgranule
Appropriateness dispersion in the solution.Therefore, protective agent can make the multiple multiple of substantially uniform nano-scale
Close metal particle appropriateness dispersion in exhaust gas catalyst.
As protective agent, without particular limitation of, but can enumerate: polyvinylpyrrolidone (PVP),
Polyvinylpyrrolidone K25 (PVP-K25), polymine, polyallylamine, poly-(N-
Carboxymethyl) allylamine, poly-(N, N-bis-carboxymethyl) allylamine and poly-(N-carboxymethyl) aziridine etc.
And combinations thereof.Wherein, from the viewpoint of dissolubility height, preferably PVP.
As protectant concentration, as long as can prevent metal particle gathering each other from limiting the most especially
Fixed, but such as total mole relative to Rh and Pd, can enumerate: 1 times～1000 times of models
Mole, the mole of 1 times～500 times scope and the mole of 1 times～100 times scope enclosed.
Here, in the case of protective agent is the polymer such as PVP, protectant molar concentration refers to it
The mole of monomeric unit.
＜ solvent ＞
Optionally contain containing Rh ion, Pd ion, reducing agent and protectant solution
Solvent.
Solvent without particular limitation of.As the boiling point of solvent, the boiling point of the most above-mentioned reducing agent.
Other ＞ of ＜
About the element of the method for the present invention, can refer to the note of above-mentioned exhaust gas purifying catalyst
Carry.
The present invention is further described with reference to embodiments illustrated below, it will be clear that the present invention
Scope do not limited by these embodiments.
Embodiment
" embodiment 1 (liquid phase reduction) "
＜ comprises the preparation ＞ of the mixed solution of catalyst metals
Measure the 0.078mmol chlorination Pd (PdCl as Pd ion2) and the distillation of 5mL
They are mixed in the beaker of 100mL by water.It addition, measure 1.477mmol as Rh
Chlorination Rh (the RhCl of ion3) and the distilled water of 5mL, by them at the beaker of 100mL
Middle mixing.Solution A is prepared by these Pd solution and Rh solution being mixed.
Measure 3.452g as protectant PVP-K25 and 150mL as the 1-of reducing agent
They are stirred in the separable flask of 500mL by propanol, are dissolved by PVP-K25, by
This prepares solution B.
The 1-propanol of above-mentioned solution A 150mL is washed the 500mL being placed with above-mentioned solution B
Separable flask in, and stir this mixed solution.Then, this mixed solution will be placed with
The separable flask of 500mL immerses the oil bath of 102 DEG C, carries out N2Bubbling, is carried out
It is heated to reflux continuing 1.5 hours.After having carried out being heated to reflux, above-mentioned mixed solution is cooled to
Room temperature.
＜ catalyst metals on the powdery support hold ＞
On the other hand, in the beaker of 500mL, 80g is measured as dust carrier
Al2O3-CeO2-ZrO2.In the beaker of this 500mL, add above-mentioned mixed solution and stir,
Hot bath is utilized to make solvent evaporate.It addition, residue dried one evening that will obtain in drying oven
Afterwards, crushed, persistently burnt till at 500 DEG C 2 hours in firing furnace.
The compacting ＞ of ＜ burned material
From firing furnace, take out burned material and load the sack of CIP (isostatic cool pressing processing method)
In, and be vacuum-packed.With 1 ton/cm2It is suppressed, sieves, and strike with pestle
Beat to granulate.Using this granule as the sample of exhaust gas purifying catalyst.It is explained,
When taking out burned material from firing furnace, in the case of burned material is assembled, it is also possible to use pestle
Broken burned material.
" embodiment 2 and 3 and comparative example 1 and 2 (liquid phase reduction) "
It is explained, in addition to the mole of change Rh and Pd, similarly to Example 1
Operation preparation embodiment 2 and 3 and the sample of exhaust gas purifying catalyst of comparative example 1 and 2.
" comparative example 3 (impregnation method) "
＜ comprises the preparation ＞ of the mixed solution of catalyst metals
Measure the 0.09g nitric acid Pd (8.2 mass %) as Pd ion, and measure 1.57g
Nitric acid Rh (2.75 mass %) as Rh ion.They are exchanged with the ion of 50mL
Water stirs together in the beaker of 100mL, prepares solution C.
＜ catalyst metals on the powdery support hold ＞
On the other hand, the 25g Al as dust carrier is measured2O3-CeO2-ZrO2.By its with
The ion exchange water of 150mL stirs together in the beaker of 500mL, prepares solution D.
While washing altogether with ion exchange water, above-mentioned solution C and solution D are mixed, prepare molten
Liquid E.This solution E evaporation drying is made to become solid.It addition, by this drying solid in drying oven
After drying over night, it is persistently burnt till 2 hours at 500 DEG C at firing furnace.
The compacting ＞ of ＜ burned material
From firing furnace, take out burned material and load the sack of CIP (isostatic cool pressing processing method)
In, and be vacuum-packed.With 1 ton/cm2It is suppressed, sieves, and strike with pestle
Beat to granulate.Using this granule as the sample of exhaust gas purifying catalyst.It is explained,
When taking out burned material from firing furnace, in the case of burned material is assembled, it is also possible to use pestle
Broken burned material.
Table 1 below shows embodiment 1～3 and comparative example 1～3 in the Rh that uses and
The mole of Pd.
[table 1]
It is explained, " the 85:15 in table 1※" represent in the sample of comparative example 3, Rh microgranule
Exist by oneself with Pd microgranule, and contain Rh and Pd with molar ratio computing with 85:15.
＜ STEM-EDX analyzes ＞
Should to the sample of the exhaust gas purifying catalyst of preparation in embodiment 1～3 and comparative example 1～3
With STEM-EDX, thus from its STEM image, extract multiple metal particle as mensuration
Point, evaluates composition and the particle diameter of metal particle at each measuring point.By embodiment 1～3 and compare
The result of example 1 and 3 is shown in Fig. 1～5.It is explained, in the sample of arbitrary example, sample
The mean diameter of product is about 3nm.
From Fig. 1 (a), microgranule exists in exhaust gas purifying catalyst dispersedly.
From Fig. 1 (b), above-mentioned microgranule is the composition metal microgranule containing Rh and Pd.It addition,
From Fig. 1 (b), the Pd in these composition metal microgranules total relative to Rh and Pd
Ratio is in the range of 2 atom %～13.5 atom %.In addition we know, by each compound gold
The ratio belonging to the total relative to Rh and Pd of the Pd in microgranule carries out arithmetic average, Duo Gefu
The average proportions closing the total relative to Rh and Pd of the Pd in metal particle is 7.5 atom %.
Thus, it can be known that the ratio of the total that the Pd in composition metal microgranule is relative to Rh and Pd
The average proportions of the total relative to Rh and Pd of the Pd in multiple above-mentioned composition metal microgranules
27%～180% in the range of.
From Fig. 2 (a), microgranule exists in exhaust gas purifying catalyst dispersedly.
From Fig. 2 (b), above-mentioned microgranule is the composition metal microgranule containing Rh and Pd.It addition,
From Fig. 2 (b), the Pd in these composition metal microgranules total relative to Rh and Pd
Ratio is in the range of 12 atom %～31 atom %.In addition we know, by each compound gold
The ratio belonging to the total relative to Rh and Pd of the Pd in microgranule carries out arithmetic average, Duo Gefu
The average proportions closing the total relative to Rh and Pd of the Pd in metal particle is 16.5 atom %.
Thus, it can be known that the ratio of the total that the Pd in composition metal microgranule is relative to Rh and Pd
The average proportions of the total relative to Rh and Pd of the Pd in multiple above-mentioned composition metal microgranules
72.7%～188% in the range of.
From Fig. 3 (a), microgranule exists in exhaust gas purifying catalyst dispersedly.
From Fig. 3 (b), above-mentioned microgranule is the composition metal microgranule containing Rh and Pd.It addition,
From Fig. 3 (b), the Pd in these composition metal microgranules total relative to Rh and Pd
Ratio is in the range of 5.5 atom %～46.4 atom %.In addition we know, by each compound
The ratio of the total relative to Rh and Pd of the Pd in metal particle carries out arithmetic average, multiple
The average proportions of the total relative to Rh and Pd of the Pd in composition metal microgranule is 24.8 former
Sub-%.
Thus, it can be known that the ratio of the total that the Pd in composition metal microgranule is relative to Rh and Pd
The average proportions of the total relative to Rh and Pd of the Pd in multiple above-mentioned composition metal microgranules
22%～187% in the range of.
As it has been described above, " the ratio of the total relative to Rh and Pd of the Pd in composition metal microgranule
The average specific of the example Pd in the multiple above-mentioned composition metal microgranules total relative to Rh and Pd
In the range of about the 20%～about 190% of example ", in other words, refer to that there is many has and be somebody's turn to do
The composition metal microgranule of the ratio of the Pd that the average proportions of Pd is close.
From Fig. 4 (a), microgranule exists in exhaust gas purifying catalyst dispersedly.By Fig. 4 (b)
Understanding, above-mentioned microgranule is the metal particle containing only Rh.
From Fig. 5 (a), microgranule exists in exhaust gas purifying catalyst dispersedly.By Fig. 5 (b)
Understanding, above-mentioned microgranule is to contain only Rh or contain only the metal particle of Pd.
" the evaluation A of catalyst "
About embodiment 1～3 and the sample of exhaust gas purifying catalyst of comparative example 1～3, evaluate
As the performance of three-way catalyst, and about embodiment 1～3 and the waste gas purification of comparative example 1
The sample of catalyst, evaluates as NOxThe performance of occlusion reducing catalyst.
＜ is as the performance evaluation A ＞ of three-way catalyst
As in performance evaluation A of three-way catalyst, the catalyst of gas flow type is used to comment
Valency device.Specifically, test gas is made to flow by this catalyst test apparatus, by making
The composition of the test gas after contacting is measured with sample with infrared measure (FT-IR).
Being explained, the quality of above-mentioned sample is 3g, the test gas during evaluation of three-way catalyst
Body is to be constituted as follows: NO:0.15%, O2: 0.70%, CO2: 10.00%, CO:0.65%,
C3H6: 0.10%, H2O:3.00%, N2: surplus.
Intensification speed it addition, be 20L/ minute by the flow rate set of test gas, in evaluating
Degree is set as 20 DEG C/min, and is to comment in the range of 100 DEG C～400 DEG C in temperature
Valency.The summary of this condition determination is shown in Fig. 6.
Specifically, the evaluation of three-way catalyst is by being carried out as follows: temperature (DEG C) and NOx
The mensuration of purifying rate (%)；And the average proportions of the total that Pd is relative to Rh and Pd is (former
Sub-%) and NOxThe mensuration of 50% purification temperature (DEG C).Result is shown in Fig. 7 and Tu
8。
(temperature (DEG C) and NOxThe mensuration of purifying rate (%))
Fig. 7 is to illustrate embodiment 1～3 and the work of exhaust gas purifying catalyst of comparative example 1～3
Temperature (DEG C) when property is evaluated and NOxThe figure of the relation of purifying rate (%).By Fig. 7
Understand following (i)～(iii):
I () is at NOxPurifying rate becomes to be about in the range of 0%～about 60%, micro-with only having Rh
The temperature of the sample of the comparative example 1 of grain is compared, and has the composition metal microgranule containing Rh and Pd
The temperature of sample of embodiment 1～3 be lower temperature.Especially, at NOxPurifying rate (%)
Become and be about in the range of 0%～about 95%, compared with the temperature of the sample of comparative example 1, implement
The temperature of the sample of example 1 and 2 is lower temperature；
(ii) at NOxPurifying rate becomes to be about in the range of 5%～95%, and only has Pd microgranule
The temperature of sample of comparative example 2 compare, there is composition metal microgranule containing Rh and Pd
The temperature of the sample of embodiment 1～3 is lower temperature；
(iii) NO of the sample of the comparative example 3 and containing Rh microgranule and Pd microgranulexPurifying rate
Compare, the NO of the sample of the embodiment 1～3 of the composition metal microgranule containing Rh and PdxOnly
Rate is at least higher in the range of about 260 DEG C～400 DEG C.
Therefore, by above-mentioned (i)～(iii) it is understood that to have the composition metal containing Rh and Pd micro-
The NO of the exhaust gas purifying catalyst of grainxPurifying rate with conventional containing Rh microgranule, Pd microgranule or
The NO of the exhaust gas purifying catalyst of person's Rh microgranule and Pd microgranulexPurifying rate is compared higher, for
Higher activity.
This is regarded as, because Pd inhibits the oxidation of Rh, can maintaining the gold of Rh for a long time
Genus state, thus maintains or improves NOxDetergent power.
(average proportions (atom %) of the Pd total relative to Rh and Pd and NOx50%
The mensuration of purification temperature (DEG C))
Fig. 8 is to illustrate embodiment 1～3 and the Pd phase of exhaust gas purifying catalyst of comparative example 1
Average proportions (atom %) and NO for the total of Rh and Pdx50% purification temperature (DEG C)
The figure of relation.As shown in Figure 8, with the sample (Pd:0 of the comparative example 1 containing Rh microgranule
Atom %) compare, there is the embodiment 1～3 of composition metal microgranule containing Rh and Pd
Sample achieves the NO of 50% at lower temperaturesxPurifying rate.
It addition, represent the Pd total relative to Rh and Pd average proportions (atom %) with
NOxThe curve of the relation of 50% purification temperature (DEG C) is downwardly projecting curve.By this Fig. 8
Understand, NOxThere is lower temperature scope compared with the past in 50% purification temperature, i.e. exists useless
The temperature range of gas cleaning catalyst activation.It can therefore be understood that, should in the range of Pd relative to
The average proportions of the total of Rh and Pd is for being suitable for purifying NOxPd relative to Rh and Pd
The average proportions of total.
NO at the sample to the sample of embodiment 1～3 and comparative example 1x50% purification temperature
When comparing, the NO of the sample (Pd:24.8 atom %) of embodiment 3x50% purifies temperature
Degree (294.8 DEG C) is less than the 50%NO of the sample (Pd:0 atom %) of comparative example 1xPurify
Temperature (296.9 DEG C).It addition, from the curve of Fig. 8, at Pd relative to Rh and Pd
The average proportions of total in the case of more than 0 atom % and less than about 27 atom %, NOx
50% purification temperature is less than 296.9 DEG C, and then it is understood that less than 294.8 DEG C of embodiment 3
Within the temperature range of, exist and be best suited for purifying NOxThe Pd total relative to Rh and Pd
Average proportions, according to the curve of Fig. 8, this most suitable average proportions be about 1.7 atom %～
24.8 atom %.
Be explained, as it has been described above, if it is considered that Pd in composition metal microgranule relative to
The ratio of the total of Rh and Pd Pd in multiple above-mentioned composition metal microgranules is relative to Rh
In the range of about the 20%～about 190% of the average proportions of the total of Pd, then it is appreciated that
In the sample of embodiment 1～3, the composition metal that there is the ratio that many has such Pd is micro-
Grain, the ratio of this Pd with for purify NOx(about 1.7 is former for the average proportions of effective Pd
Sub-%～about 24.8 atom %) close.It can therefore be understood that, due in multiple composition metal microgranules
Pd in multiple above-mentioned composition metal microgranules of the ratio of the Pd total relative to Rh and Pd
In the range of about the 20%～about 190% of the average proportions of the total relative to Rh and Pd, because of
The NO of the sample of this embodiment 1～3xDetergent power improves further.
It is explained, table 2 and Fig. 9 shows embodiment 1～3 and comparative example 1～3
Sample and NOxThe relation of 50% purification temperature (DEG C).
[table 2]
It is explained, " the 85:15 in table 2※" represent comparative example 3 sample in Rh microgranule and
Pd microgranule exists by oneself, contains Rh and Pd with molar ratio computing with 85:15.
From table 2 and Fig. 9, with the NO of the sample of comparative example 2 and 3x50% purification temperature
Compare, the NO of the sample of embodiment 1～3x50% purification temperature is low, therefore embodiment 1～3
The NO of samplexDetergent power is higher.
Especially, have employed liquid phase reduction embodiment 2 sample with have employed impregnation method
Comparative example 3 sample in, the mol ratio of Rh with Pd in sample is roughly the same, but implement
The NO of the sample of example 2x50% purification temperature is low more than 35 DEG C.
This is it is believed that be: in the sample of embodiment 2, and the microgranule of catalyst metals contains Rh
And Pd, and Rh and Pd coexist with nanometer level.I.e., it is believed that Pd inhibits Rh's
Oxidation, maintains the metallic state of Rh, and therefore Rh is activated, the sample of embodiment 2
NOx50% purification temperature step-down.
It addition, it can be said that owing to Pd self also has high exhaust gas purifying ability, result contains
The composition metal microgranule having Rh and Pd has played collaborative waste gas due to both metallic elements
Clean-up effect.
＜ is as NOxThe performance evaluation A ＞ of occlusion reducing catalyst
As NOxIn the performance evaluation of occlusion reducing catalyst, employ 32g's
Al2O3-ZrO2-TiO2As dust carrier, and quality based on sample is in terms of 11 mass %
Use Barium acetate as NOxOcclusion material, in addition, have employed the property with three-way catalyst
The embodiment 1 that can use in evaluating～3 and the same sample of the sample of comparative example 1.Hereinafter, will
The sample (3g) of this performance evaluation is referred to as embodiment 1 ', 2 ' and 3 ' and the sample of comparative example 1 '.
It addition, as NOxIn the performance evaluation of occlusion reducing catalyst, employ gas stream
The catalyst test apparatus of formula.Specifically, test gas flowing is made to be commented by this catalyst
Valency device, by using infrared measure (FT-IR) to measure the test after contacting with sample
The composition of gas.
Test gas is made up of dilute atmosphere and dense atmosphere, in this evaluation, the temperature of 450 DEG C
Under be alternately repeated 60 seconds dilute atmosphere and 6 seconds dense atmosphere.Table 3 below shows dilute atmosphere and
The composition of the test gas of dense atmosphere, and in Figure 10 and Figure 11, show evaluation result.
[table 3]
It addition, be 20L/ minute by the flow rate set of test gas, by air speed (SV:Space
Velocity) it is set to 200000h-1.Being explained, air speed refers to the flow (body of test gas
Long-pending/h) value that obtains divided by sample volume.
Be explained, as " λ " of the intensity index of dilute atmosphere be defined as " oxidant equivalent/
Reducing agent equivalent ".Such as, dense atmosphere, stoichiometric proportion atmosphere and dilute atmosphere can use λ respectively
＜ 1, λ=1 and λ ＞ 1 represent.
As shown in Figure 10, during dilute atmosphere of 60 seconds, there is NO occlusion on sample
The most saturated, NOxThe trend that output (ppm) is gradually increased.It addition, as shown in Figure 10,
During the dense atmosphere of 6 seconds (during this period, owing to there is not NO in test gas, because of
This NOxOutput, die-offs) carry out so-called dense spike (rich spike) operation.And,
During dilute atmosphere of 60 seconds then, it is known that there is NO by sample gradually occlusion and NO
The trend that occlusion on sample is the most saturated.
Being explained, " dense spike " refers to the dense burning of very short time, thus can be by NOxInhale
Stay the NO of material institute occlusionxReduction.
Figure 11 is the enlarged drawing that with a portion of amplification about Figure 10.As shown in Figure 11,
NO with the sample of comparative example 1 'xOutput, is compared, the NO of the sample of embodiment 1 '～3 'x
Output, is less.
This is regarded as owing to the microgranule of catalyst metals contains Rh and Pd, and Rh and Pd
Coexisting with nanometer level, therefore Pd inhibits the oxidation of Rh, maintains the metallic state of Rh.
Thus, it is believed that in the sample of embodiment 1 '～3 ', due to its NOxDetergent power maintain or
Improve, NO can be purified fullyx, therefore NOxOutput, reduces.
Relatively, it is believed that in the sample of comparative example 1 ', the NO of RhxDetergent power because of
The oxidation of Rh etc. and deteriorate, and NO can not be purified under dense atmosphere fullyx.Therefore,
Due to the NO not being cleanedxIt is expelled directly out, therefore with the NO of the sample of embodiment 1 '～3 'x
Output, is compared, the NO of the sample of comparative example 1 'xOutput, increases.
Being explained, as shown in Figure 11, the peak of dense spike reduces with the order of embodiment 1 '～3 '.
This is regarded as because the content of the Pd in composition metal microgranule is the highest, and the oxidation of Rh is more subject to
To suppression.
" embodiment 4～11 "
The catalyst metals of embodiment 2 is being supported in the operation of dust carrier, is using 16g
By Al2O3And CeO2The dust carrier constituted replaces Al2O3-CeO2-ZrO2, and will burn
Thing is become to be immersed in the barium acetate solution of 11 mass % using will be as NOxThe barium of occlusion material carries
It is held in catalyst, in addition, in the same manner as the sample of the exhaust gas purifying catalyst of embodiment 2
(grain type, 1mm～1.7mm is straight for the sample of the exhaust gas purifying catalyst of preparation embodiment 4～11
Footpath, 3g).Being explained, the sample of the exhaust gas purifying catalyst of embodiment 4～11 is comprised
The Al of dust carrier2O3And CeO2Mass ratio be respectively 100:0,90:10,76:24,
71:29,60:40,50:50,40:60 and 20:80.
" comparative example 4～11 "
The catalyst metals of comparative example 1 is being supported in the operation of dust carrier, is using 16g
By Al2O3And CeO2The dust carrier constituted replaces Al2O3-CeO2-ZrO2, and will burn
Thing is become to be immersed in the barium acetate solution of 11 mass % using will be as NOxThe barium of occlusion material carries
It is held in catalyst, in addition, in the same manner as the sample of the exhaust gas purifying catalyst of comparative example 1
(grain type, 1mm～1.7mm is straight to prepare the sample of the exhaust gas purifying catalyst of comparative example 4～11
Footpath, 3g).Being explained, the sample of the exhaust gas purifying catalyst of comparative example 4～11 is comprised
The Al of dust carrier2O3And CeO2Mass ratio be respectively 100:0,90:10,76:24,
71:29,60:40,50:50,40:60 and 20:80.
" the evaluation B of catalyst "
About embodiment 4～11 and the sample of exhaust gas purifying catalyst of comparative example 4～11, comment
Valency is as NOxThe performance of occlusion reducing catalyst, it addition, for the sample of exhaust gas purifying catalyst
Product, by application heating reduction (TPR:Temperature Programmed Reduction)
Method evaluates reduction temperature.
＜ is as NOxThe performance evaluation B ＞ of occlusion reducing catalyst
As NOxIn performance evaluation B of occlusion reducing catalyst, use gas flow type
Catalyst test apparatus.Specifically, test gas is made to flow by this catalyst test apparatus,
By using infrared measure (FT-IR) to measure the group of the test gas after contacting with sample
Become.
Test gas is made up of dilute atmosphere and dense atmosphere, in this evaluation, the temperature of 400 DEG C
Lower 60 seconds dilute atmosphere and 6 seconds dense atmosphere are set to 1 circulation, repeat 5 circulations.It addition,
It is 20L/ minute by the flow rate set of test gas, air speed is set to 200000h-1.At following table
The composition of the test gas of dilute atmosphere and dense atmosphere is shown in 4, and at table 5 below, figure
The result of evaluation is shown in 13 and Figure 14.
Be explained, table 5 has been recorded embodiment 4～11 and the waste gas of comparative example 4～11 clean
Details (form of microgranule, Rh and Pd of the dust carrier that the sample of change catalyst has
Ratio, CeO in dust carrier2Content) and NOxOutput, is relative to NOxHold-up
Ratio (NOxOutput/NOxHold-up).It is explained, in table 5, " NOxRow
Output/NOxHold-up " be extract above-mentioned 5 circulation in 2～4 circulations, to they
NOxOutput/NOxThe value that hold-up carries out arithmetic average and obtains.
[table 4]
[table 5]
" the NO of table 5 is described with reference to Figure 12xOutput/NOxHold-up ".Figure 12 is to show
Go out as NOxIn performance evaluation B of occlusion reducing catalyst, by 60 seconds dilute atmosphere and 6
The NO that second dense atmosphere is constitutedxThe schematic diagram of occlusion reduction circulation.In fig. 12, dotted line represents
The content (necessarily) of the NO of the dilute atmosphere before contacting with the sample of exhaust gas purifying catalyst；“S1”
Region representation exhaust gas purifying catalyst under dilute atmosphere the occlusion of sample institute and/or absorption
NOxTotal amount (NOxHold-up)；Region (the also referred to as NO of " S2 "xSpike) represent
The NO not being reduced discharged from the sample of exhaust gas purifying catalyst under dense atmospherexTotal amount
(NOxOutput).That is, above-mentioned " NOxOutput/NOxHold-up " be equivalent to Figure 12
In " S2/S1 ".
(as NOxThe result of performance evaluation B of occlusion reducing catalyst)
Figure 13 is to illustrate embodiment 4～11 (●) and the waste gas purification of comparative example 4～11 (■)
CeO in dust carrier shown in the sample of catalyst2Content (quality %) and NOxDischarge
Amount/NOxThe figure of the relation of hold-up (a.u.).It is explained, about in dust carrier
CeO2Content (quality %) and NOxOutput/NOxThe relation of hold-up (a.u.), also
It is referred to table 5.
As shown in Figure 13, about the sample of the exhaust gas purifying catalyst of comparative example 4～11 (■),
Along with the CeO in dust carrier2Content rises, NOxOutput/NOxThe value line of hold-up
Property ground rise.This is regarded as due to the CeO in dust carrier2Content is the most, Rh oxide
Reduction get over by CeO2Suppression, and reducing agent (reducing agent such as such as hydrocarbon) is by this
Oxygen consumption.
It addition, as shown in Figure 13, about the exhaust gas purifying catalyst of embodiment 4～7 (●)
Sample, as the CeO in dust carrier2Content is in the scope more than 0 mass % and less than 29%
Time interior, NOxOutput/NOxThe value of hold-up is little and almost identical.This be regarded as due to
In the composition metal microgranule containing Rh and Pd, Pd can suppress the oxidation of Rh, therefore exists
Inhibit by CeO under dense atmosphere2The oxidation of the Rh caused, thus most of NO of institute's occlusionx
It is cleaned.
Being explained, as shown in Figure 13, the waste gas purification about embodiment 8～11 (●) is urged
The sample of agent, along with the CeO in dust carrier2Content is in 40 mass %～80 mass %
In the range of rise, NOxOutput/NOxThe value of hold-up rises linearly.But, by scheming
13 it is understood that about NOxOutput/NOxThe value of hold-up, is being respectively compared embodiment 8
With comparative example 8, embodiment 9 and comparative example 9, embodiment 10 and comparative example 10 and embodiment
11 and comparative example 11 in the case of, be all the NO of embodimentxOutput/NOxHold-up
It is worth less.“NOxOutput/NOxThe value of hold-up is little " represent that exhaust gas purifying catalyst is inhaled
The most of NO stayedxIt is cleaned.
Figure 14 is about embodiment 4～11 (●) and the waste gas purification of comparative example 4～11 (■)
The sample of catalyst, it is shown that the CeO in dust carrier2Content (quality %) and NOxPurify
The figure of the relation of rate (%).
As shown in Figure 14, the CeO in comparing these dust carriers2The embodiment that content is identical
With the exhaust gas purifying catalyst (such as, embodiment 7 and the combination of comparative example 7) of comparative example
In the case of, the NO of the exhaust gas purifying catalyst of embodimentxPurifying rate is clean higher than the waste gas of comparative example
Change the NO of catalystxPurifying rate.
It addition, from the curve of the embodiment of Figure 14, about the CeO in dust carrier2's
Content, more than 0 mass % (embodiment 4) and 40 mass % (embodiment 8) below
In the range of, it is achieved that extra high NOxPurifying rate.This be regarded as due to be combined with compound
Metal particle and CeO2Exhaust gas purifying catalyst in, under dilute atmosphere, improve NOxSuction
While attached amount, under dense atmosphere, improve the catalysis activity of Rh.
The evaluation B ＞ of ＜ reduction temperature
Carry out the evaluation of reduction temperature, show the result in Figure 16.
It is explained, specifically, by carrying out in the order coming by the operation of following (1)～(6)
Carry out the evaluation of reduction temperature:
(1) by the Sample introduction sample cell of 50mg exhaust gas purifying catalyst.
(2) according to gas generation apparatus, sample cell, desiccant and thermal conductivity detector (TCD) (TCD:
Thermal Conductivity Detector) order constitute evaluating apparatus.
(3) make by O2The gas that 10 volume % and helium 90 volume % are constituted with 30mL/ minute from
Gas generation apparatus passes through to sample cell flowing, makes gas with the programming rate of 20 DEG C/min simultaneously
The temperature of body is warming up to 500 DEG C.
(4), after the temperature at this gas reaches 500 DEG C, this constant temperature is maintained 10 minutes,
Thereafter the temperature of this gas is cooled to 50 DEG C.
(5) gas being made up of Ar 100 volume % is made to flow to sample cell from gas generation apparatus
Pass through.
(6) make by H21 volume % and Ar 99 volume % constitute gas with 30mL/ minute from
Gas generation apparatus passes through to sample cell flowing, makes gas with the programming rate of 10 DEG C/min simultaneously
The temperature of body is warming up to 500 DEG C.
Being explained, the effect of the desiccant of above-mentioned (2) is that capture is by the gas of sample cell
The water comprised.It addition, thermal conductivity detector (TCD) (TCD) measures along with the gas of gas componant change
The change of thermal conductivity, thus calculates the concentration of gas.
It addition, the sample of the exhaust gas purifying catalyst of above-mentioned (1) is respectively adopted embodiment 6 ' and compares
The sample of example 6 '.Embodiment 6 ' and comparative example 6 ' are respectively as embodiment 6 and comparative example 6
The sample that ground makes, except not carrying out as NOxThe barium of occlusion material be supported at carrier
Operation.
It is explained, about above-mentioned operation (1)～(6), figure 15 illustrates a series of flow process.
(result of the evaluation B of reduction temperature)
Figure 16 is to illustrate that the sample to embodiment 6 ' and the exhaust gas purifying catalyst of comparative example 6 ' should
By temperature during heating reduction (TPR:Temperature Programmed Reduction) method
(DEG C) and H2The figure of the relation of consumption (TCD signal) (a.u.).
In figure 16, solid line represents the sample of the exhaust gas purifying catalyst of embodiment 6 ', dotted line
Represent the sample of the exhaust gas purifying catalyst of comparative example 6 '.As shown in Figure 16, embodiment 6 '
The H of temperature2The peak of consumption is about 115 DEG C, and the H of the temperature of comparative example 6 '2Consumption
Peak be about 170 DEG C.It can thus be appreciated that, the compound gold of the exhaust gas purifying catalyst of embodiment 6 '
Belong to microgranule, Rh the most therein is converted into metal from its oxide at lower temperatures.
This is regarded as owing to, in this composition metal microgranule, Rh and Pd coexists with nanometer level,
Present the effect of the suppression Rh oxidation brought by Pd significantly.
Although describe the preferred embodiments of the invention in detail, but those skilled in the art's meeting
Understand, about the device used in the present invention, equipment and reagent etc., can to its manufacturer,
Grade and quality etc. are changed, without deviating from the scope of claims.
Claims (10)
1. exhaust gas purifying catalyst, it is to have the composition metal microgranule containing Rh and Pd
Exhaust gas purifying catalyst, wherein,
Utilizing STEM-EDX, the microgranule in described exhaust gas purifying catalyst is analyzed
Time, the average proportions of the Pd total relative to Rh and Pd is that 1.7 more than atom % 24.8 are former
Sub-below %,
Described average proportions is by value calculated as below: random from exhaust gas purifying catalyst
Select the microgranule of more than 10, utilize STEM-EDX to measure respectively selected whole micro-
Grain, selects whole containing described in Rh and Pd from selected whole microgranules further
Composition metal microgranule, amounts to the Pd of the described each composition metal microgranule conjunction relative to Rh and Pd
The ratio of meter, by this total divided by total number of selected whole described composition metal microgranule.
2. the exhaust gas purifying catalyst described in claim 1, it has dust carrier further,
And described composition metal microgranule is supported at described dust carrier.
3. the exhaust gas purifying catalyst described in claim 2, wherein, described dust carrier is choosing
From SiO2、MgO、ZrO2、CeO2、Al2O3、TiO2, their solid solution and it
The dust carrier of combination.
4. the exhaust gas purifying catalyst described in Claims 2 or 3, wherein, relative to described powder
The quality of end carrier, described dust carrier is to contain more than below 0 mass % and 40 mass %
CeO2。
5. exhaust gas purifying method, wherein, makes containing HC, CO under stoichiometric proportion atmosphere
And NOxWaste gas contact with the exhaust gas purifying catalyst described in any one of Claims 1 to 4,
Thus by HC and CO oxidation and by NOxThe most originally purified.
6. exhaust gas purifying method, wherein, makes containing NO under dilute atmospherexWaste gas and right
Require the exhaust gas purifying catalyst contact described in 1～4 any one, by described NO under dense atmospherex
The most originally purified.
7. the manufacture method of exhaust gas purifying catalyst, it is for including containing Rh ion, Pd
Ion, reducing agent and protectant solution are heated to reflux, and thus generate composition metal microgranule
The manufacture method of exhaust gas purifying catalyst, wherein,
The mol ratio of described Rh ion and described Pd ion is 70:30～99:1.
8. the method described in claim 7, it includes described composition metal microgranule is supported at powder
End carrier.
9. the method described in claim 8, wherein, described dust carrier is selected from SiO2、
MgO、ZrO2、CeO2、Al2O3、TiO2, their solid solution and combinations thereof
Dust carrier.
10. the method described in claim 8 or 9, wherein, relative to described dust carrier
Quality, described dust carrier is with more than containing CeO below 0 mass % and 40 mass %2。
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015-078958 | 2015-04-08 | ||
| JP2015078958 | 2015-04-08 | ||
| JP2015246776A JP6414043B2 (en) | 2015-04-08 | 2015-12-17 | Exhaust gas purification catalyst and method for producing the same |
| JP2015-246776 | 2015-12-17 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106040235A true CN106040235A (en) | 2016-10-26 |
| CN106040235B CN106040235B (en) | 2019-01-04 |
Family
ID=57423089
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610212807.0A Expired - Fee Related CN106040235B (en) | 2015-04-08 | 2016-04-07 | Exhaust gas purifying catalyst and its manufacturing method |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP6414043B2 (en) |
| CN (1) | CN106040235B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109954491A (en) * | 2017-12-26 | 2019-07-02 | 丰田自动车株式会社 | The manufacturing method and exhaust gas purification catalyst of exhaust gas purification catalyst |
| CN114471046A (en) * | 2022-02-16 | 2022-05-13 | 福建龙净环保股份有限公司 | Flue gas purification device and MTO regeneration flue gas purification process system |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108736030B (en) * | 2018-05-17 | 2020-12-25 | 福州大学 | Porous carbon-free catalyst for proton exchange membrane fuel cell and preparation method thereof |
| JP7099304B2 (en) * | 2018-12-19 | 2022-07-12 | トヨタ自動車株式会社 | Exhaust gas purification catalyst |
| JP7444762B2 (en) | 2020-07-28 | 2024-03-06 | トヨタ自動車株式会社 | Catalyst and exhaust gas purification device |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1176819A (en) * | 1997-09-09 | 1999-03-23 | Nissan Motor Co Ltd | Catalyst for cleaning of exhaust gas |
| JP2002102679A (en) * | 2000-09-29 | 2002-04-09 | Toyota Motor Corp | Composite metal colloid and its production method |
| JP2005161143A (en) * | 2003-12-01 | 2005-06-23 | Mazda Motor Corp | Catalyst material for cleaning exhaust gas and its method of production |
| CN101087651A (en) * | 2004-12-22 | 2007-12-12 | 日产自动车株式会社 | Exhaust gas purification catalyst and method for producing exhaust gas purification catalyst |
| JP2011078857A (en) * | 2009-10-02 | 2011-04-21 | Toyota Motor Corp | Exhaust gas cleaning catalyst for cleaning co or hc and method for manufacturing this catalyst |
| JP2013220377A (en) * | 2012-04-16 | 2013-10-28 | Cataler Corp | Exhaust gas purification catalyst |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4983684A (en) * | 1972-12-19 | 1974-08-12 | ||
| JPS5610334A (en) * | 1979-07-06 | 1981-02-02 | Toyota Motor Corp | Catalyst for cleaning up exhaust gas and manufacture of said catalyst |
| JP2716205B2 (en) * | 1989-05-08 | 1998-02-18 | 株式会社日本触媒 | Exhaust gas purification catalyst |
| US5212142A (en) * | 1991-11-04 | 1993-05-18 | Engelhard Corporation | High performance thermally stable catalyst |
| JP4969843B2 (en) * | 2005-12-09 | 2012-07-04 | 新日鉄マテリアルズ株式会社 | Exhaust gas purification catalyst and exhaust gas purification catalyst member |
| WO2014169235A1 (en) * | 2013-04-12 | 2014-10-16 | Board Of Regents, The University Of Texas System | Synthesis of bimetallic nanoparticle catalysts using microwave irradiation |
-
2015
- 2015-12-17 JP JP2015246776A patent/JP6414043B2/en active Active
-
2016
- 2016-04-07 CN CN201610212807.0A patent/CN106040235B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1176819A (en) * | 1997-09-09 | 1999-03-23 | Nissan Motor Co Ltd | Catalyst for cleaning of exhaust gas |
| JP2002102679A (en) * | 2000-09-29 | 2002-04-09 | Toyota Motor Corp | Composite metal colloid and its production method |
| JP2005161143A (en) * | 2003-12-01 | 2005-06-23 | Mazda Motor Corp | Catalyst material for cleaning exhaust gas and its method of production |
| CN101087651A (en) * | 2004-12-22 | 2007-12-12 | 日产自动车株式会社 | Exhaust gas purification catalyst and method for producing exhaust gas purification catalyst |
| JP2011078857A (en) * | 2009-10-02 | 2011-04-21 | Toyota Motor Corp | Exhaust gas cleaning catalyst for cleaning co or hc and method for manufacturing this catalyst |
| JP2013220377A (en) * | 2012-04-16 | 2013-10-28 | Cataler Corp | Exhaust gas purification catalyst |
Non-Patent Citations (1)
| Title |
|---|
| RENZAS JAMES RUSSELL ET AL.: ""Rh1-xPdx nanoparticle composition dependence in CO oxidation by oxygen: catalytic activityenhancement in bimetallic systems"", 《PHYSICAL CHEMISTRY CHEMICAL PHYSICS》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109954491A (en) * | 2017-12-26 | 2019-07-02 | 丰田自动车株式会社 | The manufacturing method and exhaust gas purification catalyst of exhaust gas purification catalyst |
| CN114471046A (en) * | 2022-02-16 | 2022-05-13 | 福建龙净环保股份有限公司 | Flue gas purification device and MTO regeneration flue gas purification process system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6414043B2 (en) | 2018-10-31 |
| JP2016198759A (en) | 2016-12-01 |
| CN106040235B (en) | 2019-01-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106040235A (en) | Exhaust gas purification catalyst and method for producing the same | |
| Machida et al. | On the reasons for high activity of CeO2 catalyst for soot oxidation | |
| US9616386B2 (en) | Catalyst for purification of exhaust gas, NOx storage-reduction catalyst, and method for purifying exhaust gas | |
| US8252257B2 (en) | Method for purifying gas, gas purifying apparatus, and gas purifying catalyst | |
| JP4090547B2 (en) | Exhaust gas purification catalyst | |
| JP2002282689A (en) | Catalyst carrier and catalyst, and method for producing them | |
| Wang et al. | Promoted soot oxidation by doped K2Ti2O5 catalysts and NO oxidation catalysts | |
| Nascimento et al. | Ru-doped ceria–zirconia mixed oxides catalyze soot combustion | |
| US9795945B2 (en) | Exhaust gas purification catalyst and method for producing the same | |
| JP2013027858A (en) | Exhaust gas-purifying catalyst | |
| Nascimento et al. | Catalytic combustion of soot over Ru-doped mixed oxides catalysts | |
| Tepluchin et al. | Study on the hydrothermal and SO2 stability of Al2O3-supported manganese and iron oxide catalysts for lean CO oxidation | |
| Liu et al. | Optimization and comprehensive mechanism of environment-friendly bimetal oxides catalysts for efficient removal of NO in ultra-low temperature flue gas | |
| CN102864004B (en) | A kind of High-activity oxygen carrier and its preparation method and application | |
| US20050221979A1 (en) | Purification catalyst for exhaust gas | |
| JP7020110B2 (en) | Manufacturing method of catalyst for exhaust gas purification and catalyst for exhaust gas purification | |
| JP4998350B2 (en) | Exhaust gas purification catalyst | |
| JP2007000773A (en) | Catalyst carrier and its manufacturing method, and catalyst for cleaning exhaust gas | |
| CN104001508B (en) | Exhaust gas catalytic conversion and preparation method thereof | |
| JP4254208B2 (en) | Internal combustion engine exhaust gas purification device, purification method and catalyst | |
| JP2008137886A (en) | Oxide composite precursor aqueous solution, method of manufacturing oxide composite, oxide composite, exhaust cleaning catalyst provided with the oxide composite, and method of cleaning exhaust using the exhaust cleaning catalyst | |
| CN105363441A (en) | NOx STORAGE REDUCTION CATALYST AND PRODUCTION METHOD THEREOF | |
| US9266093B2 (en) | Exhaust gas purification catalyst and method for producing the same | |
| CN112879127B (en) | Exhaust gas purification system | |
| Wang et al. | Simultaneous Removal of Soot and NO x from Lean-Burn Engine Emissions Over Potassium Dititanate-Based Catalysts |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20190104 |