JP5169779B2 - Nitrogen oxide purification catalyst and nitrogen oxide purification method - Google Patents
Nitrogen oxide purification catalyst and nitrogen oxide purification method Download PDFInfo
- Publication number
- JP5169779B2 JP5169779B2 JP2008309424A JP2008309424A JP5169779B2 JP 5169779 B2 JP5169779 B2 JP 5169779B2 JP 2008309424 A JP2008309424 A JP 2008309424A JP 2008309424 A JP2008309424 A JP 2008309424A JP 5169779 B2 JP5169779 B2 JP 5169779B2
- Authority
- JP
- Japan
- Prior art keywords
- iron
- nitrogen oxide
- silicate
- isolated
- present
- 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.)
- Active
Links
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 title claims description 152
- 239000003054 catalyst Substances 0.000 title claims description 34
- 238000000746 purification Methods 0.000 title claims description 31
- 238000000034 method Methods 0.000 title claims description 22
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 289
- 229910052742 iron Inorganic materials 0.000 claims description 153
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims description 74
- -1 iron ion Chemical class 0.000 claims description 43
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 22
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 14
- 239000003638 chemical reducing agent Substances 0.000 claims description 8
- 229910021529 ammonia Inorganic materials 0.000 claims description 7
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 3
- 150000001412 amines Chemical class 0.000 claims description 3
- 239000004202 carbamide Substances 0.000 claims description 3
- GQPLMRYTRLFLPF-UHFFFAOYSA-N Nitrous Oxide Chemical compound [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 description 44
- 238000010521 absorption reaction Methods 0.000 description 28
- 238000005259 measurement Methods 0.000 description 28
- 239000000203 mixture Substances 0.000 description 22
- 239000007789 gas Substances 0.000 description 19
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 15
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 14
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 12
- 238000002441 X-ray diffraction Methods 0.000 description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 11
- 229910001868 water Inorganic materials 0.000 description 11
- 239000011541 reaction mixture Substances 0.000 description 10
- 238000002425 crystallisation Methods 0.000 description 9
- 230000008025 crystallization Effects 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 229910000323 aluminium silicate Inorganic materials 0.000 description 8
- 238000001362 electron spin resonance spectrum Methods 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 8
- 239000002184 metal Substances 0.000 description 8
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 8
- 239000010457 zeolite Substances 0.000 description 8
- 238000004435 EPR spectroscopy Methods 0.000 description 7
- 229910021536 Zeolite Inorganic materials 0.000 description 7
- 239000013078 crystal Substances 0.000 description 7
- 239000007788 liquid Substances 0.000 description 7
- 239000000843 powder Substances 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 6
- 238000011068 loading method Methods 0.000 description 6
- 229910052757 nitrogen Inorganic materials 0.000 description 6
- 238000006722 reduction reaction Methods 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 229910052782 aluminium Inorganic materials 0.000 description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 230000003197 catalytic effect Effects 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 229910052802 copper Inorganic materials 0.000 description 5
- 239000010949 copper Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 5
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 4
- 238000000862 absorption spectrum Methods 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 4
- 238000002485 combustion reaction Methods 0.000 description 4
- 238000000354 decomposition reaction Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 239000001272 nitrous oxide Substances 0.000 description 4
- 229910052697 platinum Inorganic materials 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 229910001220 stainless steel Inorganic materials 0.000 description 4
- 239000010935 stainless steel Substances 0.000 description 4
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 3
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000006555 catalytic reaction Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 229910017052 cobalt Inorganic materials 0.000 description 3
- 239000010941 cobalt Substances 0.000 description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 3
- 239000011737 fluorine Substances 0.000 description 3
- 229910052731 fluorine Inorganic materials 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- 238000005342 ion exchange Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910052763 palladium Inorganic materials 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 238000010531 catalytic reduction reaction Methods 0.000 description 2
- 239000002734 clay mineral Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 238000007429 general method Methods 0.000 description 2
- 238000005470 impregnation Methods 0.000 description 2
- MVFCKEFYUDZOCX-UHFFFAOYSA-N iron(2+);dinitrate Chemical compound [Fe+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MVFCKEFYUDZOCX-UHFFFAOYSA-N 0.000 description 2
- NROKBHXJSPEDAR-UHFFFAOYSA-M potassium fluoride Chemical compound [F-].[K+] NROKBHXJSPEDAR-UHFFFAOYSA-M 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- CBXCPBUEXACCNR-UHFFFAOYSA-N tetraethylammonium Chemical compound CC[N+](CC)(CC)CC CBXCPBUEXACCNR-UHFFFAOYSA-N 0.000 description 2
- 229940073455 tetraethylammonium hydroxide Drugs 0.000 description 2
- QSUJAUYJBJRLKV-UHFFFAOYSA-M tetraethylazanium;fluoride Chemical compound [F-].CC[N+](CC)(CC)CC QSUJAUYJBJRLKV-UHFFFAOYSA-M 0.000 description 2
- LRGJRHZIDJQFCL-UHFFFAOYSA-M tetraethylazanium;hydroxide Chemical compound [OH-].CC[N+](CC)(CC)CC LRGJRHZIDJQFCL-UHFFFAOYSA-M 0.000 description 2
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 1
- XNDZQQSKSQTQQD-UHFFFAOYSA-N 3-methylcyclohex-2-en-1-ol Chemical compound CC1=CC(O)CCC1 XNDZQQSKSQTQQD-UHFFFAOYSA-N 0.000 description 1
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 1
- DDFHBQSCUXNBSA-UHFFFAOYSA-N 5-(5-carboxythiophen-2-yl)thiophene-2-carboxylic acid Chemical compound S1C(C(=O)O)=CC=C1C1=CC=C(C(O)=O)S1 DDFHBQSCUXNBSA-UHFFFAOYSA-N 0.000 description 1
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- 239000005995 Aluminium silicate Substances 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 1
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- 239000004113 Sepiolite Substances 0.000 description 1
- 239000004115 Sodium Silicate Substances 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 239000003929 acidic solution Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910001583 allophane Inorganic materials 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 description 1
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 229960000892 attapulgite Drugs 0.000 description 1
- 239000000440 bentonite Substances 0.000 description 1
- 229910000278 bentonite Inorganic materials 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- LPCWKMYWISGVSK-UHFFFAOYSA-N bicyclo[3.2.1]octane Chemical compound C1C2CCC1CCC2 LPCWKMYWISGVSK-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000008119 colloidal silica Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- 150000004292 cyclic ethers Chemical class 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- GUJOJGAPFQRJSV-UHFFFAOYSA-N dialuminum;dioxosilane;oxygen(2-);hydrate Chemical compound O.[O-2].[O-2].[O-2].[Al+3].[Al+3].O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O GUJOJGAPFQRJSV-UHFFFAOYSA-N 0.000 description 1
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 238000001027 hydrothermal synthesis Methods 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- FBAFATDZDUQKNH-UHFFFAOYSA-M iron chloride Chemical compound [Cl-].[Fe] FBAFATDZDUQKNH-UHFFFAOYSA-M 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- 235000013980 iron oxide Nutrition 0.000 description 1
- 229910000358 iron sulfate Inorganic materials 0.000 description 1
- QZRHHEURPZONJU-UHFFFAOYSA-N iron(2+) dinitrate nonahydrate Chemical compound O.O.O.O.O.O.O.O.O.[Fe+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O QZRHHEURPZONJU-UHFFFAOYSA-N 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 1
- 238000006317 isomerization reaction Methods 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052901 montmorillonite Inorganic materials 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- UFWIBTONFRDIAS-UHFFFAOYSA-N naphthalene-acid Natural products C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 229940078552 o-xylene Drugs 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 229910052625 palygorskite Inorganic materials 0.000 description 1
- 230000005298 paramagnetic effect Effects 0.000 description 1
- 229920001515 polyalkylene glycol Polymers 0.000 description 1
- 239000002685 polymerization catalyst Substances 0.000 description 1
- 239000011698 potassium fluoride Substances 0.000 description 1
- 235000003270 potassium fluoride Nutrition 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 238000007151 ring opening polymerisation reaction Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000011935 selective methylation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052624 sepiolite Inorganic materials 0.000 description 1
- 235000019355 sepiolite Nutrition 0.000 description 1
- 150000004760 silicates Chemical group 0.000 description 1
- 229910001388 sodium aluminate Inorganic materials 0.000 description 1
- 239000011775 sodium fluoride Substances 0.000 description 1
- 235000013024 sodium fluoride Nutrition 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 229910052911 sodium silicate Inorganic materials 0.000 description 1
- 239000011973 solid acid Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical class S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 description 1
- 229910052815 sulfur oxide Inorganic materials 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- HWCKGOZZJDHMNC-UHFFFAOYSA-M tetraethylammonium bromide Chemical compound [Br-].CC[N+](CC)(CC)CC HWCKGOZZJDHMNC-UHFFFAOYSA-M 0.000 description 1
- OSBSFAARYOCBHB-UHFFFAOYSA-N tetrapropylammonium Chemical class CCC[N+](CCC)(CCC)CCC OSBSFAARYOCBHB-UHFFFAOYSA-N 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- IMNIMPAHZVJRPE-UHFFFAOYSA-N triethylenediamine Chemical compound C1CN2CCN1CC2 IMNIMPAHZVJRPE-UHFFFAOYSA-N 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
Images
Classifications
-
- 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
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/30—Capture or disposal of greenhouse gases of perfluorocarbons [PFC], hydrofluorocarbons [HFC] or sulfur hexafluoride [SF6]
Description
本発明は、内燃機関から排出される窒素酸化物の浄化に関するものであり、β構造を有する鉄シリケートからなる窒素酸化物浄化触媒、並びにそれを用いてアンモニア、尿素、有機アミン類の少なくとも一つと反応させる窒素酸化物浄化方法を提供するものである。 The present invention relates to the purification of nitrogen oxides discharged from an internal combustion engine, a nitrogen oxide purification catalyst comprising an iron silicate having a β structure, and at least one of ammonia, urea, and organic amines using the catalyst. The present invention provides a method for purifying nitrogen oxides to be reacted.
骨格構造中に異種元素を置換したシリケートは、通常のアルミノシリケートゼオライトとは異なる特性が期待され、触媒反応への利用が検討されている。 Silicates substituted with different elements in the skeletal structure are expected to have different properties from ordinary aluminosilicate zeolites, and their use in catalytic reactions is being investigated.
例えば白金を担持した鉄シリケートを用いたキシレン異性化触媒（特許文献１）、また鉄シリケートを用いたナフタレン性化合物の選択メチル化触媒（特許文献２）、また環状エーテルの開環重合触媒として鉄シリケートを用いたポリアルキレングリコールの製造方法（特許文献３）等が開示されている。 For example, iron as a xylene isomerization catalyst using an iron silicate carrying platinum (Patent Document 1), a selective methylation catalyst of a naphthalene compound using an iron silicate (Patent Document 2), and a ring-opening polymerization catalyst of a cyclic ether A method for producing polyalkylene glycol using silicate (Patent Document 3) and the like are disclosed.
一方、鉄シリケートを用いた窒素酸化物の浄化技術も検討されている。 On the other hand, nitrogen oxide purification technology using iron silicate is also being studied.
例えば、ＺＳＭ−５型鉄シリケートに銅とガリウムとの共沈複合酸化物が分散担持された窒素酸化物を含む排ガスの浄化用触媒（特許文献４）、過剰の酸素が存在する雰囲気中で、炭化水素類または含酸素化合物の存在下、ＺＳＭ−５型鉄シリケートのアルカリ金属交換体を窒素酸化物を含む排ガスと接触させる窒素酸化物浄化方法（特許文献５）、窒素酸化物、酸素ガスおよび必要に応じて亜硫酸ガスを含有する燃焼排ガスを、鉄シリケート触媒および炭化水素還元剤の存在下で接触反応させる窒素酸化物の除去方法（特許文献６）、鉄シリケートに白金、パラジウム、ロジウム及びコバルトのうち少なくとも一種を担持した窒素酸化物を主として除去する排気ガス浄化触媒（特許文献７）等が報告されている。 For example, a catalyst for purifying exhaust gas containing nitrogen oxide in which a coprecipitation complex oxide of copper and gallium is dispersed and supported on ZSM-5 type iron silicate (Patent Document 4), in an atmosphere where excess oxygen exists, Nitrogen oxide purification method (patent document 5) in which an alkali metal exchanger of ZSM-5 type iron silicate is contacted with exhaust gas containing nitrogen oxide in the presence of hydrocarbons or oxygen-containing compounds, nitrogen oxide, oxygen gas, and Nitrogen oxide removal method in which combustion exhaust gas containing sulfurous acid gas is contact-reacted in the presence of an iron silicate catalyst and a hydrocarbon reducing agent as required (Patent Document 6), platinum, palladium, rhodium and cobalt on iron silicate Among them, an exhaust gas purification catalyst that mainly removes nitrogen oxides supporting at least one of them (Patent Document 7) has been reported.
なお、特許文献６、７に記載される鉄シリケートは合成の際にテトラプロピルアンモニウム塩を使用していることから、得られた鉄シリケートの骨格構造はＺＳＭ−５構造であると予測される。 In addition, since the iron silicate described in Patent Documents 6 and 7 uses a tetrapropylammonium salt at the time of synthesis, the skeleton structure of the obtained iron silicate is predicted to be a ZSM-5 structure.
亜酸化窒素の浄化触媒については、亜酸化窒素の直接分解に用いられる、銅やコバルト等を担持したβ型鉄シリケートを含む触媒の製造方法（特許文献８）、β構造を有する鉄シリケートを用いて、亜酸化窒素を直接分解する方法、及び一酸化炭素を還元剤として亜酸化窒素を非選択的接触還元する方法（非特許文献１）等が開示されている。 As for the purification catalyst for nitrous oxide, a method for producing a catalyst containing β-type iron silicate supporting copper, cobalt, etc., used for direct decomposition of nitrous oxide (Patent Document 8), an iron silicate having a β structure is used. In addition, a method of directly decomposing nitrous oxide, a method of non-selective catalytic reduction of nitrous oxide using carbon monoxide as a reducing agent (Non-patent Document 1), and the like are disclosed.
一方、排ガス中の窒素酸化物の浄化触媒については、リーンバーン燃焼排ガスやディーゼル燃焼排ガスに代表される酸素過剰排ガスの窒素酸化物の浄化に関し、鉄又は銅を担持したアルミノシリケートゼオライト触媒を用い、アンモニアにより選択的接触還元（通常ＳＣＲという）する方法（特許文献９）が知られている。 On the other hand, for the purification catalyst of nitrogen oxides in exhaust gas, with respect to the purification of nitrogen oxides of oxygen excess exhaust gas represented by lean burn combustion exhaust gas and diesel combustion exhaust gas, an aluminosilicate zeolite catalyst supporting iron or copper is used, A method of selective catalytic reduction (usually referred to as SCR) with ammonia (Patent Document 9) is known.
しかし、アンモニアを還元剤として用いた窒素酸化物（ＮＯｘ）の還元方法において、低温での窒素酸化物の分解性能並びに水熱耐久性に優れた鉄シリケートはこれまで知られていなかった。 However, in a method for reducing nitrogen oxide (NOx) using ammonia as a reducing agent, an iron silicate excellent in nitrogen oxide decomposition performance at low temperature and hydrothermal durability has not been known so far.
排出ガス中の窒素酸化物の効率的な浄化が望まれている中で、従来、２５０℃以下の低温における窒素酸化物浄化活性が高く、なおかつ水熱耐久性能の高い窒素酸化物浄化触媒は得られていなかった。 While efficient purification of nitrogen oxides in exhaust gas is desired, a nitrogen oxide purification catalyst having high nitrogen oxide purification activity at a low temperature of 250 ° C. or lower and high hydrothermal durability performance has been obtained. It was not done.
本発明の目的は、幅広い温度域、特に２５０℃以下の比較的低温の領域で効率的に窒素酸化物を浄化する触媒性能を有し、かつ従来よりも優れた水熱耐久性を有する鉄シリケート触媒を提供することにある。 An object of the present invention is an iron silicate having catalytic performance for efficiently purifying nitrogen oxides in a wide temperature range, particularly in a relatively low temperature range of 250 ° C. or less, and having hydrothermal durability superior to conventional ones. It is to provide a catalyst.
さらに他の目的は、上記触媒を用いた窒素酸化物の浄化方法を提供することにある。 Still another object is to provide a method for purifying nitrogen oxides using the above catalyst.
本発明者らは、アンモニア等を用いた窒素酸化物の選択還元（ＳＣＲ）について鋭意検討を重ねた結果、ＳｉＯ２／Ｆｅ２Ｏ３モル比が２０〜３００、ミクロ孔中に有機構造指向剤（Ｓｔｒｕｃｔｕｒｅ Ｄｉｒｅｃｔｉｎｇ Ａｇｅｎｔ）（以下、「ＳＤＡ」と呼称する）を含まない状態（以下、フレッシュと呼称する）において含有鉄の８０％以上が孤立鉄イオンであるβ骨格構造中に鉄を有する結晶性シリケートでは、アンモニア等を還元剤とする窒素酸化物の選択還元において、優れた窒素酸化物の浄化性能を有していることを見出し、本発明を完成させるに至ったものである。 The present inventors have found that selective reduction of nitrogen oxides with ammonia (SCR) result of intensive studies for, SiO 2 / Fe 2 O 3 molar ratio of 20 to 300, an organic structure directing agent in the micropores (Structure Directing Agent) (hereinafter referred to as “SDA”) (hereinafter referred to as “fresh”) 80% or more of the contained iron is an isolated iron ion. The silicate has been found to have excellent nitrogen oxide purification performance in the selective reduction of nitrogen oxide using ammonia or the like as a reducing agent, and has completed the present invention.
以下、本発明の窒素酸化物浄化触媒について説明する。 Hereinafter, the nitrogen oxide purification catalyst of the present invention will be described.
本発明の窒素酸化物浄化触媒は、β骨格構造中に鉄を有する結晶性シリケート（以下、「β型鉄シリケート」と呼称する）であって、ＳｉＯ２／Ｆｅ２Ｏ３モル比が２０〜３００、フレッシュにおいて含有鉄中の８０％以上が孤立鉄イオンである。 The nitrogen oxide purification catalyst of the present invention is a crystalline silicate having iron in a β skeleton structure (hereinafter referred to as “β-type iron silicate”), and has a SiO 2 / Fe 2 O 3 molar ratio of 20 to 300, 80% or more of the contained iron in fresh is isolated iron ions.
本発明のβ型鉄シリケートの組成は、
（ｘ＋ｙ）Ｍ（２／ｎ）Ｏ・ｘＦｅ２Ｏ３・ｙＡｌ２Ｏ３・ｚＳｉＯ２・ｗＨ２Ｏ
（但し、ｎは陽イオンＭの原子価、ｘ、ｙ、ｚ、はそれぞれＦｅ２Ｏ３、Ａｌ２Ｏ３、ＳｉＯ２のモル分率を表し、ｘ＋ｙ＋ｚ＝１である。ｗは０以上の数であり、ｙは０であってもよい）で表される。
The composition of the β-type iron silicate of the present invention is:
(X + y) M (2 / n) O.xFe 2 O 3 .yAl 2 O 3 .zSiO 2 .wH 2 O
(Where n is the valence of the cation M, x, y, and z are mole fractions of Fe 2 O 3 , Al 2 O 3 , and SiO 2 , respectively, and x + y + z = 1. W is 0 or more. And y may be 0).
本発明のβ型鉄シリケートの結晶構造は、Ｘ線回折で確認される結晶構造がβ型である。β型鉄シリケートは、酸素１２員環からなる０．７６×０．６４ｎｍおよび０．５５×０．５５ｎｍの細孔が交差した３次元細孔を有するメタロシリケートである。β型鉄シリケートのＸ線回折パターンは以下の表１に示す格子面間隔ｄ（オングストローム）とその回折強度で特徴付けられる。 The crystal structure of the β-type iron silicate of the present invention is β-type as confirmed by X-ray diffraction. β-type iron silicate is a metallosilicate having three-dimensional pores in which 0.76 × 0.64 nm and 0.55 × 0.55 nm pores composed of oxygen 12-membered rings intersect. The X-ray diffraction pattern of β-type iron silicate is characterized by the lattice spacing d (angstrom) shown in Table 1 below and its diffraction intensity.
ＳｉＯ２／Ｆｅ２Ｏ３モル比が２０未満では鉄の合計含有量は多くなるが、耐熱水処理によって結晶性が低下しやすく、活性に寄与する孤立Ｆｅ３＋を十分に保持することが難しい。結晶性の観点からは、ＳｉＯ２／Ｆｅ２Ｏ３モル比は特に２５以上が好ましい。 If the SiO 2 / Fe 2 O 3 molar ratio is less than 20, the total iron content increases, but the crystallinity is likely to be lowered by the hot water treatment, and it is difficult to sufficiently retain isolated Fe 3+ that contributes to activity. From the viewpoint of crystallinity, the SiO 2 / Fe 2 O 3 molar ratio is particularly preferably 25 or more.
一方ＳｉＯ２／Ｆｅ２Ｏ３モル比３００を超えるものでは、絶対的な鉄イオン量が少なく、十分な触媒活性が得られない。 On the other hand, when the SiO 2 / Fe 2 O 3 molar ratio exceeds 300, the absolute iron ion amount is small and sufficient catalytic activity cannot be obtained.
ＳｉＯ２／Ｆｅ２Ｏ３モル比は４０〜１５０、さらに５０〜８０の範囲であることが好ましい。 The SiO 2 / Fe 2 O 3 molar ratio is preferably in the range of 40 to 150, more preferably 50 to 80.
なお、本発明のβ型鉄シリケート中で窒素酸化物の還元に最も寄与する鉄は、後述するシリケート骨格中に孤立鉄イオン（Ｆｅ３＋）として分散して存在するものであり、Ｆｅ２Ｏ３として凝集しているものではない。本発明のβ型鉄シリケートの組成の定義で用いているＳｉＯ２／Ｆｅ２Ｏ３モル比は、孤立鉄イオンを含む全ての鉄含有量を定義するために便宜上に用いられる表記である。 The iron that contributes most to the reduction of nitrogen oxides in the β-type iron silicate of the present invention is dispersed as isolated iron ions (Fe 3+ ) in the silicate skeleton described later, and Fe 2 O 3 Not agglomerated. The SiO 2 / Fe 2 O 3 molar ratio used in the definition of the composition of the β-type iron silicate of the present invention is a notation used for convenience to define the total iron content including isolated iron ions.
本発明のβ型鉄シリケートは、フレッシュにおいて含有鉄中の８０％以上が孤立鉄イオンである。 In the β-type iron silicate of the present invention, 80% or more of the contained iron in the fresh is isolated iron ions.
本発明のβ型鉄シリケートは、四配位構造の鉄が骨格原子として酸素原子と連結した構造を有し、アルミノシリケートゼオライトと同様にシリケート骨格の電荷不足に由来する固体酸性質を有するものである。本発明の鉄シリケートは、通常のアルミノシリケートゼオライトに鉄を担持した触媒に比べ、触媒の活性金属としての鉄が高度に分散した孤立鉄イオン（Ｆｅ３＋）として存在しており、アンモニア等を用いた選択還元反応において、鉄の凝集が抑制され、特に高い性能が発揮される。 The β-type iron silicate of the present invention has a structure in which four-coordinate iron is connected to an oxygen atom as a skeleton atom, and has a solid acid property derived from a lack of charge in the silicate skeleton as in the case of an aluminosilicate zeolite. is there. The iron silicate of the present invention exists as isolated iron ions (Fe 3+ ) in which iron as a catalyst active metal is highly dispersed compared to a catalyst in which iron is supported on a normal aluminosilicate zeolite. In the selective reduction reaction, iron aggregation is suppressed, and particularly high performance is exhibited.
β型鉄シリケートにおける孤立鉄イオンは紫外可視吸光測定で測定することができる。 Isolated iron ions in β-type iron silicate can be measured by UV-visible absorption measurement.
紫外可視吸光測定における孤立鉄イオンの比率は、紫外可視吸収スペクトルの波長領域２２０〜７００ｎｍの範囲において、全吸収積分強度（Ｂ）に対し、ピーク波長２１１±１０ｎｍの積分吸収強度（Ｃ）及びピーク波長２７２±１０ｎｍの積分吸収強度（Ｄ）の比（Ａ＝（Ｃ＋Ｄ）／Ｂ）によって求められる。 The ratio of isolated iron ions in the UV-visible absorption measurement is as follows: the integrated absorption intensity (C) and the peak wavelength 211 ± 10 nm with respect to the total absorption integrated intensity (B) and the peak in the wavelength range 220 to 700 nm of the UV-visible absorption spectrum It is calculated | required by ratio (A = (C + D) / B) of the integral absorption intensity | strength (D) of wavelength 272 +/- 10nm.
鉄イオン又は鉄酸化物は紫外及び可視光の波長領域に吸収を示す。紫外可視吸光測定における、鉄の吸収波長領域はその存在状態によって異なり、３００ｎｍ未満の吸収は孤立鉄イオン（Ｆｅ３＋）に、３００〜４００ｎｍの範囲の吸収はＦｅ２Ｏ３クラスターに、４００ｎｍを超える吸収はＦｅ２Ｏ３凝集粒子に帰属される。即ち、紫外可視吸収スペクトルにおけるピーク波長約２１１±１０ｎｍ及び約２７２±１０ｎｍのガウス曲線よりなる分解波形Ｃ及びＤは孤立鉄イオンに基づく吸収に帰属される。孤立鉄イオンは、主にβ型鉄シリケートの骨格又はイオン交換サイトに位置するＦｅ３＋からなり、高分散状態で存在する鉄に帰属される。 Iron ions or iron oxides absorb in the ultraviolet and visible wavelength regions. In the UV-Vis absorption measurement, the absorption wavelength region of iron varies depending on the state of existence, absorption less than 300 nm is in isolated iron ions (Fe 3+ ), absorption in the range of 300 to 400 nm is in Fe 2 O 3 clusters, and exceeds 400 nm. Absorption is attributed to Fe 2 O 3 aggregated particles. That is, the decomposition waveforms C and D consisting of Gaussian curves with peak wavelengths of about 211 ± 10 nm and about 272 ± 10 nm in the UV-visible absorption spectrum are attributed to absorption based on isolated iron ions. The isolated iron ion is mainly composed of Fe 3+ located at the skeleton of the β-type iron silicate or the ion exchange site, and is attributed to iron existing in a highly dispersed state.
鉄が骨格外で凝集して窒素酸化物浄化機能が低いβ型鉄シリケートでは孤立鉄イオンの比率が小さくなる。本発明のβ型鉄シリケートでは含有鉄中の孤立鉄イオンの比率が８０％以上、特に９０％以上さらには９５％以上であることが好ましい。孤立鉄イオンの比率の上限は、理論的には１００％を超えることはない。 In β-type iron silicate, where iron aggregates outside the skeleton and has a low nitrogen oxide purification function, the ratio of isolated iron ions decreases. In the β-type iron silicate of the present invention, the ratio of isolated iron ions in the contained iron is preferably 80% or more, particularly 90% or more, more preferably 95% or more. The upper limit of the ratio of isolated iron ions does not theoretically exceed 100%.
紫外可視吸光測定には、以下の一般的な方法が用いられる。 The following general methods are used for UV-visible absorption measurement.
すなわち、積分球付属装置（例えば（株）島津製作所製のＩＳＲ−３１００）を試料室に取り付けた自記分光光度計（（株）島津製作所製のＵＶ−３１００）を用いて紫外可視吸光の測定が行われる。スキャンスピードは２００ｎｍ／ｍｉｎ、スリット幅は５．０ｎｍとし、ベースライン補正には硫酸バリウム粉末が用られる。粉末化した試料は、試料フォルダに充填し、波長範囲２２０〜７００ｎｍにおける反射率を測定すればよい。 That is, the measurement of ultraviolet-visible light absorption was performed using a self-recording spectrophotometer (UV-3100, manufactured by Shimadzu Corporation) equipped with an integrating sphere attachment device (for example, ISR-3100 manufactured by Shimadzu Corporation) attached to the sample chamber. Done. The scan speed is 200 nm / min, the slit width is 5.0 nm, and barium sulfate powder is used for baseline correction. The powdered sample may be filled in a sample folder and the reflectance in the wavelength range of 220 to 700 nm may be measured.
なお、水熱合成直後のβ型鉄シリケートはそのミクロ孔中にテトラエチルアンモニウムカチオン等の有機構造指向剤を含有しているため、紫外可視吸収スペクトルの測定は、乾燥空気又は窒素等の雰囲気下、β型鉄シリケートを６００℃で焼成することにより通常行われるＳＤＡの除去操作（以下、フレッシュ焼成と呼称する）後に行う。 In addition, since β-type iron silicate immediately after hydrothermal synthesis contains an organic structure directing agent such as tetraethylammonium cation in the micropores, the measurement of the UV-visible absorption spectrum is performed under an atmosphere such as dry air or nitrogen, This is performed after the SDA removal operation (hereinafter referred to as “fresh baking”), which is usually performed by baking β-type iron silicate at 600 ° C.
本発明のβ型鉄シリケートは、含有する鉄イオンの８０％以上が孤立Ｆｅ３＋であるが、孤立Ｆｅ３＋は対称四面体構造を有していることが好ましく、対称四面体構造を有する孤立Ｆｅ３＋の比率が含有鉄の２０％以上であることが好ましい。 In the β-type iron silicate of the present invention, 80% or more of the iron ions contained are isolated Fe 3+ , but the isolated Fe 3+ preferably has a symmetric tetrahedral structure, and the isolated Fe 3+ has a symmetric tetrahedral structure. The 3+ ratio is preferably 20% or more of the contained iron.
鉄成分の構造対称性は、電子スピン共鳴測定（測定温度７７Ｋ）で測定することができる。 The structural symmetry of the iron component can be measured by electron spin resonance measurement (measurement temperature 77K).
常磁性の鉄イオン（Ｆｅ３＋）は電子スピン共鳴測定において共鳴吸収を示し、吸収ピークとしてはｇ≒２．０、ｇ≒４．３及びｇ＞４．３の少なくとも３つの吸収ピークをもつものに帰属されることが知られている。（Ｊｏｕｒｎａｌ ｏｆ Ｃａｔａｌｙｓｉｓ，２４９（２００７）６７他参照）ｇ≒２．０の吸収ピークをもつものは対称四面体構造（又は高対称な多配位構造）を有する孤立鉄イオン、ｇ≒４．３及びｇ＞４．３の吸収をもつ鉄イオンは歪んだ四面体構造及び歪んだ多配位構造を有する孤立鉄イオンに帰属される。 Paramagnetic iron ion (Fe 3+ ) exhibits resonance absorption in electron spin resonance measurement, and has absorption peaks having at least three absorption peaks of g≈2.0, g≈4.3, and g> 4.3. It is known to belong to (See Journal of Catalysis, 249 (2007) 67, etc.) Those having an absorption peak of g≈2.0 are isolated iron ions having a symmetric tetrahedral structure (or highly symmetric multi-coordination structure), g≈4.3. And an iron ion having an absorption of g> 4.3 is attributed to an isolated iron ion having a distorted tetrahedral structure and a distorted multi-coordination structure.
すなわち、含有鉄の２０％以上が対称四面体構造を有する孤立鉄イオンであることは、前述の紫外可視吸光測定によって求めた孤立鉄イオンの含有率に、電子スピン共鳴測定によって求められる対称四面体構造の含有率を乗じた積によって求められる。 That is, 20% or more of the contained iron is an isolated iron ion having a symmetric tetrahedral structure, indicating that the content of the isolated iron ion determined by the above-described ultraviolet-visible absorption measurement is a symmetric tetrahedron determined by electron spin resonance measurement. It is determined by the product multiplied by the content of the structure.
電子スピン共鳴スペクトルは、微分形で表されるスペクトルで評価されることが一般的であるため、本発明においても電子スピン共鳴スペクトルの強度は、微分曲線の振幅長を用いて求められる。即ち、対称四面体構造を有する孤立鉄イオンの比率はｇ≒２．０の電子スピン共鳴スペクトルの微分曲線の振幅長を、ｇ≒２．０、ｇ≒４．３及びｇ＞４．３の各振幅長の和で除した値である。 Since the electron spin resonance spectrum is generally evaluated by a spectrum expressed in a differential form, the intensity of the electron spin resonance spectrum is also obtained in the present invention using the amplitude length of the differential curve. That is, the ratio of the isolated iron ions having a symmetric tetrahedral structure is the amplitude length of the differential curve of the electron spin resonance spectrum of g≈2.0, g≈2.0, g≈4.3, and g> 4.3. It is the value divided by the sum of each amplitude length.
本発明における電子スピン共鳴スペクトルは、一般的な方法で測定することができる。 The electron spin resonance spectrum in the present invention can be measured by a general method.
例えば電子スピン共鳴装置（（株）日本電子製ＪＥＳ−ＴＥ２００）を用い、測定条件としては測定温度７７Ｋ、マイクロ波出力は１．０ｍＷ、観測範囲は０〜１０００ｍＴ、変調幅は０．３２ｍＴ、時定数は０．３ｓｅｃとすることができる。試料は約１０ｍｇを石英製試料管に秤取し、液体窒素温度測定用デュアに挿入後、測定を行う。 For example, using an electron spin resonance apparatus (JES-TE200 manufactured by JEOL Ltd.), the measurement conditions are a measurement temperature of 77K, a microwave output of 1.0 mW, an observation range of 0 to 1000 mT, a modulation width of 0.32 mT, The constant can be 0.3 sec. About 10 mg of the sample is weighed into a quartz sample tube, inserted into a liquid nitrogen temperature measurement dewar, and then measured.
本発明において、電子スピン共鳴スペクトルの評価には、試料を乾燥空気及び／又は窒素の雰囲気下、約６００℃で焼成してフレッシュとした後、測定温度７７Ｋで測定した値を用いる。 In the present invention, the electron spin resonance spectrum is evaluated by using a value measured at a measurement temperature of 77K after the sample is baked and fresh at about 600 ° C. in an atmosphere of dry air and / or nitrogen.
本発明のβ型鉄シリケートは、ｇ≒２．０に帰属される電子スピン共鳴スペクトル（測定温度７７Ｋ）の微分吸収曲線のピーク強度が、ｇ≒４．３及びｇ＞４．３の微分吸収曲線のいずれのピーク強度より大きいものであることが特に好ましい。 The β-type iron silicate of the present invention has a differential absorption curve in which the peak intensity of the differential absorption curve of the electron spin resonance spectrum (measurement temperature 77 K) attributed to g≈2.0 is g≈4.3 and g> 4.3. It is particularly preferred that it is greater than any peak intensity of the curve.
対称四面体構造を有する孤立鉄イオンの比率は含有鉄の２０％以上、さらに３０％以上であることが好ましい。対称四面体構造を有する孤立鉄イオンの比率は理論的に１００％を超えることはない。 The ratio of isolated iron ions having a symmetric tetrahedral structure is preferably 20% or more, more preferably 30% or more of the contained iron. The ratio of isolated iron ions having a symmetric tetrahedral structure does not theoretically exceed 100%.
なお、紫外可視吸光測定において帰属される孤立鉄イオンは、鉄を別途β型鉄シリケートに担持させることによって、その絶対量を増大することができる。しかしその様な鉄イオンはそもそも結晶骨格に置換されたものではなく、大部分が対称四面体構造ではないことから、窒素酸化物の選択還元への寄与は小さい。従って本発明のβ型鉄シリケートは、紫外可視吸光測定で検出される孤立鉄イオンの比率が小さい状態で鉄含有量を増大しても高い性能は発揮されない。 In addition, the absolute amount of the isolated iron ion assigned in the UV-visible absorption measurement can be increased by separately supporting iron on β-type iron silicate. However, such iron ions are not originally replaced by a crystal skeleton, and most of them do not have a symmetric tetrahedral structure, so that the contribution to selective reduction of nitrogen oxides is small. Accordingly, the β-type iron silicate of the present invention does not exhibit high performance even when the iron content is increased in a state where the ratio of isolated iron ions detected by ultraviolet-visible absorption measurement is small.
本発明のβ型鉄シリケートはアルミニウムを構造中に含む鉄アルミノシリケートであってもよく、そのような鉄アルミノシリケートの好ましいＳｉＯ２／Ａｌ２Ｏ３モル比は特に限定はないが、耐久性（特に耐久後における低温触媒活性）の観点からＳｉＯ２／Ａｌ２Ｏ３モル比は大きい方が好ましい。ＳｉＯ２／Ａｌ２Ｏ３モル比は鉄イオンが本発明の範囲で導入されている限りにおいて４０以上、さらに７０以上が好ましい。 The β-type iron silicate of the present invention may be an iron aluminosilicate containing aluminum in the structure, and the preferred SiO 2 / Al 2 O 3 molar ratio of such an iron aluminosilicate is not particularly limited, but durability ( In particular, it is preferable that the SiO 2 / Al 2 O 3 molar ratio is large from the viewpoint of low temperature catalytic activity after durability. The SiO 2 / Al 2 O 3 molar ratio is preferably 40 or more and more preferably 70 or more as long as iron ions are introduced within the scope of the present invention.
本発明のβ型鉄シリケートは耐久処理後も高い窒素酸化物の還元性能を有するものであるが、耐久処理後においてもβ型鉄シリケート中に存在する対称四面体構造の孤立鉄イオンの比率が高いものである。 Although the β-type iron silicate of the present invention has a high nitrogen oxide reduction performance even after the endurance treatment, the ratio of isolated iron ions having a symmetric tetrahedral structure existing in the β-type iron silicate after the endurance treatment is high. It is expensive.
本発明のβ型鉄シリケート中の孤立鉄イオンの比率は耐久処理後も含有鉄に対し５０％以上が好ましく、特に６０％以上、さらに７０％以上であることが好ましい。 The ratio of isolated iron ions in the β-type iron silicate of the present invention is preferably 50% or more, particularly 60% or more, and more preferably 70% or more, with respect to the contained iron even after endurance treatment.
なお、ここで言う「耐久処理」とは、シリケート触媒の水熱耐久性を評価するために慣用される処理であって、Ｈ２Ｏを含む高温雰囲気中で行う熱処理を指す。耐久処理は、例えば、シリケート触媒を反応管に充填し、７００℃で２０時間、Ｈ２Ｏを含む空気を流通させて行う。具体的な処理条件は、実施例に記載されている。本発明のβ型鉄シリケート触媒は、高い水熱耐久性を有し、耐久処理後も高い窒素酸化物浄化活性を維持する。 The “endurance treatment” referred to here is a treatment commonly used for evaluating the hydrothermal durability of the silicate catalyst, and refers to a heat treatment performed in a high-temperature atmosphere containing H 2 O. The durability treatment is performed, for example, by filling a reaction tube with a silicate catalyst and circulating air containing H 2 O at 700 ° C. for 20 hours. Specific processing conditions are described in the examples. The β-type iron silicate catalyst of the present invention has high hydrothermal durability and maintains high nitrogen oxide purification activity even after durability treatment.
本発明のβ型鉄シリケート中の対称四面体構造を有する孤立鉄イオンの比率は耐久処理後も１５％を超えるものであり、特に２０％以上が維持されているものが好ましい。 The ratio of isolated iron ions having a symmetric tetrahedral structure in the β-type iron silicate of the present invention is more than 15% even after the endurance treatment, and particularly preferably 20% or more is maintained.
次に本願発明のβ型鉄シリケートの製造方法について説明する。 Next, a method for producing the β-type iron silicate of the present invention will be described.
本発明のβ型鉄シリケートは、高分散で、なおかつ高対称な四面体構造を有するＦｅ３＋を十分に鉄シリケート骨格中に導入することによって製造される。その様な高分散の骨格中の鉄は、シリケート骨格中に導入する鉄のモル比によって制御される。 The β-type iron silicate of the present invention is produced by fully introducing Fe 3+ having a highly dispersed and highly symmetric tetrahedral structure into the iron silicate skeleton. The iron in such a highly dispersed skeleton is controlled by the molar ratio of iron introduced into the silicate skeleton.
鉄の含有量が多すぎると、フレッシュ焼成や耐久処理によって凝集が進み易く、孤立した対称四面体構造の鉄イオンの導入が十分でなく、またβ型鉄シリケートの結晶性も低下し易い。 If the iron content is too high, aggregation is likely to proceed due to fresh baking or durability treatment, and the introduction of iron ions having an isolated symmetrical tetrahedral structure is not sufficient, and the crystallinity of β-type iron silicate tends to be lowered.
合成用原料はシリカ源、鉄源、ＳＤＡ剤、及び水から構成され、必要に応じてアルミニウム源及びフッ素源が使用される。 The raw material for synthesis is composed of a silica source, an iron source, an SDA agent, and water, and an aluminum source and a fluorine source are used as necessary.
シリカ源としてはコロイダルシリカ、無定型シリカ、珪酸ナトリウム、テトラエチルオルトシリケート、アルミノシリケートゲルなどを用いることができる。鉄源としては硝酸鉄、塩化鉄、硫酸鉄、金属鉄などを用いることができる。これらの原料は、他の成分と十分均一に混合できる形態のものが好ましい。 As the silica source, colloidal silica, amorphous silica, sodium silicate, tetraethylorthosilicate, aluminosilicate gel and the like can be used. As the iron source, iron nitrate, iron chloride, iron sulfate, metallic iron and the like can be used. These raw materials are preferably in a form that can be sufficiently uniformly mixed with other components.
ＳＤＡ原料としては、テトラエチルアンモニウムカチオンを有するテトラエチルアンモニウムヒドロキシド、テトラエチルアンモニウムブロマイド、テトラエチルアンモニウムフルオリド、更にはオクタメチレンビスキヌクリジウム、α，α’−ジキヌクリジウム−ｐ−キシレン、α，α’−ジキヌクリジウム−ｍ−キシレン、α，α’−ジキヌクリジウム−ｏ−キシレン、１，４−ジアザビシクロ［２，２，２］オクタン、１，３，３，Ｎ，Ｎ−ペンタメチル−６−アゾニウムビシクロ［３，２，１］オクタン又はＮ，Ｎ−ジエチル−１，３，３−トリメチル−６−アゾニウムビシクロ［３，２，１］オクタンカチオンを含む化合物の群の少なくとも一種以上を使用することができる。 SDA raw materials include tetraethylammonium hydroxide having tetraethylammonium cation, tetraethylammonium bromide, tetraethylammonium fluoride, octamethylenebiskinucridium, α, α′-diquinuclidium-p-xylene, α, α′-diquinuclidium -M-xylene, α, α'-diquinuclidium-o-xylene, 1,4-diazabicyclo [2,2,2] octane, 1,3,3, N, N-pentamethyl-6-azonium bicyclo [3, 2,1] octane or at least one of a group of compounds containing N, N-diethyl-1,3,3-trimethyl-6-azonium bicyclo [3,2,1] octane cation can be used.
アルミニウム源としては硫酸アルミニウム、アルミン酸ナトリウム、水酸化アルミニウム、硝酸アルミニウム、アルミノシリケートゲル、金属アルミニウムなどを用いることができ、フッ素源としてはフッ酸、フッ化ナトリウム、フッ化カリウム、フッ化アンモニウム、テトラエチルアンモニウムフルオリドなどを用いることができる。これらは他の成分と十分均一に混合できる形態のものが望ましい。 As the aluminum source, aluminum sulfate, sodium aluminate, aluminum hydroxide, aluminum nitrate, aluminosilicate gel, metal aluminum, etc. can be used. As the fluorine source, hydrofluoric acid, sodium fluoride, potassium fluoride, ammonium fluoride, Tetraethylammonium fluoride or the like can be used. These are preferably in a form that can be sufficiently uniformly mixed with other components.
原料混合物の仕込み組成は下記の組成範囲が例示される。但しこれらの組成範囲は限定的なものではなく、最終的な生成物組成が本発明のβ型鉄シリケートの組成の範囲内となるように任意に設定することができる。また、種晶などの結晶化促進作用を有する成分を添加してもよく、大きな結晶粒径が得られる条件が好ましい。 The following composition range is illustrated as a preparation composition of a raw material mixture. However, these composition ranges are not limited, and can be arbitrarily set so that the final product composition falls within the composition range of the β-type iron silicate of the present invention. In addition, a component having a crystallization promoting action such as a seed crystal may be added, and conditions under which a large crystal grain size can be obtained are preferable.
ＳｉＯ２／Ａｌ２Ｏ３モル比 １５〜３００００、好ましくは３０〜１００
ＳｉＯ２／Ｆｅ２Ｏ３モル比 ２０〜３００、好ましくは１００以下
Ｈ２Ｏ／ＳｉＯ２モル比 ５〜５０、好ましくは５〜１０
ＳＤＡ／ＳｉＯ２モル比 ０．１〜５、好ましくは０．１〜１
Ｆ／ＳｉＯ２モル比 ０〜５、好ましくは０〜１
水、シリカ源、鉄源、ＳＤＡ、必要に応じてアルミニウム源及びフッ素源の原料混合物を密閉式圧力容器中で、１００〜１８０℃の温度で、結晶化させることにより本発明に係るβ型鉄シリケートを得ることができる。
SiO 2 / Al 2 O 3 molar ratio 15 to 30000, preferably 30 to 100
SiO 2 / Fe 2 O 3 molar ratio 20 to 300, preferably 100 or less H 2 O / SiO 2 molar ratio 5 to 50, preferably 5 to 10
SDA / SiO 2 molar ratio of 0.1 to 5, preferably 0.1 to 1
F / SiO 2 molar ratio 0-5, preferably 0-1
Β-type iron according to the present invention by crystallizing a raw material mixture of water, silica source, iron source, SDA, and optionally an aluminum source and a fluorine source in a sealed pressure vessel at a temperature of 100 to 180 ° C. A silicate can be obtained.
結晶化の際、原料混合物は混合攪拌された状態でもよいし、静置した状態でもよいが、特に静置が好ましい。結晶化終了後、十分放冷し、固液分離、十分量の純水で洗浄し、１１０〜１５０℃の温度で乾燥して本発明に係るβ型鉄シリケートが得られる。 At the time of crystallization, the raw material mixture may be mixed and stirred, or may be left standing, but standing is particularly preferable. After completion of crystallization, the mixture is allowed to cool, solid-liquid separation, washed with a sufficient amount of pure water, and dried at a temperature of 110 to 150 ° C. to obtain the β-type iron silicate according to the present invention.
本発明のβ型鉄シリケートを得るためには、特にβ型鉄シリケートの結晶粒径（ＳＥＭ粒径）が大きい方が好ましい。ＳＥＭ粒径としては５μｍを超えるもの、好ましくは７μｍ以上、特に１０μｍ以上が好ましい。結晶粒径の大きいものは、結晶化を無攪拌で行うことによって得られやすい。 In order to obtain the β-type iron silicate of the present invention, it is particularly preferable that the β-type iron silicate has a larger crystal grain size (SEM particle size). The SEM particle size is more than 5 μm, preferably 7 μm or more, particularly preferably 10 μm or more. A large crystal grain size is easily obtained by performing crystallization without stirring.
本発明のβ型鉄シリケート中には活性な孤立鉄イオンが含まれているため、そのまま窒素酸化物の浄化触媒として用いることができるが、合成直後のβ型鉄シリケートは細孔内にＳＤＡを含有するため、必要に応じてこれらを除去した後に窒素酸化物の浄化触媒として使用することが好ましい。 Since the β-type iron silicate of the present invention contains active isolated iron ions, it can be used as it is as a purification catalyst for nitrogen oxides, but the β-type iron silicate immediately after synthesis contains SDA in the pores. Since it contains, after removing these as needed, it is preferable to use as a purification catalyst of nitrogen oxides.
ＳＤＡの除去処理は、酸性溶液やＳＤＡ分解成分を含んだ薬液を用いた液相処理、レジンなどを用いた交換処理、熱分解処理を採用することができる。これらの処理を組合せても良い。更には、β型鉄シリケートのイオン交換能を利用してＨ型やＮＨ４型に変換して用いることもできる。 For the SDA removal treatment, a liquid phase treatment using a chemical solution containing an acidic solution or an SDA decomposition component, an exchange treatment using a resin or the like, or a thermal decomposition treatment can be employed. These processes may be combined. Furthermore, it can be used by converting into β-type or NH 4 type by utilizing the ion exchange ability of β-type iron silicate.
本発明のβ型鉄シリケートに、さらに触媒活性な金属種を担持させて用いてもよい。 The β-type iron silicate of the present invention may be used by further supporting a catalytically active metal species.
担持させる金属種は特に限定されないが、例えば８、９、１０族、１１族の元素、特に鉄、コバルト、パラジウム、イリジウム、白金、銅、銀、金の群から選ばれる一種以上である。特に、鉄、パラジウム、白金、銅、銀の一種以上であることが好ましい。
The metal species to be supported is not particularly limited, but is, for example, at least one selected from the group consisting of elements of
また希土類金属、チタン、ジルコニアなどの助触媒成分を付加的に加えることもできる。触媒活性な金属種を担持させる場合の担持方法は特に限定されない。担持方法として、イオン交換法、含浸担持法、蒸発乾固法、沈殿担持法、物理混合法等の方法が採用することができる。金属担持に用いる原料としては、硝酸塩、硫酸塩、酢酸塩、塩化物、錯塩、酸化物、複合酸化物などがいずれも使用できる。 In addition, a promoter component such as rare earth metal, titanium or zirconia can be additionally added. There are no particular limitations on the loading method when loading a catalytically active metal species. As the loading method, methods such as an ion exchange method, an impregnation loading method, an evaporation to dryness method, a precipitation loading method, and a physical mixing method can be employed. Nitrate, sulfate, acetate, chloride, complex salt, oxide, composite oxide and the like can be used as raw materials for metal loading.
金属の担持量は限定されないが、特に０．１〜１０重量％の範囲が好ましい。 The amount of metal supported is not limited, but a range of 0.1 to 10% by weight is particularly preferable.
本発明の触媒は、シリカ、アルミナ及び粘土鉱物等のバインダーと混合し成形して使用することもできる。成形する際に用いられる粘土鉱物として、カオリン、アタパルガイト、モンモリロナイト、ベントナイト、アロフェン、セピオライトが例示できる。また、コージェライト製或いは金属製のハニカム基材にウォッシュコートして使用することもできる。 The catalyst of the present invention can be used after being mixed with a binder such as silica, alumina and clay mineral. Examples of clay minerals used for molding include kaolin, attapulgite, montmorillonite, bentonite, allophane, and sepiolite. Moreover, it can also be used by wash-coating on a cordierite or metal honeycomb substrate.
本発明のβ型鉄シリケートを窒素酸化物浄化触媒として用い、還元剤としてアンモニア、尿素、有機アミン類の少なくとも一つを反応させることによって、排ガス中の窒素酸化
物を選択的に還元することができる。
By using β-type iron silicate of the present invention as a nitrogen oxide purification catalyst and reacting at least one of ammonia, urea, and organic amines as a reducing agent, nitrogen oxide in exhaust gas can be selectively reduced. it can.
本発明で浄化される窒素酸化物は、一酸化窒素、二酸化窒素及びそれらの混合物である。ここで本発明により処理される排ガス中の窒素酸化物濃度は限定されるものではない。 The nitrogen oxides purified by the present invention are nitric oxide, nitrogen dioxide and mixtures thereof. Here, the nitrogen oxide concentration in the exhaust gas treated according to the present invention is not limited.
還元剤の添加方法は特に限定されず、還元成分をガス状で直接添加する方法、水溶液などの液状を噴霧し気化させる方法、噴霧熱分解させる方法等を採用することができる。これらの還元剤の添加量は、十分に窒素酸化物が浄化できるように任意に設定することができる。 The method of adding the reducing agent is not particularly limited, and a method of directly adding the reducing component in a gaseous state, a method of spraying and vaporizing a liquid such as an aqueous solution, a method of spraying pyrolysis, and the like can be employed. The addition amount of these reducing agents can be arbitrarily set so that nitrogen oxides can be sufficiently purified.
また該排ガスには窒素酸化物以外の成分が含まれていてもよく、例えば炭化水素、一酸化炭素、二酸化炭素、水素、窒素、酸素、硫黄酸化物、水が含まれていても良い。具体的には、本発明の方法ではディーゼル自動車、ガソリン自動車、ボイラー、ガスタービン等の多種多様の排ガスから窒素酸化物を浄化することができる。 The exhaust gas may contain components other than nitrogen oxides, and may contain, for example, hydrocarbons, carbon monoxide, carbon dioxide, hydrogen, nitrogen, oxygen, sulfur oxides, and water. Specifically, the method of the present invention can purify nitrogen oxides from a wide variety of exhaust gases such as diesel vehicles, gasoline vehicles, boilers, gas turbines and the like.
本発明の窒素酸化物の浄化方法において、本発明のβ型鉄シリケートから成る触媒と排ガスを接触させる際の空間速度は特に限定されないが、好ましい空間速度は体積基準で５００〜５０万ｈｒ−１、更に好ましくは２，０００〜３０万ｈｒ−１である。 In the method for purifying nitrogen oxides of the present invention, the space velocity when contacting the exhaust gas with the catalyst comprising the β-type iron silicate of the present invention is not particularly limited, but the preferred space velocity is 500 to 500,000 hr −1 on a volume basis. More preferably, it is 2,000 to 300,000 hr −1 .
本発明のβ型鉄シリケートは窒素酸化物の浄化性能が高く、幅広い温度域、特に２５０℃以下の比較的低温の領域において効率的に窒素酸化物を浄化することができる。また耐久性に優れ、耐久処理後も従来品より高い触媒活性を有する。 The β-type iron silicate of the present invention has high nitrogen oxide purification performance, and can efficiently purify nitrogen oxide in a wide temperature range, particularly in a relatively low temperature range of 250 ° C. or lower. Moreover, it has excellent durability and has higher catalytic activity than conventional products even after endurance treatment.
以下本発明を実施例で説明するが、本発明はこれらの実施例に限定されるものではない。 EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.
（紫外可視吸光測定）
紫外可視吸光測定は以下の条件で行った。
(UV-visible absorption measurement)
The ultraviolet-visible absorption measurement was performed under the following conditions.
積分球付属装置：：（株）島津製作所製のＩＳＲ−３１００
自記分光光度計：（株）島津製作所製のＵＶ−３１００
スキャンスピード：２００ｎｍ／ｍｉｎ
スリット幅：５．０ｎｍ
ベースライン補正：硫酸バリウム粉末使用
波長範囲：２２０〜７００ｎｍの反射率測定
試料前処理：乾燥空気中 ６００℃焼成（フレッシュ焼成）
（電子スピン共鳴測定）
電子スピン共鳴測定を以下の条件で行った。
Integrating sphere attachment device :: ISR-3100 manufactured by Shimadzu Corporation
Self-recording spectrophotometer: UV-3100 manufactured by Shimadzu Corporation
Scan speed: 200 nm / min
Slit width: 5.0nm
Baseline correction: Barium sulfate powder used Wavelength range: 220-700 nm reflectance measurement Sample pretreatment: 600 ° C. firing in dry air (fresh firing)
(Electron spin resonance measurement)
Electron spin resonance measurement was performed under the following conditions.
測定温度：７７Ｋ
マイクロ波出力：１．０ｍＷ
観測範囲：０〜１０００ｍＴ
変調幅：０．３２ｍＴ
時定数：０．３ｓｅｃ
試料量：約１０ｍｇ
（窒素酸化物浄化試験）
実施例、比較例で合成した鉄シリケート粉末をプレス成形後、破砕して１２〜２０メッシュに整粒した。整粒した粉末１．５ｃｃを常圧固定床流通式反応管に充填した。触媒層に、下記表２に示す組成を有するガスを１５００ｃｃ／ｍｉｎで流通させながら、１００〜５００℃の任意の温度で定常的な窒素酸化物の除去率を測定した。
Measurement temperature: 77K
Microwave output: 1.0 mW
Observation range: 0 to 1000 mT
Modulation width: 0.32 mT
Time constant: 0.3 sec
Sample amount: about 10mg
(Nitrogen oxide purification test)
The iron silicate powders synthesized in Examples and Comparative Examples were pressed and then crushed and sized to 12-20 mesh. 1.5 cc of the sized powder was filled into a normal pressure fixed bed flow type reaction tube. While the gas having the composition shown in Table 2 below was passed through the catalyst layer at 1500 cc / min, the nitrogen oxide removal rate at a constant temperature of 100 to 500 ° C. was measured.
耐久処理後の性能は、各触媒３ｃｃを常圧固定床流通式反応管に充填し、７００℃で２０時間、Ｈ２Ｏ＝１０ｖｏｌ％を含む空気を３００ｃｃ／ｍｉｎで流通させて処理した後、上記と同様の条件で窒素酸化物の除去率を測定した。 The performance after the endurance treatment was as follows: 3 cc of each catalyst was filled in a normal pressure fixed bed flow type reaction tube, and the air containing H 2 O = 10 vol% was circulated at 300 cc / min for 20 hours at 700 ° C. The nitrogen oxide removal rate was measured under the same conditions as above.
実施例１
水酸化テトラエチルアンモニウム３５％水溶液（以下、「ＴＥＡＯＨ」と呼称する）２５７ｇに、硝酸アルミニウム九水和物１８．７９ｇ、硝酸鉄九水和物４．６３ｇを溶解し、テトラエチルオルトシリケート（ＴＥＯＳ）２０９ｇを加え、十分に撹拌混合し室温にて加水分解を行い、生成したエタノールを蒸発させた。続いて必要量の水を蒸発させた。これに４８％フッ酸２０．８８ｇを加え、乳鉢にて混合した後、この反応混合物をステンレス製オートクレーブに充填し、１５０℃で２４０時間加熱して結晶化した。反応混合物の組成は４０ＳｉＯ２：Ａｌ２Ｏ３：０．２３Ｆｅ２Ｏ３：２０ＨＦ：２４．４ＴＥＡＯＨ：３００Ｈ２Ｏであった。結晶化後のスラリー状混合物は白色であった。これを固液分離し、純水で洗浄し、１１０℃で乾燥した。
Example 1
In 257 g of a 35% aqueous solution of tetraethylammonium hydroxide (hereinafter referred to as “TEAOH”), 18.79 g of aluminum nitrate nonahydrate and 4.63 g of iron nitrate nonahydrate are dissolved, and 209 g of tetraethylorthosilicate (TEOS) is obtained. The mixture was thoroughly stirred and mixed, hydrolyzed at room temperature, and the produced ethanol was evaporated. Subsequently, the required amount of water was evaporated. To this, 20.88 g of 48% hydrofluoric acid was added and mixed in a mortar, and then the reaction mixture was filled in a stainless steel autoclave and crystallized by heating at 150 ° C. for 240 hours. The composition of the reaction mixture is 40SiO 2: Al 2 O 3: 0.23Fe 2 O 3: 20HF: 24.4TEAOH: was 300H 2 O. The slurry mixture after crystallization was white. This was separated into solid and liquid, washed with pure water, and dried at 110 ° C.
その乾燥粉末を空気流通下、６００℃で２時間焼成した。得られたβ型鉄シリケートのＸ線回折測定の結果、表１に示すＸ線回折パターンが得られた。ＩＣＰ発光分析の結果、ＳｉＯ２／Ａｌ２Ｏ３モル比は４１、ＳｉＯ２／Ｆｅ２Ｏ３モル比は１６６であった。結晶粒径は約１０μｍであった。 The dried powder was calcined at 600 ° C. for 2 hours under air flow. As a result of X-ray diffraction measurement of the obtained β-type iron silicate, the X-ray diffraction patterns shown in Table 1 were obtained. As a result of ICP emission analysis, the SiO 2 / Al 2 O 3 molar ratio was 41, and the SiO 2 / Fe 2 O 3 molar ratio was 166. The crystal grain size was about 10 μm.
実施例２
結晶化させる反応混合物の組成比を７０ＳｉＯ２：Ａｌ２Ｏ３：０．４７Ｆｅ２Ｏ３：３５ＨＦ：４２ＴＥＡＯＨ：４９０Ｈ２Ｏに変えたこと以外は実施例１と同様の操作で反応混合物を調製した。この反応混合物をステンレス製オートクレーブに充填し、１５０℃で１６０時間加熱して結晶化した。結晶化後のスラリー状混合物は白色であった。これを固液分離し、十分量の純水で洗浄し、１１０℃で乾燥した。その乾燥粉末を空気流通下、６００℃で２時間焼成した。
Example 2
A reaction mixture was prepared in the same manner as in Example 1 except that the composition ratio of the reaction mixture to be crystallized was changed to 70SiO 2 : Al 2 O 3 : 0.47Fe 2 O 3 : 35HF: 42TEAOH: 490H 2 O. . The reaction mixture was filled in a stainless steel autoclave and crystallized by heating at 150 ° C. for 160 hours. The slurry mixture after crystallization was white. This was separated into solid and liquid, washed with a sufficient amount of pure water, and dried at 110 ° C. The dried powder was calcined at 600 ° C. for 2 hours under air flow.
得られたβ型鉄シリケートのＸ線回折測定の結果、表１に示すＸ線回折パターンが得られた。 As a result of X-ray diffraction measurement of the obtained β-type iron silicate, the X-ray diffraction patterns shown in Table 1 were obtained.
実施例３
結晶化させる反応混合物の組成比を７０ＳｉＯ２：Ａｌ２Ｏ３：Ｆｅ２Ｏ３：３５ＨＦ：４２ＴＥＡＯＨ：４９０Ｈ２Ｏに変えたこと以外は実施例１と同様の操作で反応混合物を調製した。この反応混合物をステンレス製オートクレーブに充填し、１５０℃で２４０時間加熱して結晶化した。結晶化後のスラリー状混合物は白色であった。これを固液分離し、十分量の純水で洗浄し、１１０℃で乾燥した。その乾燥粉末を空気流通下、６００℃で２時間焼成した。
Example 3
A reaction mixture was prepared in the same manner as in Example 1, except that the composition ratio of the reaction mixture to be crystallized was changed to 70SiO 2 : Al 2 O 3 : Fe 2 O 3 : 35HF: 42TEAOH: 490H 2 O. This reaction mixture was charged in a stainless steel autoclave and crystallized by heating at 150 ° C. for 240 hours. The slurry mixture after crystallization was white. This was separated into solid and liquid, washed with a sufficient amount of pure water, and dried at 110 ° C. The dried powder was calcined at 600 ° C. for 2 hours under air flow.
得られたβ型鉄シリケートのＸ線回折測定の結果、表１に示すＸ線回折パターンが得られた。 As a result of X-ray diffraction measurement of the obtained β-type iron silicate, the X-ray diffraction patterns shown in Table 1 were obtained.
比較例１
ＳｉＯ２／Ａｌ２Ｏ３モル比が４０の東ソー製β型ゼオライト（商品名：ＨＳＺ−９４０ＮＨＡ）を乾燥空気気流下、６００℃で焼成した。Ｘ線回折測定の結果、β型ゼオライトは表１のＸ線回折パターンを有し、ＩＣＰ発光分析の結果、ＳｉＯ２／Ａｌ２Ｏ３モル比は４０であった。このβ型ゼオライトに鉄担持量が３重量％になるように精秤されたＦｅ（ＮＯ３）３・９水和物の水溶液を用いて、鉄を含浸担持した。これを５００℃で空気焼成した。
Comparative Example 1
Tosoh β-type zeolite (trade name: HSZ-940NHA) having a SiO 2 / Al 2 O 3 molar ratio of 40 was calcined at 600 ° C. in a dry air stream. As a result of X-ray diffraction measurement, β-type zeolite had the X-ray diffraction pattern shown in Table 1. As a result of ICP emission analysis, the SiO 2 / Al 2 O 3 molar ratio was 40. The β-type zeolite supporting iron amount is accurately weighed so as to be 3 wt% Fe (NO 3) 3 · 9 with an aqueous solution of hydrate was impregnated supporting iron. This was air calcined at 500 ° C.
鉄の含浸処理によって合計の鉄含有量は多いが、紫外可視吸光測定による孤立鉄イオンの含有率は３８％であり、凝集鉄の多いものであった。 Although the total iron content was large due to the impregnation treatment with iron, the content of isolated iron ions by ultraviolet-visible absorption measurement was 38%, which was high in agglomerated iron.
比較例２
ＴＥＡＯＨ２３５ｇに、水酸化アルミニウム１．２６ｇ、硝酸鉄８．３６ｇ、東ソーシリカ製の無定形シリカ粉末（商品名：ニップシールＶＮ−３）６２．８ｇおよび水１７２ｇを加え、十分に撹拌混合した。反応混合物の組成は９０ＳｉＯ２：Ａｌ２Ｏ３：Ｆｅ２Ｏ３：５４ＴＥＡＯＨ：１８００Ｈ２Ｏであった。この反応混合物をステンレス製オートクレーブに密閉し、１５０℃で９６時間加熱して結晶化した。結晶化後のスラリー状混合物は白色であった。これを固液分離し、十分量の純水で洗浄し、１１０℃で乾燥した。その乾燥粉末を空気流通下、６００℃で焼成し、β型鉄シリケートを得た。
Comparative Example 2
To 235 g of TEAOH, 1.26 g of aluminum hydroxide, 8.36 g of iron nitrate, 62.8 g of amorphous silica powder (trade name: Nipsil VN-3) manufactured by Tosoh Silica, and 172 g of water were added and mixed thoroughly. The composition of the reaction mixture was 90SiO 2 : Al 2 O 3 : Fe 2 O 3 : 54TEAOH: 1800H 2 O. The reaction mixture was sealed in a stainless steel autoclave and heated at 150 ° C. for 96 hours for crystallization. The slurry mixture after crystallization was white. This was separated into solid and liquid, washed with a sufficient amount of pure water, and dried at 110 ° C. The dried powder was fired at 600 ° C. under air flow to obtain β-type iron silicate.
Ｘ線回折測定の結果、β型鉄シリケートは表１のＸ線回折パターンを有していたが、紫外可視吸光測定から求めた孤立鉄イオンの含有率は７８％であった。 As a result of the X-ray diffraction measurement, the β-type iron silicate had the X-ray diffraction pattern shown in Table 1, but the content of isolated iron ions determined from the ultraviolet-visible absorption measurement was 78%.
実施例、比較例で得られた触媒の耐久処理前後の窒素酸化物浄化性能を評価した結果を表３（耐久処理前；フレッシュ）及び表４（耐久処理後）に示す。耐久処理前および耐久処理後の触媒について、紫外可視吸光測定による孤立鉄イオンの比率、電子スピン共鳴測定による対称四面体構造の比率と、耐久処理後の低温（２５０℃以下）での窒素酸化物の浄化性能の関係を求めた結果を表５（耐久処理前；フレッシュ）及び表６（耐久処理後）に示す。 Table 3 (before endurance treatment; fresh) and Table 4 (after endurance treatment) show the results of evaluating the nitrogen oxide purification performance before and after the endurance treatment of the catalysts obtained in Examples and Comparative Examples. For catalysts before and after endurance treatment, the ratio of isolated iron ions by UV-visible absorption measurement, the ratio of symmetric tetrahedral structure by electron spin resonance measurement, and nitrogen oxides at low temperature (250 ° C or lower) after endurance treatment Table 5 (before endurance treatment; fresh) and Table 6 (after endurance treatment) show the results of determining the relationship between the purification performances.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008309424A JP5169779B2 (en) | 2007-12-18 | 2008-12-04 | Nitrogen oxide purification catalyst and nitrogen oxide purification method |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007325757 | 2007-12-18 | ||
| JP2007325757 | 2007-12-18 | ||
| JP2008309424A JP5169779B2 (en) | 2007-12-18 | 2008-12-04 | Nitrogen oxide purification catalyst and nitrogen oxide purification method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2009166031A JP2009166031A (en) | 2009-07-30 |
| JP5169779B2 true JP5169779B2 (en) | 2013-03-27 |
Family
ID=40802984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2008309424A Active JP5169779B2 (en) | 2007-12-18 | 2008-12-04 | Nitrogen oxide purification catalyst and nitrogen oxide purification method |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP5169779B2 (en) |
| CN (1) | CN101462054A (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2475740B (en) * | 2009-11-30 | 2017-06-07 | Johnson Matthey Plc | Catalysts for treating transient NOx emissions |
| US9675935B2 (en) | 2009-12-22 | 2017-06-13 | Tosoh Corporation | Metallosilicates, processes for producing the same, nitrogen oxide removal catalyst, process for producing the same, and method for removing nitrogen oxide with the same |
| JP5594121B2 (en) * | 2009-12-22 | 2014-09-24 | 東ソー株式会社 | Novel metallosilicate and nitrogen oxide purification catalyst |
| JP5966263B2 (en) * | 2011-06-30 | 2016-08-10 | いすゞ自動車株式会社 | Diesel engine exhaust gas purification device and purification method |
| JP5821540B2 (en) * | 2011-11-07 | 2015-11-24 | いすゞ自動車株式会社 | Method for producing urea SCR catalyst |
| JP5970927B2 (en) * | 2012-04-05 | 2016-08-17 | いすゞ自動車株式会社 | Method for producing urea SCR catalyst |
| CN105251342A (en) * | 2015-11-13 | 2016-01-20 | 无锡桥阳机械制造有限公司 | Air conditioner filter for preventing and treating haze |
| CN105289285A (en) * | 2015-11-13 | 2016-02-03 | 无锡桥阳机械制造有限公司 | Fan with purifying function |
| CN105457485A (en) * | 2015-11-13 | 2016-04-06 | 无锡桥阳机械制造有限公司 | Method for purifying indoor air by fan |
| CN105402833A (en) * | 2015-11-13 | 2016-03-16 | 无锡桥阳机械制造有限公司 | Air purifying method for building with central air conditioner |
| CN105249561A (en) * | 2015-11-13 | 2016-01-20 | 无锡桥阳机械制造有限公司 | Mask for preventing and treating haze |
| CN105344178A (en) * | 2015-11-14 | 2016-02-24 | 华玉叶 | Method for purification of indoor air by household radiator |
| CN105457412A (en) * | 2015-11-14 | 2016-04-06 | 华玉叶 | Household stove flue gas purification method |
| CN105289155A (en) * | 2015-11-14 | 2016-02-03 | 华玉叶 | Method for purifying household coal stove flue gas |
| CN105298936A (en) * | 2015-11-14 | 2016-02-03 | 无锡清杨机械制造有限公司 | Bathroom exhaust fan with purifying function |
| CN105258184A (en) * | 2015-11-14 | 2016-01-20 | 无锡清杨机械制造有限公司 | Smoke exhaust ventilator capable of purifying air |
| CN109681299B (en) * | 2019-01-23 | 2021-01-15 | 黄冈师范学院 | Engine control method of Urea-SCR system of diesel engine |
| CN113845201B (en) * | 2021-10-13 | 2023-05-26 | 蚌埠学院 | Si-Fe/gamma-Al 2 O 3 Application of catalyst in degradation of phenol-containing wastewater |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1182796A (en) * | 1981-04-02 | 1985-02-19 | Charles J. Plank | Highly siliceous porous crystalline material, method of preparing same and catalytic conversion therewith |
| JP3839565B2 (en) * | 1997-01-20 | 2006-11-01 | 日本碍子株式会社 | Synthesis method of high silica silicate molecular sieve |
| JP4867065B2 (en) * | 2000-11-20 | 2012-02-01 | 東ソー株式会社 | Method for producing novel BEA type metalloaluminosilicate |
| JP4745968B2 (en) * | 2004-07-29 | 2011-08-10 | エヌ・イーケムキャット株式会社 | Denitration catalyst with excellent low temperature characteristics |
| JP4957176B2 (en) * | 2006-10-24 | 2012-06-20 | 東ソー株式会社 | Nitrogen oxide purification catalyst and nitrogen oxide purification method |
-
2008
- 2008-04-28 CN CN 200810131487 patent/CN101462054A/en active Pending
- 2008-12-04 JP JP2008309424A patent/JP5169779B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2009166031A (en) | 2009-07-30 |
| CN101462054A (en) | 2009-06-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5169779B2 (en) | Nitrogen oxide purification catalyst and nitrogen oxide purification method | |
| JP5958070B2 (en) | β-type iron silicate composition and nitrogen oxide reduction method | |
| JP5895510B2 (en) | Chabazite-type zeolite and method for producing the same, low-silica zeolite supporting copper, nitrogen oxide reduction and removal catalyst containing the zeolite, and nitrogen oxide reduction and removal method using the catalyst | |
| JP5082361B2 (en) | Β-type zeolite for SCR catalyst and method for purifying nitrogen oxides using the same | |
| JP4957176B2 (en) | Nitrogen oxide purification catalyst and nitrogen oxide purification method | |
| WO2011078149A1 (en) | Novel metallosilicate, production method thereof, nitrogen oxide purification catalyst, production method thereof, and nitrogen oxide purification method making use thereof | |
| KR101473007B1 (en) | Nitrogen oxide-reducing catalyst and method for reducing nitrogen oxide | |
| JP4992214B2 (en) | Nitrogen oxide purification catalyst comprising β-type zeolite and nitrogen oxide purification method using the same | |
| JP2014515723A (en) | Large crystals of organic chabazite and methods for making and using the same | |
| US11154846B2 (en) | Copper containing MOZ zeolite for selective NOx reduction catalysis | |
| CN109963811A (en) | Crystalline zeolite with ERI/CHA symbiosis framework types | |
| WO2021114208A1 (en) | Denitration catalyst and denitration method using the catalyst | |
| JP5309936B2 (en) | Nitrogen oxide purification catalyst and nitrogen oxide purification method | |
| JP5594121B2 (en) | Novel metallosilicate and nitrogen oxide purification catalyst | |
| JPH11216358A (en) | Hydrocarbon adsorbent and catalyst for cleaning waste gas | |
| CN107073444A (en) | Heat-staple NH3SCR catalyst composition | |
| KR20240012510A (en) | Synthesis of AFX-BEA zeolite composite catalyst containing palladium for NOX adsorption | |
| BR112021013819A2 (en) | MOLECULAR SIEVE, COMPOSITION, CALCINED ZEOLITE, CALCINED MOLECULAR SIEVE, CATALYST, CATALYST ARTICLE, AND, METHODS FOR SYNTHESISTING A MOLECULAR SIEVE, FOR TREATMENT AN EXHAUST GAS, AND FOR CONVERTING Methanol TO AN OLEFIN |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20111121 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20121122 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20121204 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20121217 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 5169779 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20160111 Year of fee payment: 3 |