JP2005087826A - Nano honeycomb catalyst and production method therefor - Google Patents
Nano honeycomb catalyst and production method therefor Download PDFInfo
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- JP2005087826A JP2005087826A JP2003322744A JP2003322744A JP2005087826A JP 2005087826 A JP2005087826 A JP 2005087826A JP 2003322744 A JP2003322744 A JP 2003322744A JP 2003322744 A JP2003322744 A JP 2003322744A JP 2005087826 A JP2005087826 A JP 2005087826A
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- Prior art keywords
- solution
- nanohoneycomb
- noble metal
- alkoxide
- metal ion
- Prior art date
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- 239000003054 catalyst Substances 0.000 title claims abstract description 104
- 238000004519 manufacturing process Methods 0.000 title claims description 14
- 229910000510 noble metal Inorganic materials 0.000 claims abstract description 129
- 239000010953 base metal Substances 0.000 claims abstract description 79
- 150000004703 alkoxides Chemical class 0.000 claims abstract description 46
- 239000002923 metal particle Substances 0.000 claims abstract description 33
- 229910021645 metal ion Inorganic materials 0.000 claims abstract description 27
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 23
- 239000000693 micelle Substances 0.000 claims description 174
- 239000000243 solution Substances 0.000 claims description 126
- 239000007864 aqueous solution Substances 0.000 claims description 42
- 150000002500 ions Chemical class 0.000 claims description 40
- -1 aluminum alkoxide Chemical class 0.000 claims description 31
- 229910052751 metal Inorganic materials 0.000 claims description 24
- 239000002184 metal Substances 0.000 claims description 23
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 22
- 229910052782 aluminium Inorganic materials 0.000 claims description 17
- 239000003638 chemical reducing agent Substances 0.000 claims description 14
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 13
- 239000000203 mixture Substances 0.000 claims description 12
- 239000011148 porous material Substances 0.000 claims description 12
- 229910052726 zirconium Inorganic materials 0.000 claims description 11
- 229910052684 Cerium Inorganic materials 0.000 claims description 10
- 229910052697 platinum Inorganic materials 0.000 claims description 9
- 229910052710 silicon Inorganic materials 0.000 claims description 9
- 239000010703 silicon Substances 0.000 claims description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 8
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 8
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 8
- 239000000084 colloidal system Substances 0.000 claims description 8
- 239000010970 precious metal Substances 0.000 claims description 8
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 7
- 239000012298 atmosphere Substances 0.000 claims description 7
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims description 7
- 239000011888 foil Substances 0.000 claims description 7
- 229910052719 titanium Inorganic materials 0.000 claims description 7
- 239000010936 titanium Substances 0.000 claims description 7
- 229910052721 tungsten Inorganic materials 0.000 claims description 6
- 239000010937 tungsten Substances 0.000 claims description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 5
- 230000008569 process Effects 0.000 claims description 5
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 4
- 229910017052 cobalt Inorganic materials 0.000 claims description 4
- 239000010941 cobalt Substances 0.000 claims description 4
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 4
- 239000011261 inert gas Substances 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 4
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 229910052763 palladium Inorganic materials 0.000 claims description 4
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 4
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 3
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims description 3
- 229910052788 barium Inorganic materials 0.000 claims description 3
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims description 3
- 229910052741 iridium Inorganic materials 0.000 claims description 3
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 claims description 3
- 239000011259 mixed solution Substances 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 3
- 229910052762 osmium Inorganic materials 0.000 claims description 3
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 claims description 3
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 claims description 3
- 239000010948 rhodium Substances 0.000 claims description 3
- 229910052703 rhodium Inorganic materials 0.000 claims description 3
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims description 3
- 229910052707 ruthenium Inorganic materials 0.000 claims description 3
- 239000012266 salt solution Substances 0.000 claims description 3
- 229910052732 germanium Inorganic materials 0.000 claims description 2
- 229910052720 vanadium Inorganic materials 0.000 claims description 2
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 claims 1
- 229910052733 gallium Inorganic materials 0.000 claims 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 claims 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims 1
- 239000002245 particle Substances 0.000 abstract description 47
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract description 8
- 239000010419 fine particle Substances 0.000 abstract description 6
- 239000004094 surface-active agent Substances 0.000 description 20
- 239000010410 layer Substances 0.000 description 15
- 239000003960 organic solvent Substances 0.000 description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 13
- 238000006243 chemical reaction Methods 0.000 description 12
- 229910045601 alloy Inorganic materials 0.000 description 11
- 239000000956 alloy Substances 0.000 description 11
- 230000003197 catalytic effect Effects 0.000 description 11
- 150000004706 metal oxides Chemical class 0.000 description 10
- 238000001035 drying Methods 0.000 description 9
- 238000010304 firing Methods 0.000 description 9
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 8
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 8
- 230000000694 effects Effects 0.000 description 8
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 7
- 150000001875 compounds Chemical class 0.000 description 7
- 239000007789 gas Substances 0.000 description 7
- 229910000000 metal hydroxide Inorganic materials 0.000 description 7
- 150000004692 metal hydroxides Chemical class 0.000 description 7
- 229910044991 metal oxide Inorganic materials 0.000 description 7
- 239000002904 solvent Substances 0.000 description 7
- 238000003756 stirring Methods 0.000 description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 6
- 238000006460 hydrolysis reaction Methods 0.000 description 6
- SMZOGRDCAXLAAR-UHFFFAOYSA-N aluminium isopropoxide Chemical compound [Al+3].CC(C)[O-].CC(C)[O-].CC(C)[O-] SMZOGRDCAXLAAR-UHFFFAOYSA-N 0.000 description 5
- 125000001165 hydrophobic group Chemical group 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 5
- 229910052755 nonmetal Inorganic materials 0.000 description 5
- 230000001376 precipitating effect Effects 0.000 description 5
- 239000012495 reaction gas Substances 0.000 description 5
- 239000002002 slurry Substances 0.000 description 5
- KBPLFHHGFOOTCA-UHFFFAOYSA-N 1-Octanol Chemical compound CCCCCCCCO KBPLFHHGFOOTCA-UHFFFAOYSA-N 0.000 description 4
- BBMCTIGTTCKYKF-UHFFFAOYSA-N 1-heptanol Chemical compound CCCCCCCO BBMCTIGTTCKYKF-UHFFFAOYSA-N 0.000 description 4
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 4
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 4
- DMEGYFMYUHOHGS-UHFFFAOYSA-N cycloheptane Chemical compound C1CCCCCC1 DMEGYFMYUHOHGS-UHFFFAOYSA-N 0.000 description 4
- DIOQZVSQGTUSAI-UHFFFAOYSA-N decane Chemical compound CCCCCCCCCC DIOQZVSQGTUSAI-UHFFFAOYSA-N 0.000 description 4
- LQZZUXJYWNFBMV-UHFFFAOYSA-N dodecan-1-ol Chemical compound CCCCCCCCCCCCO LQZZUXJYWNFBMV-UHFFFAOYSA-N 0.000 description 4
- BXWNKGSJHAJOGX-UHFFFAOYSA-N hexadecan-1-ol Chemical compound CCCCCCCCCCCCCCCCO BXWNKGSJHAJOGX-UHFFFAOYSA-N 0.000 description 4
- UAEPNZWRGJTJPN-UHFFFAOYSA-N methylcyclohexane Chemical compound CC1CCCCC1 UAEPNZWRGJTJPN-UHFFFAOYSA-N 0.000 description 4
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 4
- GSGDTSDELPUTKU-UHFFFAOYSA-N nonoxybenzene Chemical compound CCCCCCCCCOC1=CC=CC=C1 GSGDTSDELPUTKU-UHFFFAOYSA-N 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 239000012279 sodium borohydride Substances 0.000 description 4
- 229910000033 sodium borohydride Inorganic materials 0.000 description 4
- WGTYBPLFGIVFAS-UHFFFAOYSA-M tetramethylammonium hydroxide Chemical compound [OH-].C[N+](C)(C)C WGTYBPLFGIVFAS-UHFFFAOYSA-M 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 235000011114 ammonium hydroxide Nutrition 0.000 description 3
- 150000003863 ammonium salts Chemical class 0.000 description 3
- 239000012693 ceria precursor Substances 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- 239000000470 constituent Substances 0.000 description 3
- 239000000446 fuel Substances 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 230000007062 hydrolysis Effects 0.000 description 3
- 238000011068 loading method Methods 0.000 description 3
- 150000002823 nitrates Chemical class 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 238000010298 pulverizing process Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 3
- 239000011882 ultra-fine particle Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- NHTMVDHEPJAVLT-UHFFFAOYSA-N Isooctane Chemical compound CC(C)CC(C)(C)C NHTMVDHEPJAVLT-UHFFFAOYSA-N 0.000 description 2
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- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 150000001341 alkaline earth metal compounds Chemical class 0.000 description 2
- HSJPMRKMPBAUAU-UHFFFAOYSA-N cerium(3+);trinitrate Chemical compound [Ce+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O HSJPMRKMPBAUAU-UHFFFAOYSA-N 0.000 description 2
- 229960000541 cetyl alcohol Drugs 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 150000003841 chloride salts Chemical class 0.000 description 2
- 239000003426 co-catalyst Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 229910052878 cordierite Inorganic materials 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 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 2
- JVSWJIKNEAIKJW-UHFFFAOYSA-N dimethyl-hexane Natural products CCCCCC(C)C JVSWJIKNEAIKJW-UHFFFAOYSA-N 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- GYNNXHKOJHMOHS-UHFFFAOYSA-N methyl-cycloheptane Natural products CC1CCCCCC1 GYNNXHKOJHMOHS-UHFFFAOYSA-N 0.000 description 2
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- 239000000047 product Substances 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 238000006722 reduction reaction Methods 0.000 description 2
- UQMOLLPKNHFRAC-UHFFFAOYSA-N tetrabutyl silicate Chemical compound CCCCO[Si](OCCCC)(OCCCC)OCCCC UQMOLLPKNHFRAC-UHFFFAOYSA-N 0.000 description 2
- VXUYXOFXAQZZMF-UHFFFAOYSA-N titanium(IV) isopropoxide Chemical compound CC(C)O[Ti](OC(C)C)(OC(C)C)OC(C)C VXUYXOFXAQZZMF-UHFFFAOYSA-N 0.000 description 2
- SZEMGTQCPRNXEG-UHFFFAOYSA-M trimethyl(octadecyl)azanium;bromide Chemical compound [Br-].CCCCCCCCCCCCCCCCCC[N+](C)(C)C SZEMGTQCPRNXEG-UHFFFAOYSA-M 0.000 description 2
- 239000008096 xylene Substances 0.000 description 2
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical class OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 description 1
- FCYWHHAMMDGCCG-UHFFFAOYSA-N C(C)O.[O-]CC.[Al+3].[O-]CC.[O-]CC Chemical compound C(C)O.[O-]CC.[Al+3].[O-]CC.[O-]CC FCYWHHAMMDGCCG-UHFFFAOYSA-N 0.000 description 1
- PSGGLSHYPIONJR-UHFFFAOYSA-N C(CCC)O.C(CCC)[O-].[Al+3].C(CCC)[O-].C(CCC)[O-] Chemical compound C(CCC)O.C(CCC)[O-].[Al+3].C(CCC)[O-].C(CCC)[O-] PSGGLSHYPIONJR-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 229910002492 Ce(NO3)3·6H2O Inorganic materials 0.000 description 1
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
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- BDAGIHXWWSANSR-UHFFFAOYSA-M Formate Chemical compound [O-]C=O BDAGIHXWWSANSR-UHFFFAOYSA-M 0.000 description 1
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- VBIIFPGSPJYLRR-UHFFFAOYSA-M Stearyltrimethylammonium chloride Chemical compound [Cl-].CCCCCCCCCCCCCCCCCC[N+](C)(C)C VBIIFPGSPJYLRR-UHFFFAOYSA-M 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 229910006219 ZrO(NO3)2·2H2O Inorganic materials 0.000 description 1
- GWBCIGVMZFHCLA-UHFFFAOYSA-N [Ce+4].CC[O-].CC[O-].CC[O-].CC[O-] Chemical compound [Ce+4].CC[O-].CC[O-].CC[O-].CC[O-] GWBCIGVMZFHCLA-UHFFFAOYSA-N 0.000 description 1
- XKGMHABTFTUWDV-UHFFFAOYSA-N [W+4].CC(C)[O-].CC(C)[O-].CC(C)[O-].CC(C)[O-] Chemical compound [W+4].CC(C)[O-].CC(C)[O-].CC(C)[O-].CC(C)[O-] XKGMHABTFTUWDV-UHFFFAOYSA-N 0.000 description 1
- XQYHGRBUQMYZMW-UHFFFAOYSA-N [W+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] Chemical compound [W+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] XQYHGRBUQMYZMW-UHFFFAOYSA-N 0.000 description 1
- OIIGPGKGVNSPBV-UHFFFAOYSA-N [W+4].CC[O-].CC[O-].CC[O-].CC[O-] Chemical compound [W+4].CC[O-].CC[O-].CC[O-].CC[O-] OIIGPGKGVNSPBV-UHFFFAOYSA-N 0.000 description 1
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- 125000003158 alcohol group Chemical group 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000001339 alkali metal compounds Chemical class 0.000 description 1
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- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229960005070 ascorbic acid Drugs 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- IXSUHTFXKKBBJP-UHFFFAOYSA-L azanide;platinum(2+);dinitrite Chemical compound [NH2-].[NH2-].[Pt+2].[O-]N=O.[O-]N=O IXSUHTFXKKBBJP-UHFFFAOYSA-L 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- HDMXIELEUKTYFR-UHFFFAOYSA-N bis(2-ethylhexyl) butanedioate;sodium Chemical compound [Na].CCCCC(CC)COC(=O)CCC(=O)OCC(CC)CCCC HDMXIELEUKTYFR-UHFFFAOYSA-N 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- ZRUGDHIOIFRJIQ-UHFFFAOYSA-N butan-1-olate cerium(4+) Chemical compound CCCCO[Ce](OCCCC)(OCCCC)OCCCC ZRUGDHIOIFRJIQ-UHFFFAOYSA-N 0.000 description 1
- YHWCPXVTRSHPNY-UHFFFAOYSA-N butan-1-olate;titanium(4+) Chemical compound [Ti+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] YHWCPXVTRSHPNY-UHFFFAOYSA-N 0.000 description 1
- BSDOQSMQCZQLDV-UHFFFAOYSA-N butan-1-olate;zirconium(4+) Chemical compound [Zr+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] BSDOQSMQCZQLDV-UHFFFAOYSA-N 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- CWQUQZODOUNODL-UHFFFAOYSA-L calcium;hexadecyl sulfate Chemical compound [Ca+2].CCCCCCCCCCCCCCCCOS([O-])(=O)=O.CCCCCCCCCCCCCCCCOS([O-])(=O)=O CWQUQZODOUNODL-UHFFFAOYSA-L 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 150000007942 carboxylates Chemical class 0.000 description 1
- BCBBBOXRROHVFG-UHFFFAOYSA-N cerium(4+);propan-2-olate Chemical compound [Ce+4].CC(C)[O-].CC(C)[O-].CC(C)[O-].CC(C)[O-] BCBBBOXRROHVFG-UHFFFAOYSA-N 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- WOWHHFRSBJGXCM-UHFFFAOYSA-M cetyltrimethylammonium chloride Chemical compound [Cl-].CCCCCCCCCCCCCCCC[N+](C)(C)C WOWHHFRSBJGXCM-UHFFFAOYSA-M 0.000 description 1
- 235000015165 citric acid Nutrition 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 239000011246 composite particle Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
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- WLCFKPHMRNPAFZ-UHFFFAOYSA-M didodecyl(dimethyl)azanium;chloride Chemical compound [Cl-].CCCCCCCCCCCC[N+](C)(C)CCCCCCCCCCCC WLCFKPHMRNPAFZ-UHFFFAOYSA-M 0.000 description 1
- OGQYPPBGSLZBEG-UHFFFAOYSA-N dimethyl(dioctadecyl)azanium Chemical compound CCCCCCCCCCCCCCCCCC[N+](C)(C)CCCCCCCCCCCCCCCCCC OGQYPPBGSLZBEG-UHFFFAOYSA-N 0.000 description 1
- IRMGVPILCPGYNQ-UHFFFAOYSA-M dimethyl-di(tetradecyl)azanium;bromide Chemical compound [Br-].CCCCCCCCCCCCCC[N+](C)(C)CCCCCCCCCCCCCC IRMGVPILCPGYNQ-UHFFFAOYSA-M 0.000 description 1
- RSHHCURRBLAGFA-UHFFFAOYSA-M dimethyl-di(tetradecyl)azanium;chloride Chemical compound [Cl-].CCCCCCCCCCCCCC[N+](C)(C)CCCCCCCCCCCCCC RSHHCURRBLAGFA-UHFFFAOYSA-M 0.000 description 1
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- DDXLVDQZPFLQMZ-UHFFFAOYSA-M dodecyl(trimethyl)azanium;chloride Chemical compound [Cl-].CCCCCCCCCCCC[N+](C)(C)C DDXLVDQZPFLQMZ-UHFFFAOYSA-M 0.000 description 1
- JRBPAEWTRLWTQC-UHFFFAOYSA-N dodecylamine Chemical compound CCCCCCCCCCCCN JRBPAEWTRLWTQC-UHFFFAOYSA-N 0.000 description 1
- QVAZSFSQBKLKMP-UHFFFAOYSA-N dodecylazanium;propanoate Chemical compound CCC([O-])=O.CCCCCCCCCCCC[NH3+] QVAZSFSQBKLKMP-UHFFFAOYSA-N 0.000 description 1
- XJWSAJYUBXQQDR-UHFFFAOYSA-M dodecyltrimethylammonium bromide Chemical compound [Br-].CCCCCCCCCCCC[N+](C)(C)C XJWSAJYUBXQQDR-UHFFFAOYSA-M 0.000 description 1
- ASBGGHMVAMBCOR-UHFFFAOYSA-N ethanolate;zirconium(4+) Chemical compound [Zr+4].CC[O-].CC[O-].CC[O-].CC[O-] ASBGGHMVAMBCOR-UHFFFAOYSA-N 0.000 description 1
- 229940117927 ethylene oxide Drugs 0.000 description 1
- 239000006023 eutectic alloy Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
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- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 230000000640 hydroxylating effect Effects 0.000 description 1
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- 229910000765 intermetallic Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- BJZBHTNKDCBDNQ-UHFFFAOYSA-L magnesium;dodecanoate Chemical compound [Mg+2].CCCCCCCCCCCC([O-])=O.CCCCCCCCCCCC([O-])=O BJZBHTNKDCBDNQ-UHFFFAOYSA-L 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910001092 metal group alloy Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 1
- 238000009740 moulding (composite fabrication) Methods 0.000 description 1
- UJVRJBAUJYZFIX-UHFFFAOYSA-N nitric acid;oxozirconium Chemical class [Zr]=O.O[N+]([O-])=O.O[N+]([O-])=O UJVRJBAUJYZFIX-UHFFFAOYSA-N 0.000 description 1
- 150000002826 nitrites Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229940049964 oleate Drugs 0.000 description 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- MUMZUERVLWJKNR-UHFFFAOYSA-N oxoplatinum Chemical compound [Pt]=O MUMZUERVLWJKNR-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- VNVJGCRCHNRLGG-UHFFFAOYSA-N phenyl octadecanoate;sodium Chemical compound [Na].CCCCCCCCCCCCCCCCCC(=O)OC1=CC=CC=C1 VNVJGCRCHNRLGG-UHFFFAOYSA-N 0.000 description 1
- 229910003446 platinum oxide Inorganic materials 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- IKNCGYCHMGNBCP-UHFFFAOYSA-N propan-1-olate Chemical compound CCC[O-] IKNCGYCHMGNBCP-UHFFFAOYSA-N 0.000 description 1
- ZGSOBQAJAUGRBK-UHFFFAOYSA-N propan-2-olate;zirconium(4+) Chemical compound [Zr+4].CC(C)[O-].CC(C)[O-].CC(C)[O-].CC(C)[O-] ZGSOBQAJAUGRBK-UHFFFAOYSA-N 0.000 description 1
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- 238000005245 sintering Methods 0.000 description 1
- 239000001509 sodium citrate Substances 0.000 description 1
- NLJMYIDDQXHKNR-UHFFFAOYSA-K sodium citrate Chemical compound O.O.[Na+].[Na+].[Na+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O NLJMYIDDQXHKNR-UHFFFAOYSA-K 0.000 description 1
- 235000011083 sodium citrates Nutrition 0.000 description 1
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 1
- 235000019345 sodium thiosulphate Nutrition 0.000 description 1
- DHQIJSYTNIUZRY-UHFFFAOYSA-M sodium;2,3-di(nonyl)naphthalene-1-sulfonate Chemical compound [Na+].C1=CC=C2C(S([O-])(=O)=O)=C(CCCCCCCCC)C(CCCCCCCCC)=CC2=C1 DHQIJSYTNIUZRY-UHFFFAOYSA-M 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- DWCVOTSGWLRENH-UHFFFAOYSA-M tetrakis(3-methylbutyl)azanium;thiocyanate Chemical compound [S-]C#N.CC(C)CC[N+](CCC(C)C)(CCC(C)C)CCC(C)C DWCVOTSGWLRENH-UHFFFAOYSA-M 0.000 description 1
- ZUEKXCXHTXJYAR-UHFFFAOYSA-N tetrapropan-2-yl silicate Chemical compound CC(C)O[Si](OC(C)C)(OC(C)C)OC(C)C ZUEKXCXHTXJYAR-UHFFFAOYSA-N 0.000 description 1
- JMXKSZRRTHPKDL-UHFFFAOYSA-N titanium ethoxide Chemical compound [Ti+4].CC[O-].CC[O-].CC[O-].CC[O-] JMXKSZRRTHPKDL-UHFFFAOYSA-N 0.000 description 1
- WBKJPJYWZAGQKL-UHFFFAOYSA-M tributyl(octadecyl)azanium;formate Chemical compound [O-]C=O.CCCCCCCCCCCCCCCCCC[N+](CCCC)(CCCC)CCCC WBKJPJYWZAGQKL-UHFFFAOYSA-M 0.000 description 1
- DQYBHCRUGXGVNS-UHFFFAOYSA-M tributyl(pentyl)azanium;iodide Chemical compound [I-].CCCCC[N+](CCCC)(CCCC)CCCC DQYBHCRUGXGVNS-UHFFFAOYSA-M 0.000 description 1
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 229940105125 zinc myristate Drugs 0.000 description 1
- NVKSAUAQUPYOPO-UHFFFAOYSA-L zinc;decanoate Chemical compound [Zn+2].CCCCCCCCCC([O-])=O.CCCCCCCCCC([O-])=O NVKSAUAQUPYOPO-UHFFFAOYSA-L 0.000 description 1
- GBFLQPIIIRJQLU-UHFFFAOYSA-L zinc;tetradecanoate Chemical compound [Zn+2].CCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCC([O-])=O GBFLQPIIIRJQLU-UHFFFAOYSA-L 0.000 description 1
Abstract
Description
本発明は、ナノ細孔を有するハニカムに触媒成分が塗布されたナノハニカム触媒および、ナノ細孔を有するハニカムに逆ミセル溶液を用いて触媒成分を担持する、ナノハニカム触媒の製造方法に関する。 The present invention relates to a nanohoneycomb catalyst in which a catalyst component is applied to a honeycomb having nanopores, and a method for producing a nanohoneycomb catalyst in which a catalyst component is supported on a honeycomb having nanopores using a reverse micelle solution.
貴金属を触媒成分とし、これを担体成分に担持した触媒は、酸化あるいは還元反応、あるいは、化学合成用の触媒として広範に利用されている。最近では、活性成分である貴金属の粒子径と反応ガス成分との接触頻度を増大するため、貴金属粒子サイズを数ｎｍ、例えば１０ｎｍ以下に小さくし、粒子表面積を大きくすることが求められている。また、触媒成分層と反応ガス成分との反応効率を増大するために、該触媒に助触媒成分として他の成分を混合・粉砕し、得られたスラリーをコージェライト質ハニカム担体に塗布し、乾燥・焼成したものもある。 A catalyst in which a noble metal is used as a catalyst component and this is supported on a carrier component is widely used as a catalyst for oxidation or reduction reaction or chemical synthesis. Recently, in order to increase the contact frequency between the particle size of the noble metal as the active component and the reaction gas component, it is required to reduce the noble metal particle size to several nm, for example, 10 nm or less, and increase the particle surface area. Further, in order to increase the reaction efficiency between the catalyst component layer and the reaction gas component, the catalyst is mixed and pulverized with other components as a promoter component, and the resulting slurry is applied to a cordierite honeycomb carrier and dried.・ Some fired products.
しかしながら、従来の含浸法や浸漬法、沈殿法などで使用する触媒成分や助触媒成分としては、無機酸化物粉末や貴金属粉末などが使用され、これらの粒子サイズは数μｍ〜数１００μｍである。このため、ボールミルなどの手段で粉砕・スラリー化した後も、一般に１μｍ〜数μｍの粒子サイズとなり、数μｍ〜数１０μｍの細孔構造を有すコージェライト質ハニカム担体に塗布すると、触媒層は必然的に数μｍ〜数１０μｍの厚みとなる。 However, as the catalyst component and the promoter component used in the conventional impregnation method, dipping method, precipitation method, etc., inorganic oxide powder, noble metal powder, etc. are used, and the particle size thereof is several μm to several hundred μm. Therefore, even after pulverization / slurry by means such as a ball mill, the catalyst layer generally has a particle size of 1 μm to several μm and is applied to a cordierite honeycomb carrier having a pore structure of several μm to several tens of μm. Inevitably, the thickness is several μm to several tens of μm.
また、触媒活性成分と反応ガス成分との反応効率を増大して活性向上を図るには、貴金属粒子サイズを数ｎｍ程度に小さくし粒子表面積を大きくし、さらに、触媒成分塗布層の厚みを数１０ｎｍ〜数１００ｎｍ程度に薄くして、触媒層内のガス拡散抵抗を小さくすることも有効である。 In order to improve the activity by increasing the reaction efficiency between the catalytically active component and the reactive gas component, the noble metal particle size is reduced to about several nanometers, the particle surface area is increased, and the thickness of the catalyst component coating layer is reduced to a few. It is also effective to reduce the gas diffusion resistance in the catalyst layer by reducing the thickness to about 10 nm to several 100 nm.
しかしながら、従来のハニカム触媒では、触媒活性種と反応ガス成分との反応効率が不十分である。すなわち本発明の目的は、従来の製造方法でマイクロ細孔構造のハニカム担体に触媒成分層を塗布することに代り、逆ミセル溶液を使用してナノ細孔構造のハニカム担体に触媒成分層を形成し、触媒成分層と反応ガス成分との反応効率を増大して活性向上を図ることにある。 However, in the conventional honeycomb catalyst, the reaction efficiency between the catalytically active species and the reactive gas component is insufficient. That is, an object of the present invention is to form a catalyst component layer on a nanoporous structure honeycomb carrier using a reverse micelle solution instead of applying a catalyst component layer to a microporous honeycomb support by a conventional manufacturing method. Then, the reaction efficiency between the catalyst component layer and the reaction gas component is increased to improve the activity.
上記目的を達成するため、ハニカム担体として規則的なナノ細孔を有するハニカムに、数ｎｍの貴金属粒子と担体成分とを担持させた構造にすることで、触媒活性の向上を図ることができる。貴金属粒子と共に助触媒として卑金属を担持すると、更に耐熱性に優れるナノハニカム触媒とすることができる。 In order to achieve the above object, catalytic activity can be improved by adopting a structure in which noble metal particles of several nm and a carrier component are supported on a honeycomb having regular nanopores as a honeycomb carrier. When a base metal is supported as a co-catalyst together with noble metal particles, a nano honeycomb catalyst having further excellent heat resistance can be obtained.
このようなナノハニカム触媒は、ミセル内部に貴金属イオン水溶液を含有する逆ミセル溶液に、該貴金属イオンの不溶化剤を添加し、得られた溶液をハニカムに充填し、次いで金属担体成分アルコキシド溶液あるいは金属担体成分アルコキシドの加水分解物を含む逆ミセル溶液（Ｃ）を該ナノハニカムに添加する工程を有することで調製することができる。 In such a nanohoneycomb catalyst, an insolubilizing agent for the noble metal ions is added to a reverse micelle solution containing a noble metal ion aqueous solution inside the micelle, the resulting solution is filled in the honeycomb, and then the metal carrier component alkoxide solution or metal It can be prepared by adding a reverse micelle solution (C) containing a hydrolyzate of the carrier component alkoxide to the nanohoneycomb.
本発明のナノハニカム触媒によれば、触媒成分である貴金属微粒子がナノハニカムに薄層に担持されており、触媒活性を高めることができる。該触媒は、触媒成分に加えて助触媒として卑金属も担持すると、活性成分と反応ガス成分との反応効率の向上、さらに、触媒層内のガス拡散速度による反応効率の向上を図ることができる。 According to the nanohoneycomb catalyst of the present invention, the noble metal fine particles as the catalyst component are supported on the nanohoneycomb in a thin layer, and the catalytic activity can be enhanced. When the catalyst carries a base metal as a co-catalyst in addition to the catalyst component, it is possible to improve the reaction efficiency between the active component and the reaction gas component and further improve the reaction efficiency due to the gas diffusion rate in the catalyst layer.
本発明のナノハニカム触媒の製造方法によれば、逆ミセル法を用いて調製した貴金属コロイドと卑金属水酸化物とを含有したミセルを、規則的なナノ細孔構造を有すハニカム担体の細孔内壁上に付着した後にアルミニウム担体成分アルコキシド等の担体成分を添加することで、ナノハニカム上に貴金属、卑金属が担持されたアルミナを薄層でナノハニカムに担持することができる。これを、乾燥・焼成すると、規則的なナノ細孔構造を有すハニカム担体内に、ナノサイズの触媒成分を形成した触媒が調製できる。 According to the method for producing a nanohoneycomb catalyst of the present invention, a micelle containing a noble metal colloid and a base metal hydroxide prepared using a reverse micelle method is used as a pore of a honeycomb carrier having a regular nanopore structure. By adding a carrier component such as an aluminum carrier component alkoxide after adhering to the inner wall, alumina having a noble metal or a base metal supported on the nanohoneycomb can be supported on the nanohoneycomb in a thin layer. When this is dried and fired, a catalyst in which a nanosized catalyst component is formed in a honeycomb carrier having a regular nanopore structure can be prepared.
該発明によれば、従来困難であったナノハニカムへの貴金属微粒子の担持が容易であり、しかも逆ミセル溶液を使用するため、触媒粒子の組成を均一化できる。該方法では、貴金属微粒子に加えて助触媒成分として例えば卑金属を担持させることも容易である。不活性ガス雰囲気下で焼成工程を経た後も、貴金属合金粒子が凝集やシンタリングすることなく高分散に担持することができ、さらに性能を向上できる。 According to the invention, it is easy to support the noble metal fine particles on the nanohoneycomb, which has been difficult in the past, and the composition of the catalyst particles can be made uniform because the reverse micelle solution is used. In this method, it is easy to carry, for example, a base metal as a promoter component in addition to the noble metal fine particles. Even after the firing step in an inert gas atmosphere, the noble metal alloy particles can be supported in a highly dispersed state without agglomeration or sintering, and the performance can be further improved.
本発明の第一は、ナノハニカム内壁に、貴金属粒子と担体成分とが被覆されたナノハニカム触媒である。ナノハニカム内壁に、更に卑金属酸化物が被覆されていてもよい。該ナノハニカムは、メタル箔表面に形成されたナノハニカムであることが好ましい。 The first aspect of the present invention is a nanohoneycomb catalyst in which a nanohoneycomb inner wall is coated with noble metal particles and a carrier component. The nano honeycomb inner wall may be further coated with a base metal oxide. The nanohoneycomb is preferably a nanohoneycomb formed on the surface of the metal foil.
従来からハニカム触媒は存在したが、ナノ細孔のハニカムに触媒成分を担持したものは存在しなかった。これは、ナノハニカムに担持できるほど触媒成分を微粒子に調製することができないことが原因であった。すなわち、一般には貴金属などの触媒成分をアルミナ等の担体成分と混合して触媒スラリーを調整し、該スラリーをハニカムに含浸または塗布して触媒成分をハニカムに担持させていたが、ボールミルなどの手段で粉砕・スラリー化した後も、１〜数μｍの粒子サイズとなるため、ハニカム内に目詰まりするためである。 Conventionally, there has been a honeycomb catalyst, but there has not been a catalyst having a catalyst component supported on a nanoporous honeycomb. This was because the catalyst component could not be prepared into fine particles so that it could be supported on the nanohoneycomb. That is, in general, a catalyst component such as a noble metal is mixed with a carrier component such as alumina to prepare a catalyst slurry, and the catalyst component is supported on the honeycomb by impregnating or applying the slurry to the honeycomb. This is because the particle size is 1 to several μm even after pulverizing and slurrying in order to clog the honeycomb.
しかしながら本発明のナノハニカム触媒は、貴金属コロイドを含む逆ミセル溶液をナノハニカムの細孔に被覆し、次いで、不溶化処理を施した後、更に該担体成分アルコキシドを該ナノハニカムに添加し加水分解反応を経て貴金属粒子を担体成分に担持させ、該ナノハニカムを洗浄、乾燥および焼成してなるナノハニカム触媒である。貴金属と担体成分とを含むスラリーを使用することなく、まず貴金属コロイドを含む逆ミセル溶液を使用することで極めて微粒子の貴金属をナノハニカムに均一に担持させることができる。逆ミセル溶液の調製方法や適宜については第二の発明で詳記するが、界面活性剤の種類や添加量を調整することでミセルサイズを変化させることができ、該ミセルサイズに準じてミセル内の金属イオンが凝集する。このため、ミセルサイズを微細にして貴金属粒子径をより微細にすることができるのである。しかも、貴金属の担持はミセルサイズに制限されるため均一な担持が可能となる。 However, in the nanohoneycomb catalyst of the present invention, the reverse micelle solution containing the noble metal colloid is coated on the pores of the nanohoneycomb, then insolubilized, and then the carrier component alkoxide is further added to the nanohoneycomb for hydrolysis reaction. The nanohoneycomb catalyst is obtained by supporting noble metal particles on a carrier component through cleaning, washing, drying and firing the nanohoneycomb. By using a reverse micelle solution containing a noble metal colloid without using a slurry containing a noble metal and a support component, extremely fine noble metal can be uniformly supported on the nanohoneycomb. Although the preparation method of the reverse micelle solution and the appropriate method will be described in detail in the second invention, the micelle size can be changed by adjusting the type and addition amount of the surfactant, and the micelle size can be changed according to the micelle size. Metal ions agglomerate. For this reason, the micelle size can be made fine and the noble metal particle diameter can be made finer. In addition, since the loading of the noble metal is limited to the micelle size, uniform loading is possible.
該触媒成分を担持する担体成分としては、アルミニウム、シリコン、チタニウム、セリウム、ジルコニウム、バナジウム、およびタングステンがあるが、特に、アルミニウムアルコキシドなどの担体成分アルコキシドが望ましい。担体成分アルコキシドの種類や添加方法なども第二の発明で詳記するが、ここでは該担体成分アルコキシドを使用する原理を簡単に説明する。まず、貴金属コロイドや卑金属の水溶性化合物を含む逆ミセル溶液をナノハニカム細孔内に均一に付着させる。次いで、該担体成分アルコキシドを添加すると、ナノハニカム表面に均一に付着した逆ミセル内の水（可溶化水）でアルコキシドが加水分解され担体水酸化物を生成する。このナノハニカムを洗浄、乾燥および焼成すると、貴金属粒子と卑金属酸化物（助触媒成分の酸化物）が担体成分酸化物に担持される。 Examples of the carrier component that supports the catalyst component include aluminum, silicon, titanium, cerium, zirconium, vanadium, and tungsten. In particular, a carrier component alkoxide such as aluminum alkoxide is desirable. The kind of the carrier component alkoxide and the addition method are also described in detail in the second invention. Here, the principle of using the carrier component alkoxide will be briefly described. First, a reverse micelle solution containing a noble metal colloid or a water-soluble compound of a base metal is uniformly deposited in the nanohoneycomb pores. Next, when the carrier component alkoxide is added, the alkoxide is hydrolyzed with water (solubilized water) in the reverse micelles uniformly attached to the nanohoneycomb surface to produce a carrier hydroxide. When the nanohoneycomb is washed, dried and fired, the noble metal particles and the base metal oxide (the oxide of the promoter component) are supported on the carrier component oxide.
具体的にアルミニウムイソプロポキシドなどのアルミニウム担体成分アルコキシドを例にすると、貴金属コロイドや卑金の水溶性化合物を含む逆ミセル溶液をナノハニカム細孔内に均一に付着させる。次いで、該担体成分アルミニウムイソプロポキシドを添加すると、ナノハニカム表面に均一に付着した逆ミセル内の水（可溶化水）でアルミニウムイソプロポキシドが加水分解され担体水酸化アルミニウムを生成する。ナノハニカム上（細孔内の表面）は、貴金属粒子と卑金属水酸化物を含有する水酸化アルミニウムによって均一に被覆される。これを焼成すると、卑金属水酸化物が酸化物に、水酸化アルミニウムがアルミナとなり、貴金属粒子と卑金属酸化物（助触媒成分の酸化物）がアルミナに担持された触媒成分層が形成される。よって、規則的なナノ細孔構造を有するハニカム担体内に、厚さがナノサイズに制御された貴金属、卑金属およびアルミナを担持したナノハニカム触媒となる。このような方法で調製されたナノハニカム触媒は、貴金属、卑金属、担体成分が均一かつ薄層に高分散され、従来全く存在しないものである。 Specifically, taking an aluminum carrier component alkoxide such as aluminum isopropoxide as an example, a reverse micelle solution containing a noble metal colloid or a base metal water-soluble compound is uniformly deposited in the nanohoneycomb pores. Next, when the carrier component aluminum isopropoxide is added, the aluminum isopropoxide is hydrolyzed with water (solubilized water) in the reverse micelles uniformly attached to the nanohoneycomb surface to produce carrier aluminum hydroxide. The nano honeycomb (surface in the pores) is uniformly coated with aluminum hydroxide containing noble metal particles and base metal hydroxide. When this is fired, a catalyst component layer is formed in which base metal hydroxide becomes oxide, aluminum hydroxide becomes alumina, and noble metal particles and base metal oxide (oxide of promoter component) are supported on alumina. Therefore, a nanohoneycomb catalyst in which a noble metal, a base metal, and alumina whose thickness is controlled to a nano size is supported in a honeycomb carrier having a regular nanopore structure. The nano-honeycomb catalyst prepared by such a method has noble metals, base metals, and carrier components uniformly and highly dispersed in a thin layer and does not exist at all.
本発明のナノハニカム触媒を構成するナノハニカムは、ナノ細孔を有するハニカムであり、材質は問わない。しかしながら、ハニカム構造の形成のしやすさからアルミニウム、などのメタルであることが好ましい。特に、メタル箔表面に形成されたナノハニカムであることが好ましい。このようなナノハニカムとしては、例えば酸にアルミニウムの入った液体を入れて電圧をかけて表面に酸化膜を形成すると微細な穴を持った酸化被膜が成長することを利用して調製されたものが使用できる。例えば図１に示すように、予めメタル箔上に規則性の有る格子状に小さな点あるいは格子状の網目を打ったものを用い、これを酸にアルミニウムが溶解した溶液に浸漬し、電解反応にてメタル箔上にアルミニウムの酸化膜を形成すると、格子点あるいは網目に沿って酸化膜が成長し、これが壁となったナノ細孔を有するハニカムとなる。縦横に等間隔に点を打つと四角格子に、三角形の頂点に点を打てば三角格子に、六角形の頂点に点を打てば六角格子が規則的に並んだハニカム構造になる。なお、本発明のナノハニカムとは、細孔を形成するハニカム格子の断面積が、幾何学的表面積が、１０〜５０ｃｍ２／ｃｍ３のものをいう。 The nanohoneycomb constituting the nanohoneycomb catalyst of the present invention is a honeycomb having nanopores, and the material is not limited. However, it is preferable to use a metal such as aluminum because it is easy to form a honeycomb structure. In particular, a nano honeycomb formed on the surface of the metal foil is preferable. Such a nano-honeycomb was prepared by utilizing the fact that an oxide film with fine holes grows when an oxide film is formed on the surface by applying a voltage by applying a liquid containing aluminum into acid. Can be used. For example, as shown in FIG. 1, a metal foil having a regular grid-like small dot or grid-like mesh is preliminarily used and immersed in a solution of aluminum dissolved in an acid for the electrolytic reaction. Then, when an aluminum oxide film is formed on the metal foil, the oxide film grows along lattice points or meshes, and this becomes a honeycomb having nanopores as walls. When dots are placed at equal intervals in the vertical and horizontal directions, a honeycomb structure is formed in which a square lattice is regularly arranged in a square lattice, if dots are applied to the vertices of triangles, triangle lattices are formed. The nanohoneycomb of the present invention refers to a honeycomb lattice having pores with a cross-sectional area of 10 to 50 cm 2 / cm 3 and a geometric surface area.
本発明のナノハニカム触媒は、貴金属コロイドを含む逆ミセル溶液をナノハニカムの細孔に分散し、これに更に担体成分を添加して、ナノハニカム細孔内の逆ミセル内で貴金属担持水酸化物を形成し、該ナノハニカムを洗浄、乾燥および焼成する工程によって、該ナノハニカム細孔内に貴金属担持触媒（酸化物）層が調製されるものである。貴金属コロイドを含む逆ミセル溶液には、平均粒子径が１〜１０ｎｍの貴金属粒子をコロイド状に含むため、このような超微粒子の貴金属をナノハニカムに担持させることができる。この際、該逆ミセル溶液に卑金属イオンが含まれると、貴金属と卑金属酸化物とを担持した担体成分をナノハニカムに担持させることができる。なお、焼成処理により、貴金属と卑金属の合金を担持した担体成分をナノハニカムに担持することもできる。合金とは、一般に金属元素に１種以上の金属元素または非金属元素を加えたものであって、金属的性質をもっているものの総称である。合金の組織には、成分元素が別個の結晶となるいわば混合物である共晶合金、成分元素が完全にとけ合い固溶体となっているもの、成分元素が金属間化合物または金属と非金属との化合物を形成しているものなどがあり、本願ではいずれであってもよい。 The nano honeycomb catalyst of the present invention is obtained by dispersing a reverse micelle solution containing a noble metal colloid in the pores of the nano honeycomb, and further adding a carrier component to the noble metal supported hydroxide in the reverse micelles in the nano honeycomb pores. The noble metal-supported catalyst (oxide) layer is prepared in the pores of the nanohoneycomb by the steps of forming, cleaning, drying and firing the nanohoneycomb. Since the reverse micelle solution containing the noble metal colloid contains colloidal noble metal particles having an average particle diameter of 1 to 10 nm, such ultrafine noble metal can be supported on the nanohoneycomb. At this time, if base metal ions are contained in the reverse micelle solution, the carrier component supporting the noble metal and the base metal oxide can be supported on the nanohoneycomb. Note that a carrier component carrying a noble metal-base metal alloy can also be carried on the nanohoneycomb by firing treatment. An alloy is a general term for a metal element having one or more metal elements or non-metal elements added and having metallic properties. The alloy structure includes a eutectic alloy, which is a mixture of the constituent elements as separate crystals, a solid solution in which the constituent elements are completely mixed, and the constituent element is an intermetallic compound or a compound of a metal and a nonmetal. In the present application, any of them may be used.
本発明のナノハニカム触媒を構成する貴金属は、白金、パラジウム、ロジウム、オスミウム、ルテニウム及びイリジウムからなる群より選ばれる少なくとも一種である。ナノハニカム触媒には、貴金属粒子として担持されても、焼成によって貴金属酸化物粒子として担持されていてもよい。また、二種の貴金属の合金粒子として担持されていてもよい。 The noble metal constituting the nano honeycomb catalyst of the present invention is at least one selected from the group consisting of platinum, palladium, rhodium, osmium, ruthenium and iridium. The nano honeycomb catalyst may be supported as noble metal particles or may be supported as noble metal oxide particles by firing. Moreover, you may carry | support as an alloy particle of two types of noble metals.
また、卑金属としては、セリウム、プラセオジウム、ジルコニウム、マンガン、鉄、コバルト、ニッケル及びバリウムからなる群より選ばれた少なくとも一種であることが好ましい。ナノハニカム触媒には、卑金属粒子として担持されても、焼成によって卑金属酸化物粒子として担持されていてもよい。また、貴金属との合金粒子として担持されていてもよい。 The base metal is preferably at least one selected from the group consisting of cerium, praseodymium, zirconium, manganese, iron, cobalt, nickel and barium. The nano honeycomb catalyst may be supported as base metal particles or may be supported as base metal oxide particles by firing. Moreover, you may carry | support as an alloy particle with a noble metal.
更に、該ナノハニカム触媒には、貴金属や卑金属の担体成分も担持される。このような担体成分としては、アルミニウム、シリコン、チタニウム、セリウム、ジルコニウム、タングステンなどがある。 Furthermore, the nano honeycomb catalyst also supports a noble metal or base metal carrier component. Such carrier components include aluminum, silicon, titanium, cerium, zirconium, tungsten, and the like.
本発明のナノハニカム触媒に担持する貴金属粒子、卑金属粒子、または貴金属と卑金属とからなる合金粒子の平均粒子径は、１〜１０ｎｍ、より好ましくは２〜５ｎｍである。平均粒子径がこの範囲であれば、触媒活性に十分な表面積が確保でき、貴金属の単位質量当たりの触媒活性量を増大させることができる。なお、本発明において触媒金属の平均粒子径とは、Ｘ線回析における触媒金属の回析ピークの半値幅より求められる結晶子径や透過型電子顕微鏡より調べられる触媒金属の粒子径の平均値で算出することができる。 The average particle diameter of the noble metal particles, the base metal particles, or the alloy particles composed of the noble metal and the base metal supported on the nano honeycomb catalyst of the present invention is 1 to 10 nm, more preferably 2 to 5 nm. If the average particle diameter is within this range, a surface area sufficient for catalytic activity can be secured, and the amount of catalytic activity per unit mass of the noble metal can be increased. In the present invention, the average particle diameter of the catalyst metal is the average value of the crystallite diameter determined from the half-value width of the diffraction peak of the catalyst metal in X-ray diffraction or the particle diameter of the catalyst metal determined from a transmission electron microscope. Can be calculated.
なお、本発明のナノハニカム触媒において、担持する金属量は、貴金属と卑金属との合計量として、金属量がナノハニカムあたり０．１〜２０ｇ／ｌｉｔｅｒ、より好ましくは１〜１０ｇ／ｌｉｔｅｒである。金属の坦持量が、０．１ｇ／ｌｉｔｅｒ未満では充分な活性や耐久性が得られない。また、２０ｇ／ｌｉｔｅｒを超えると均一に分散し難く、触媒金属粒子の高分散坦持が困難となる。本発明のナノハニカム触媒は、本発明の第二によって製造することができる。 In the nano honeycomb catalyst of the present invention, the amount of metal supported is 0.1 to 20 g / liter, more preferably 1 to 10 g / liter per nano honeycomb as the total amount of noble metal and base metal. If the supported amount of metal is less than 0.1 g / liter, sufficient activity and durability cannot be obtained. Moreover, when it exceeds 20 g / liter, it is difficult to disperse | distribute uniformly and it becomes difficult to carry | support highly dispersed catalyst metal particle. The nano honeycomb catalyst of the present invention can be produced by the second of the present invention.
本発明の第二は、ミセル内部に貴金属イオン水溶液を含有する逆ミセル溶液に、該貴金属イオンの不溶化剤を添加し、得られた溶液をハニカムに充填し、次いで担体成分アルコキシド溶液あるいは担体成分アルコキシドの加水分解物を含む逆ミセル溶液（Ｃ）を該ナノハニカムに添加する工程を有することを特徴とする、ナノハニカム触媒の製造方法である。逆ミセル法を使用することで析出する貴金属粒子の大きさを調整することができ、より微細な貴金属粒子を担持させることができる。また、逆ミセル溶液を使用することで、担体表面に略等間隔で金属粒子を担持させることができる。 In the second aspect of the present invention, a reverse micelle solution containing a noble metal ion aqueous solution inside the micelle is added with an insolubilizing agent for the noble metal ions, and the resulting solution is filled in a honeycomb, and then the carrier component alkoxide solution or the carrier component alkoxide is filled. A method for producing a nanohoneycomb catalyst, comprising the step of adding a reverse micelle solution (C) containing a hydrolyzate of the above to the nanohoneycomb. By using the reverse micelle method, the size of the precious metal particles deposited can be adjusted, and finer precious metal particles can be supported. Further, by using the reverse micelle solution, the metal particles can be supported on the carrier surface at substantially equal intervals.
本発明で使用する「逆ミセル溶液」とは、有機溶媒に界面活性剤分子等の両親媒性物質を混合して形成される該両親媒性物質が集合して形成されるミセルを含有し、かつ該ミセル内に貴金属イオン水溶液および／または卑金属イオン水溶液を含有する溶液である。有機溶媒相内で疎水性基を外側すなわち有機溶媒相側に向け、親水性基を内側に向けて配向し、疎水性基と親水性基の配向が水性溶媒相の場合と逆であるため、逆ミセル溶液とする。逆ミセル溶液を模式的に示す図が図２である。このような逆ミセル溶液は、界面活性剤を有機溶媒に溶解した溶液に水溶液を加えて撹拌して調製することができる。親水性基が集まった部分には水などの極性分子を保持する能力がある。該水溶液は、直径１０〜１００ｎｍ程度の極めて小さな水滴となって有機溶媒中に安定に分散するが、注入した水と界面活性剤のモル比によって逆ミセルの微細組織の大きさを制御することができる。 The “reverse micelle solution” used in the present invention contains micelles formed by assembling the amphiphiles formed by mixing an amphiphile such as a surfactant molecule in an organic solvent, The micelle contains a noble metal ion aqueous solution and / or a base metal ion aqueous solution. In the organic solvent phase, the hydrophobic group is oriented to the outside, that is, the organic solvent phase side, the hydrophilic group is oriented to the inside, and the orientation of the hydrophobic group and the hydrophilic group is opposite to that in the aqueous solvent phase. Use reverse micelle solution. FIG. 2 schematically shows the reverse micelle solution. Such a reverse micelle solution can be prepared by adding an aqueous solution to a solution obtained by dissolving a surfactant in an organic solvent and stirring the solution. The portion where the hydrophilic groups are gathered has the ability to retain polar molecules such as water. The aqueous solution becomes very small water droplets having a diameter of about 10 to 100 nm and is stably dispersed in the organic solvent. However, the size of the microstructure of the reverse micelle can be controlled by the molar ratio of the injected water and the surfactant. it can.
例えば、ミセル内部に貴金属イオン水溶液を含有する逆ミセル溶液に、該貴金属イオンの不溶化剤を添加すると、ミセル内部で貴金属イオンが貴金属に不溶化剤され、コロイド状の貴金属粒子となる。貴金属イオンの不溶化剤は、水溶液として添加しても、該不溶化剤をミセル内部に含有する逆ミセル溶液として添加してもよい。図３に、不溶化剤を逆ミセル溶液で添加する場合を模式図に示す。まず、図３（Ａ）に示すように、有機溶媒１に界面活性剤２を混合し、これに貴金属イオン水溶液を加えると、親水性基３を内側に疎水性基４を外側にするミセル５が形成され、ミセル内部に貴金属イオン水溶液が内包される。貴金属イオン水溶液に代えて不溶化剤水溶液を使用すると、図３（Ｂ）に示す不溶化剤水溶液を内包するミセル６が生成される。この両逆ミセル溶液を混合すると、逆ミセル同士が結合してミセル内で不溶化剤反応が進行し（図３（ｃ））、さらに不溶化剤粒子７を熟成するとミセルサイズによって制御されたコロイド状の貴金属を含有するミセル８を得ることができる（図３（Ｄ））。ミセル内部では貴金属の超微粒子の分散性に優れ、二種以上の貴金属イオンを含有させた場合にも極めて均一な組成の貴金属超微粒子が得られる。 For example, when a noble metal ion insolubilizing agent is added to a reverse micelle solution containing a noble metal ion aqueous solution inside the micelle, the noble metal ion is insolubilized in the noble metal inside the micelle and becomes colloidal noble metal particles. The insolubilizing agent for the noble metal ions may be added as an aqueous solution or as a reverse micelle solution containing the insolubilizing agent inside the micelle. FIG. 3 schematically shows the case where the insolubilizing agent is added as a reverse micelle solution. First, as shown in FIG. 3A, when a surfactant 2 is mixed in an organic solvent 1 and a noble metal ion aqueous solution is added thereto, a micelle 5 having a hydrophilic group 3 on the inside and a hydrophobic group 4 on the outside. And the aqueous noble metal ion solution is encapsulated inside the micelle. When an insolubilizing agent aqueous solution is used instead of the noble metal ion aqueous solution, micelles 6 containing the insolubilizing agent aqueous solution shown in FIG. 3B are generated. When the two reverse micelle solutions are mixed, the reverse micelles are bonded to each other and the insolubilizer reaction proceeds in the micelle (FIG. 3C). When the insolubilizer particles 7 are further aged, the colloidal shape controlled by the micelle size is obtained. A micelle 8 containing a noble metal can be obtained (FIG. 3D). Noble metal ultrafine particles are excellent in dispersibility of noble metal ultrafine particles inside the micelle, and even when two or more kinds of noble metal ions are contained, noble metal ultrafine particles having an extremely uniform composition can be obtained.
本発明における貴金属イオンとは、白金、パラジウム、ロジウム、オスミウム、ルテニウム及びイリジウムからなる群より選ばれる少なくとも一種の貴金属イオンである。これらの中でも、白金、パラジウムを使用することが好ましい。触媒活性に優れるからである。これらのイオンの供給源としては特に制限されず広くこれらのイオンを含有する化合物を使用することができる。このような化合物としては、上記貴金属の硝酸塩、硫酸塩、塩化物、アンミン錯体などが例示でき、これらを溶解する溶媒の種類やｐＨなどによって適宜選択することができる。これらの中でも、工業的に使用するには硝酸塩、硫酸塩、塩化物、アンミン錯体などが好ましい。これらの貴金属イオン濃度は、金属換算で０．１〜５０質量％であることが好ましく、より好ましくは０．５〜２０質量％である。 The noble metal ion in the present invention is at least one kind of noble metal ion selected from the group consisting of platinum, palladium, rhodium, osmium, ruthenium and iridium. Among these, it is preferable to use platinum and palladium. This is because the catalyst activity is excellent. The source of these ions is not particularly limited, and compounds containing these ions can be used widely. Examples of such compounds include nitrates, sulfates, chlorides, and ammine complexes of the above-mentioned noble metals, which can be appropriately selected depending on the type and pH of the solvent for dissolving them. Among these, nitrates, sulfates, chlorides, ammine complexes and the like are preferable for industrial use. The concentration of these noble metal ions is preferably 0.1 to 50% by mass, more preferably 0.5 to 20% by mass in terms of metal.
本発明において「不溶化剤」とは、ミセル内部の貴金属イオンを貴金属粒子にできるものやミセル内部の卑金属イオンを水酸化物などに不溶化し、沈殿にできるものを広く使用できる。これらは、使用する貴金属や卑金属によって適宜選択することができる。例えば、貴金属と反応してミセル内で粒子を生成させる水素、ヒドラジン、ホウ素化水素ナトリウム等の還元剤や、卑金属と反応してミセル内で沈殿を発生させるアンモニア、アンモニウム塩水溶液、テトラメチルアンモニウムヒドロキシド、アルカリ及びアルカリ土類金属化合物の水溶液などの沈殿剤など挙げられる。 In the present invention, as the “insolubilizing agent”, those capable of converting the noble metal ions inside the micelles into noble metal particles and those capable of insolubilizing the base metal ions inside the micelles into hydroxide and the like can be widely used. These can be appropriately selected depending on the noble metal or base metal used. For example, reducing agents such as hydrogen, hydrazine and sodium borohydride that react with precious metals to produce particles in micelles, ammonia that react with base metals to generate precipitates in micelles, aqueous ammonium salt solutions, tetramethylammonium hydroxy And precipitation agents such as aqueous solutions of alkali, alkaline earth metal compounds.
具体的には、貴金属イオンの還元剤としては、水素、ヒドラジン、ホウ素化水素ナトリウム、チオ硫酸ナトリウム、クエン酸、クエン酸ナトリウム、Ｌ−アスコルビン酸、水素化ホウ素ナトリウム、ホルムアルデヒド、メタノール、エタノール、エチレン、一酸化炭素等が挙げられる。ヒドラジン等の水溶液として調製し得るものは、濃度０．１〜４０質量％の水溶液として直接逆ミセル溶液に添加してもよいが、該溶液を用いて逆ミセル溶液を調製し、逆ミセル溶液（Ａ）に添加してもよい。濃度０．１〜４０質量％の水溶液であれば、ミセル内で貴金属イオンが貴金属粒子となった場合でもコロイド状にミセル内に分散できる。なお、ホウ素化水素ナトリウムなどの粉末状の物質は、そのまま供給することができる。水素などの常温でガス状の物質は、バブリングで供給することもできる。 Specifically, as a reducing agent for noble metal ions, hydrogen, hydrazine, sodium borohydride, sodium thiosulfate, citric acid, sodium citrate, L-ascorbic acid, sodium borohydride, formaldehyde, methanol, ethanol, ethylene And carbon monoxide. What can be prepared as an aqueous solution of hydrazine or the like may be directly added to the reverse micelle solution as an aqueous solution having a concentration of 0.1 to 40% by mass. However, a reverse micelle solution is prepared using the solution, and the reverse micelle solution ( It may be added to A). If the aqueous solution has a concentration of 0.1 to 40% by mass, it can be colloidally dispersed in the micelle even when the noble metal ion becomes noble metal particles in the micelle. Note that a powdered substance such as sodium borohydride can be supplied as it is. A gaseous substance at room temperature such as hydrogen can be supplied by bubbling.
本発明のナノハニカム触媒は、上記貴金属粒子に加えて、更に卑金属粒子をナノハニカム上に担持させたものであってもよい。例えば、ミセル内部に貴金属イオン水溶液を含有する逆ミセル溶液（Ａ）と、ミセル内部に卑金属イオン水溶液を含有する逆ミセル溶液（Ｂ）とを混合し、該混合溶液に該貴金属イオンの還元剤および／または該卑金属イオンの沈殿剤を添加して形成した平均粒子径１〜１０ｎｍ、より好ましくは２〜７ｎｍの合金粒子である。これを図４に模式的に示す。 The nano honeycomb catalyst of the present invention may be one in which base metal particles are further supported on the nano honeycomb in addition to the noble metal particles. For example, a reverse micelle solution (A) containing a noble metal ion aqueous solution inside the micelle and a reverse micelle solution (B) containing a base metal ion aqueous solution inside the micelle are mixed, and the noble metal ion reducing agent and And / or alloy particles having an average particle diameter of 1 to 10 nm, more preferably 2 to 7 nm, formed by adding a precipitant of the base metal ions. This is schematically shown in FIG.
図４（Ａ）は、ミセル内部に貴金属イオン水溶液を含有する逆ミセル溶液（Ａ）であり、図４（Ｂ）は、ミセル内部に卑金属イオン水溶液を含有する逆ミセル溶液（Ｂ）である。両ミセル溶液を混合すると、ミセル同士が結合して、均一な組成のミセル７を得ることができる（図４（Ｃ））。該溶液に、ミセル８の内部に貴金属イオンの還元剤水溶液を含有する逆ミセル溶液（図４（Ｄ））を添加すると、ミセル同士が結合して、ミセル中において還元反応が進行し（図４（Ｅ））。さらに、貴金属粒子９の熟成を行うと、図４（Ｆ）に示すようにミセルサイズで制御された貴金属粒子を含有するミセル１０を得ることができる。これに、ミセル１１内部に卑金属イオンの沈殿剤の水溶液を含む逆ミセル溶液（図４（Ｇ））を添加すると、ミセル同士が結合して、ミセル中で沈殿反応が進行し、さらに、沈殿の熟成を行うと図４（Ｈ）に示すように、ミセルサイズで制御された貴金属粒子と卑金属粒子との複合貴金属粒子を含有したミセル１２を得ることができる。該方法によれば、貴金属粒子と卑金属粒子との複合粒子の場合も、平均粒子径を１〜１０ｎｍ内に制御することができ、担体表面に均一に分散する金属粒子を有する電極触媒となる。 4A is a reverse micelle solution (A) containing a noble metal ion aqueous solution inside the micelle, and FIG. 4B is a reverse micelle solution (B) containing a base metal ion aqueous solution inside the micelle. When both micelle solutions are mixed, the micelles are bonded to each other to obtain a micelle 7 having a uniform composition (FIG. 4C). When a reverse micelle solution containing a reducing agent aqueous solution of noble metal ions is added to the inside of the micelle 8 (FIG. 4D), the micelles are bonded to each other and a reduction reaction proceeds in the micelle (FIG. 4). (E)). Furthermore, when the precious metal particles 9 are aged, micelles 10 containing precious metal particles controlled by the micelle size can be obtained as shown in FIG. 4 (F). When a reverse micelle solution containing an aqueous solution of a precipitating agent for base metal ions is added to the inside of the micelle 11 (FIG. 4 (G)), the micelles are bonded to each other, and the precipitation reaction proceeds in the micelle. When aged, as shown in FIG. 4 (H), micelles 12 containing composite noble metal particles of noble metal particles and base metal particles controlled by micelle size can be obtained. According to this method, even in the case of composite particles of noble metal particles and base metal particles, the average particle diameter can be controlled within 1 to 10 nm, and an electrode catalyst having metal particles uniformly dispersed on the support surface is obtained.
なお、貴金属イオンの還元剤や卑金属の沈殿剤は、図４に示すように逆ミセル溶液として添加する必要はなく、これらの水溶液を直接添加してもよい。 It is not necessary to add a reducing agent for noble metal ions or a precipitating agent for base metals as a reverse micelle solution as shown in FIG. 4, and these aqueous solutions may be added directly.
卑金属イオンとは、セリウム、プラセオジウム、ジルコニウム、マンガン、鉄、コバルト、ニッケル及びバリウムからなる群より選ばれた少なくとも一種の卑金属イオンである。これらのイオンは、上記卑金属の硝酸塩、硫酸塩、アンモニウム塩、アミン、炭酸塩、重炭酸塩、ハロゲン塩、亜硝酸塩、蓚酸などの無機塩類、ギ酸塩などのカルボン酸塩および水酸化物、アルコキサイド、酸化物などが例示でき、これらを溶解する溶媒の種類やｐＨなどによって適宜選択することができる。 The base metal ion is at least one base metal ion selected from the group consisting of cerium, praseodymium, zirconium, manganese, iron, cobalt, nickel, and barium. These ions include nitrates, sulfates, ammonium salts, amines, carbonates, bicarbonates, halogen salts, nitrites, oxalic acid and other inorganic salts, carboxylates and hydroxides such as formate, alkoxides. And oxides can be exemplified, and can be appropriately selected depending on the type and pH of the solvent in which these are dissolved.
貴金属と卑金属との合金を使用することで、触媒活性を更に向上させることができる。特に卑金属を使用すると、質量活性（貴金属の単位重量当りの活性）の向上の点で有利である。 The catalytic activity can be further improved by using an alloy of a noble metal and a base metal. In particular, the use of a base metal is advantageous in terms of improving mass activity (activity per unit weight of noble metal).
なお、卑金属の沈殿剤としては、使用する卑金属に応じて適宜選択することができるが、本発明では、特に卑金属水酸化物を形成させて沈殿させるものであることが好ましい。該ナノハニカム触媒の触媒成分である貴金属は、白金酸化物などの酸化物となって担持されるよりも白金粒子で担持される方が触媒活性が高い。一方、貴金属と卑金属水酸化物とを担持したナノハニカムを焼成すると、焼成条件によっても異なるが、共に貴金属酸化物と卑金属酸化物とに変化する。しかしながら、卑金属水酸化物であれば焼成によって卑金属酸化物に変化するが貴金属の貴金属酸化物への酸化を抑止することができ、これによって触媒活性の低下を防止することができる。従って、卑金属の不溶化剤としては、卑金属の水酸化剤を使用することが好ましい。このような水酸化剤としては、アンモニウム塩水溶液、テトラメチルアンモニウムヒドロキシド、アルカリ及びアルカリ土類金属化合物の水溶液がある。アンモニア水、テトラメチルアンモニウムヒドロキシド等は、濃度０．１〜３０質量％の水溶液として直接逆ミセル溶液に添加してもよいが、該溶液を用いて逆ミセル溶液を調製して添加してもよい。なお、濃度０．１〜３０質量％の水溶液であれば、ミセル内で卑金属イオンが卑金属粒子となった場合でもコロイド状にミセル内に分散できる。 The base metal precipitating agent can be appropriately selected according to the base metal to be used, but in the present invention, it is particularly preferable that the base metal hydroxide is formed and precipitated. The noble metal that is the catalyst component of the nanohoneycomb catalyst has higher catalytic activity when supported by platinum particles than when supported by an oxide such as platinum oxide. On the other hand, when a nanohoneycomb carrying a noble metal and a base metal hydroxide is fired, both of them change to a noble metal oxide and a base metal oxide, depending on the firing conditions. However, if it is a base metal hydroxide, it will change into a base metal oxide by baking, but the oxidation of a noble metal to a noble metal oxide can be suppressed, and the fall of catalyst activity can be prevented by this. Therefore, it is preferable to use a base metal hydroxide as the base metal insolubilizer. Such hydroxylating agents include aqueous ammonium salt solutions, aqueous solutions of tetramethylammonium hydroxide, alkali and alkaline earth metal compounds. Ammonia water, tetramethylammonium hydroxide or the like may be added directly to the reverse micelle solution as an aqueous solution having a concentration of 0.1 to 30% by mass, but the reverse micelle solution may be prepared and added using the solution. Good. In addition, if it is aqueous solution with a density | concentration of 0.1-30 mass%, even when a base metal ion turns into a base metal particle in a micelle, it can disperse | distribute in a micelle colloidally.
本発明のナノハニカム触媒は、貴金属イオン含有溶液が逆ミセル溶液として添加されるが、ミセルのサイズは、使用する溶媒や界面活性剤の種類、添加量によって調整することができ、例えばミセルの直径が２０〜１００ｎｍの逆ミセル溶液をナノハニカムに塗布しまたは含浸すると、該ナノハニカム表面にミセルが均等に付着し（図５（Ａ））、該ナノハニカムを焼成すると、隣接する金属粒子間に１０〜５０ｎｍの間隔で担体表面に均一に担持させた電極触媒を得ることができる（図５（Ｂ））。従来法では、白金や白金合金の凝集が発生し、粒子径や粒子分布を制御することが困難であったが、本発明によればこれらの制御が極めて簡便かつ確実に行える。 In the nanohoneycomb catalyst of the present invention, the noble metal ion-containing solution is added as a reverse micelle solution. When a reverse micelle solution having a thickness of 20 to 100 nm is applied to or impregnated into the nanohoneycomb, the micelles uniformly adhere to the nanohoneycomb surface (FIG. 5A), and when the nanohoneycomb is fired, between the adjacent metal particles An electrode catalyst uniformly supported on the support surface at intervals of 10 to 50 nm can be obtained (FIG. 5B). In the conventional method, agglomeration of platinum or a platinum alloy occurs, and it is difficult to control the particle diameter and particle distribution. However, according to the present invention, these controls can be performed very simply and reliably.
なお、逆ミセル溶液（Ａ）、逆ミセル溶液（Ｂ）、還元剤、沈殿剤の添加順序は、逆ミセル（Ａ）に還元剤を添加すると貴金属イオンが貴金属粒子となり、逆ミセル溶液（Ｂ）に沈殿剤を添加すると卑金属イオンが卑金属粒子となることから、（ｉ）逆ミセル溶液（Ａ）に還元剤を添加し、これに逆ミセル溶液（Ｂ）を添加し、次いで沈殿剤を添加する方法のほか、（ｉｉ）逆ミセル溶液（Ａ）と逆ミセル溶液（Ｂ）との混合溶液に、還元剤を先に添加し、後から沈殿剤を添加する方法、（ｉｉｉ）逆ミセル溶液（Ａ）と逆ミセル溶液（Ｂ）との混合溶液に、先に沈殿剤を添加し、後から還元剤を添加する方法、（ｉｖ）逆ミセル溶液（Ｂ）に、沈殿剤を添加し、次いで逆ミセル溶液（Ａ）を添加し、更に還元剤を添加する方法などのいずれであってもよい。なお、逆ミセル溶液（Ａ）に該担体を添加した後、メタノールやエタノールなどのアルコール類を添加してミセルを破壊し、貴金属粒子が担体表面に担持されるのを促進することもできる。 The reverse micelle solution (A), reverse micelle solution (B), reducing agent, and precipitating agent are added in the order of noble metal ions when the reducing agent is added to the reverse micelle (A), and the reverse micelle solution (B). (I) Add a reducing agent to the reverse micelle solution (A), add the reverse micelle solution (B), and then add the precipitant. In addition to the method, (ii) a method in which a reducing agent is first added to a mixed solution of the reverse micelle solution (A) and the reverse micelle solution (B), and then a precipitant is added; (iii) a reverse micelle solution ( A method in which a precipitant is first added to a mixed solution of A) and reverse micelle solution (B), and then a reducing agent is added; (iv) a precipitant is added to reverse micelle solution (B); Any method including adding reverse micelle solution (A) and further adding reducing agent It may be. In addition, after adding this support | carrier to reverse micelle solution (A), alcohols, such as methanol and ethanol, can also be added, a micelle can be destroyed and it can accelerate | stimulate that a noble metal particle is carry | supported on the support | carrier surface.
本発明では次いで、このように貴金属や卑金属を担持したナノハニカムに、担体成分アルコキシド溶液あるいは担体成分アルコキシドの加水分解物を含む逆ミセル溶液（Ｃ）を添加することを特徴とする。一般に、アルコキシドとは、アルコール類の水酸基を金属または非金属で置換した化合物である。本発明ではこのような金属や非金属が担体成分となり得る場合のアルコキシドを担体成分アルコキシドという。アルコキシドに含まれる金属や非金属、すなわち担体成分としては、アルミニウム、シリコン、チタニウム、セリウム、ジルコニウム、およびタングステンから選ばれる少なくとも一種がある。従って、これらの担体成分アルコキシドとしては、アルミニウムアルコキシド、シリコンアルコキシド、チタニウムアルコキシド、セリウムアルコキシド、ジルコニウムアルコキシド、およびタングステンアルコキシドがある。具体的には、アルミニウムテトラエトキシド、アルミニウムイソプロポキシド、アルミニウムテトラブトキシド等のアルミニウムアルコキシド；シリコンテトラエトキシド、シリコンテトライソプロポキシド、シリコンテトラブトキシド等のシリコンアルコキシド；シリコンテトラエトキシド、シリコンテトライソプロポキシド、シリコンテトラブトキシド等のシリコンアルコキシド；チタニウムテトラエトキシド、チタニウムテトライソプロポキシド、チタニウムテトラブトキシド等のチタニウムアルコキシド；セリウムテトラエトキシド、セリウムテトライソプロポキシド、セリウムテトラブトキシド等のセリウムアルコキシド；ジルコニウムテトラエトキシド、ジルコニウムテトライソプロポキシド、ジルコニウムテトラブトキシド等のジルコニウムアルコキシド；タングステンテトラエトキシド、タングステンテトライソプロポキシド、タングステンテトラブトキシド等のゲルマニウムアルコキシドがある。 Next, the present invention is characterized in that the carrier component alkoxide solution or the reverse micelle solution (C) containing the hydrolyzate of the carrier component alkoxide is added to the nanohoneycomb supporting the noble metal or the base metal. In general, an alkoxide is a compound in which a hydroxyl group of an alcohol is substituted with a metal or a nonmetal. In the present invention, an alkoxide in the case where such a metal or nonmetal can serve as a carrier component is referred to as a carrier component alkoxide. As the metal or nonmetal contained in the alkoxide, that is, the carrier component, there is at least one selected from aluminum, silicon, titanium, cerium, zirconium, and tungsten. Accordingly, these carrier component alkoxides include aluminum alkoxide, silicon alkoxide, titanium alkoxide, cerium alkoxide, zirconium alkoxide, and tungsten alkoxide. Specifically, aluminum alkoxide such as aluminum tetraethoxide, aluminum isopropoxide, aluminum tetrabutoxide; silicon alkoxide such as silicon tetraethoxide, silicon tetraisopropoxide, silicon tetrabutoxide; silicon tetraethoxide, silicon tetraiso Silicon alkoxides such as propoxide and silicon tetrabutoxide; titanium alkoxides such as titanium tetraethoxide, titanium tetraisopropoxide and titanium tetrabutoxide; cerium alkoxides such as cerium tetraethoxide, cerium tetraisopropoxide and cerium tetrabutoxide; zirconium Tetraethoxide, zirconium tetraisopropoxide, zirconium tetrabutoxide, etc. Zirconium alkoxide; tungsten tetraethoxide, tungsten tetraisopropoxide, there germanium alkoxides such as tungsten tetrabutoxide.
このような担体成分アルコキシドは加水分解によって水溶性の水酸化物となるが、担体成分アルコキシド自体はアルコキシドの存在によって親油性であり、逆ミセル溶液と優れた親和性を有する。従って、逆ミセル溶液を用いてナノハニカムに貴金属や卑金属を担持した後に担体成分アルコキシドを添加すると、ハニカム表面に存在する逆ミセル溶液の溶媒と親和して均一に分散し、次いでこれを加水分解すれば水酸化アルミニウムが薄層に塗布され、これを焼成すると水酸化アルミニウムがアルミナとなって貴金属や卑金属の担体として作用する。 Such a carrier component alkoxide becomes a water-soluble hydroxide by hydrolysis, but the carrier component alkoxide itself is lipophilic due to the presence of the alkoxide and has an excellent affinity for the reverse micelle solution. Therefore, when the support component alkoxide is added after supporting the noble metal or base metal on the nanohoneycomb using the reverse micelle solution, it is uniformly dispersed in affinity with the solvent of the reverse micelle solution present on the honeycomb surface, and then hydrolyzed. For example, aluminum hydroxide is applied to a thin layer, and when this is fired, the aluminum hydroxide becomes alumina and acts as a support for a noble metal or base metal.
このような担体成分アルコキシドは、溶媒に溶解して塗布することが好ましく、このような溶媒としては、シクロヘキサン、メチルシクロヘキサン、シクロヘプタン、ヘプタノール、オクタノール、ドデシルアルコール、セチルアルコール、イソオクタン、ｎ−ヘプタン、ｎ−ヘキサン、ｎ−デカン、ベンゼン、トルエン、キシレン等がある。 Such a carrier component alkoxide is preferably applied after being dissolved in a solvent, such as cyclohexane, methylcyclohexane, cycloheptane, heptanol, octanol, dodecyl alcohol, cetyl alcohol, isooctane, n-heptane, There are n-hexane, n-decane, benzene, toluene, xylene and the like.
また、担体成分アルコキシドの加水分解は、逆ミセル内に含有される水（可溶化水）によって起こり、更に加水分解反応を促進するためアンモニア水を添加しても良い。 In addition, hydrolysis of the carrier component alkoxide is caused by water (solubilized water) contained in the reverse micelle, and ammonia water may be added to further promote the hydrolysis reaction.
なお、担体成分として担体成分アルコキシドを使用する利点は、それ自体がナノハニカム細孔内の逆ミセルに含まれる水を利用して加水分解するからである。 The advantage of using the carrier component alkoxide as the carrier component is that it itself hydrolyzes using water contained in the reverse micelles in the nanohoneycomb pores.
本発明において、逆ミセルの形成に利用可能な有機溶媒としては様々な物質が使用可能であるが、一例を挙げると、シクロヘキサン、メチルシクロヘキサン、シクロヘプタン、ヘプタノール、オクタノール、ドデシルアルコール、セチルアルコール、イソオクタン、ｎ−ヘプタン、ｎ−ヘキサン、ｎ−デカン、ベンゼン、トルエン、キシレン等がある。また、逆ミセル溶液中の水滴の大きさを調節する目的で、アルコール等を添加してもよい。該有機溶媒は、１種を単独で使用するほか、２種以上を併用することもできる。更に、逆ミセル溶液（Ａ）にも逆ミセル溶液（Ｂ）の調製にも使用することができ、更に貴金属イオンの還元剤や卑金属イオンの沈殿剤を逆ミセル溶液として供給する場合には、これらの溶液の調製にも使用することができる。この際、いずれかの逆ミセル溶液に使用する有機溶媒と他の逆ミセル溶液に使用する有機溶媒とは、同種のものであっても異種のものであってもよい。 In the present invention, various substances can be used as organic solvents that can be used for forming reverse micelles. For example, cyclohexane, methylcyclohexane, cycloheptane, heptanol, octanol, dodecyl alcohol, cetyl alcohol, isooctane. N-heptane, n-hexane, n-decane, benzene, toluene, xylene and the like. Moreover, you may add alcohol etc. in order to adjust the magnitude | size of the water droplet in a reverse micelle solution. The organic solvent can be used alone or in combination of two or more. Furthermore, it can be used for the preparation of reverse micelle solution (A) and reverse micelle solution (B), and when supplying a precious metal ion reducing agent or base metal ion precipitating agent as a reverse micelle solution, It can also be used for the preparation of solutions. At this time, the organic solvent used for any of the reverse micelle solutions and the organic solvent used for the other reverse micelle solutions may be the same or different.
逆ミセル溶液を形成する界面活性剤としては、ポリオキシエチレンノニルフェニルエーテル、ラウリン酸マグネシウム、カプリン酸亜鉛、ミリスチン酸亜鉛、ナトリウムフェニルステアレ−ト、アルミニウムジカプリレ−ト、テトライソアミルアンモニウムチオシアネ−ト、ｎ−オクタデシルトリｎ−ブチルアンモニウム蟻酸塩、ｎ−アミルトリｎ−ブチルアンモニウムヨウ化物、ナトリウムビス（２−エチルヘキシル）琥珀酸塩、ナトリウムジノニルナフタレンスルホネ−ト、カルシウムセチルサルフェート、ドデシルアミンオレイン酸塩、ドデシルアミンプロピオン酸塩、セチルトリメチルアンモニウムブロマイド、ステアリルトリメチルアンムニウムブロマイド、セチルトリメチルアンモニウムクロライド、ステアリルトリメチルアンモニウムクロライド、ドデシルトリメチルアンモニウムブロマイド、オクタデシルトリメチルアンモニウムブロマイド、ドデシルトリメチルアンモニウムクロライド、オクタデシルトリメチルアンモニウムクロライド、ジドデシルジメチルアンモニウムブロマイド、ジテトラデシルジメチルアンモニウムブロマイド、ジドデシルジメチルアンモニウムクロライド、ジテトラデシルジメチルアンモニウムクロライド、（２−オクチルオキシ−１−オクチルオキシメチル）ポリオキシエチレンエチルエーテル等を挙げることができる。該界面活性剤も、いずれの逆ミセル溶液の調製にも使用することができ、２種以上を併用することもできる。なお、有機溶媒に対する界面活性剤の添加量は、有機溶媒１００質量部に対して、１０〜３００質量である。１０質量部を下回ると逆ミセルの形成が困難となり、一方３００質量部を超えるとロッド状ミセルが形成され、貴金属粒子径を特定の大きさに制御し凝集させないと云う観点で不利である。 Surfactants that form reverse micelle solutions include polyoxyethylene nonylphenyl ether, magnesium laurate, zinc caprate, zinc myristate, sodium phenyl stearate, aluminum dicaprylate, tetraisoamylammonium thiocyanate. Net, n-octadecyltri-n-butylammonium formate, n-amyltri-n-butylammonium iodide, sodium bis (2-ethylhexyl) succinate, sodium dinonylnaphthalenesulfonate, calcium cetyl sulfate, dodecyl Amine oleate, dodecylamine propionate, cetyltrimethylammonium bromide, stearyltrimethylammonium bromide, cetyltrimethylammonium chloride, stearyltrimethylan Nium chloride, dodecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, didodecyldimethylammonium bromide, ditetradecyldimethylammonium bromide, didodecyldimethylammonium chloride, ditetradecyldimethylammonium chloride, ( 2-octyloxy-1-octyloxymethyl) polyoxyethylene ethyl ether and the like. The surfactant can also be used for the preparation of any reverse micelle solution, and two or more kinds can be used in combination. In addition, the addition amount of surfactant with respect to an organic solvent is 10-300 mass with respect to 100 mass parts of organic solvents. If the amount is less than 10 parts by mass, it is difficult to form reverse micelles. On the other hand, if the amount exceeds 300 parts by mass, rod-like micelles are formed, which is disadvantageous in that the noble metal particle diameter is controlled to a specific size to prevent aggregation.
触媒成分の担持後のナノハニカムには逆ミセル溶液の溶媒や界面活性剤が残存するため、焼成前にこれを洗浄し、乾燥した後に焼成することが好ましい。洗浄方法としては、溶媒として、前記有機溶媒等を使用し、洗浄処理を行う。 Since the solvent and the surfactant of the reverse micelle solution remain in the nanohoneycomb after supporting the catalyst component, it is preferable to wash this before firing and to fire after drying. As a cleaning method, the organic solvent or the like is used as a solvent to perform a cleaning process.
次いで該ナノハニカムを乾燥する。乾燥方法は、例えば自然乾燥、蒸発乾固法、ロータリーエバポレーター、噴霧乾燥機、ドラムドライヤーによる乾燥などを用いることができる。乾燥時間は、使用する方法に応じて適宜選択すればよい。場合によっては、乾燥工程を行わずに、焼成工程において乾燥させることとしてもよい。 The nanohoneycomb is then dried. As the drying method, for example, natural drying, evaporation to dryness, rotary evaporator, spray dryer, drying with a drum dryer, or the like can be used. What is necessary is just to select drying time suitably according to the method to be used. Depending on the case, it is good also as drying in a baking process, without performing a drying process.
また、加熱や焼成は、不活性ガス雰囲気下で４００℃〜１０００℃、より好ましくは６００〜８００℃で行うことが好ましい。反応原料や目的物によって異なるが、貴金属の酸化物よりも還元状態の貴金属の方が触媒活性が高い場合があり、このような場合には、アルゴンや窒素等の不活性（非酸化性）雰囲気下において加熱・焼成することで、貴金属の過剰な酸化を防止することができる。 Moreover, it is preferable to perform a heating and baking by 400 to 1000 degreeC by an inert gas atmosphere, More preferably, it is 600 to 800 degreeC. Although it varies depending on the reaction raw material and the target product, the catalytic activity of the noble metal in the reduced state may be higher than the oxide of the noble metal. In such a case, an inert (non-oxidizing) atmosphere such as argon or nitrogen By heating and baking at the bottom, excessive oxidation of the noble metal can be prevented.
本発明のナノハニカム触媒は、排気ガス浄化触媒、燃料電池用電極触媒、コージェネ用排ガス浄化触媒などとして好適である。特に、ナノハニカムに高分散して貴金属、卑金属及び担体成分が担持されており、触媒活性に優れる。特に、焼成することで貴金属粒子または貴金属と卑金属との合金粒子を得ることができ、該金属粒子のＰｔ（ＩＩＩ）結晶面の成長を促進することで、高い酸素還元活性を得る事ができる。 The nanohoneycomb catalyst of the present invention is suitable as an exhaust gas purification catalyst, a fuel cell electrode catalyst, a cogeneration exhaust gas purification catalyst, and the like. In particular, it is highly dispersed in the nanohoneycomb and carries noble metals, base metals and carrier components, and is excellent in catalytic activity. In particular, noble metal particles or alloy particles of noble metal and base metal can be obtained by firing, and high oxygen reduction activity can be obtained by promoting the growth of the Pt (III) crystal plane of the metal particles.
また、本発明によるナノハニカム触媒の製造方法は、逆ミセル溶液を用いて貴金属や卑金属を担持するため、これら金属の粒子径の調整が容易であり、かつより微粒子を均一に分散させることができる。しかも、不溶化剤を選択することで卑金属の沈殿物を特定の化合物に変化させることができ、このため触媒活性やその他、耐熱性等を調整することができる。更に、貴金属担持後に担体成分アルコキシドを添加し、その後に加水分解することでナノハニカムに薄層に担体成分を担持させることができる。該方法によれば、従来困難であったナノハニカムへの微細な触媒成分の高分散担持を容易に行うことができる。 Further, the method for producing a nanohoneycomb catalyst according to the present invention supports a noble metal or a base metal using a reverse micelle solution, so that the particle diameter of these metals can be easily adjusted, and fine particles can be more uniformly dispersed. . In addition, the base metal precipitate can be changed to a specific compound by selecting an insolubilizing agent, so that the catalyst activity, heat resistance, and the like can be adjusted. Furthermore, the carrier component alkoxide is added after supporting the noble metal, and then the carrier component is supported in a thin layer on the nanohoneycomb by hydrolysis. According to this method, it is possible to easily carry a high dispersion of fine catalyst components on the nanohoneycomb, which has been difficult in the past.
以下、本発明を実施例に基づいて具体的に説明する。なお、本発明は、これらの実施例のみに限定されることはない。 Hereinafter, the present invention will be specifically described based on examples. In addition, this invention is not limited only to these Examples.
（実施例１）
界面活性剤としてポリオキシエチレン（５）ノニルフェニルエーテル４４ｇを用い、シクロへキサンを加えて１．０Ｌ（０．１ｍｏｌ／Ｌ）とし、界面活性剤が溶解・混合するまで撹拌した。これにジニトロジアンミン白金水溶液（Ｐｔ濃度８．０質量％）１０．０ｇを加えて透明になるまで１時間攪拌して逆ミセル溶液Ａを調製した。
(Example 1)
Using 44 g of polyoxyethylene (5) nonylphenyl ether as a surfactant, cyclohexane was added to 1.0 L (0.1 mol / L), and the mixture was stirred until the surfactant was dissolved and mixed. To this, 10.0 g of dinitrodiammine platinum aqueous solution (Pt concentration 8.0 mass%) was added and stirred for 1 hour until it became transparent to prepare reverse micelle solution A.
界面活性剤としてポリオキシエチレン（５）ノニルフェニルエーテル４４ｇを用い、シクロへキサンを加えて１．０Ｌ（０．１ｍｏｌ／Ｌ）とし、界面活性剤が溶解・混合するまで撹拌した。これに濃度０．５質量％のヒドラジン水溶液１３．２ｇ（Ｐｔの１／２倍モル量）を加えて１時間攪拌して逆ミセル溶液Ｂを調製した。 Using 44 g of polyoxyethylene (5) nonylphenyl ether as a surfactant, cyclohexane was added to 1.0 L (0.1 mol / L), and the mixture was stirred until the surfactant was dissolved and mixed. A reverse micelle solution B was prepared by adding 13.2 g of a hydrazine aqueous solution having a concentration of 0.5% by mass (1/2 molar amount of Pt) and stirring for 1 hour.
界面活性剤としてポリオキシエチレン（５）ノニルフェニルエーテル４４ｇを用い、シクロへキサンを加えて１．０Ｌ（０．１ｍｏｌ／Ｌ）とし、界面活性剤が溶解・混合するまで撹拌した。これにアンモニア水溶液（濃度１．０質量％）２８．４ｇを加えて透明になるまで１時間攪拌し、逆ミセル溶液Ｃを調製した。 Using 44 g of polyoxyethylene (5) nonylphenyl ether as a surfactant, cyclohexane was added to 1.0 L (0.1 mol / L), and the mixture was stirred until the surfactant was dissolved and mixed. To this was added 28.4 g of an aqueous ammonia solution (concentration: 1.0% by mass) and the mixture was stirred for 1 hour until it became transparent to prepare reverse micelle solution C.
界面活性剤としてポリオキシエチレン（５）ノニルフェニルエーテル４４ｇを用い、シクロへキサンを加えて１．０Ｌ（０．１ｍｏｌ／Ｌ）とし、界面活性剤が溶解・混合するまで撹拌した。これにオキシ硝酸ジルコニウム（ＺｒＯ（ＮＯ３）２・２Ｈ２Ｏ）水溶液（オキシ硝酸ジルコニウム濃度１０質量％）１１．０ｇ硝酸セリウム（Ｃｅ（ＮＯ３）３・６Ｈ２Ｏ）１０％水溶液１７．８ｇを加えて透明になるまで、１時間攪拌し、逆ミセル溶液Ｄを得た。このときのＷ／Ｏ値はそれぞれ２から２０程度に調整した。なお、Ｗ／Ｏ値は、界面活性剤１モルに対する液滴のモル数である。 Using 44 g of polyoxyethylene (5) nonylphenyl ether as a surfactant, cyclohexane was added to 1.0 L (0.1 mol / L), and the mixture was stirred until the surfactant was dissolved and mixed. This zirconium oxynitrate (ZrO (NO 3) 2 · 2H 2 O) aqueous solution (oxy zirconium concentration of 10 mass%) 11.0 g of cerium nitrate (Ce (NO 3) 3 · 6H 2 O) 10% aqueous solution of 17.8g Was added and the mixture was stirred for 1 hour until transparent, and reverse micelle solution D was obtained. The W / O value at this time was adjusted to about 2 to 20 respectively. The W / O value is the number of moles of droplets per mole of surfactant.
次いで、逆ミセル溶液Ａを撹拌しながら逆ミセル溶液Ｂを加え、１時間攪拌した後に白金粒子を逆ミセル中に含む溶液１を得た。また、逆ミセル溶液Ｄを撹拌しながら逆ミセル溶液Ｃを加え、１時間攪拌した後、ジルコニア−セリア前駆体を逆ミセル中に含む溶液２を得た。 Next, reverse micelle solution B was added while stirring reverse micelle solution A, and after stirring for 1 hour, solution 1 containing platinum particles in reverse micelles was obtained. Moreover, after stirring reverse micelle solution D, reverse micelle solution C was added and stirred for 1 hour, and then solution 2 containing zirconia-ceria precursor in reverse micelles was obtained.
溶液１を撹拌しながら溶液２を加え、１時間攪拌した後に白金粒子とジルコニア−セリア前駆体を逆ミセル中に含む溶液３を得た。 Solution 2 was added while stirring Solution 1, and after stirring for 1 hour, Solution 3 containing platinum particles and a zirconia-ceria precursor in reverse micelles was obtained.
この溶液３をメタル箔表面のアルミニウム質ナノハニカム（一辺が５００ｎｍの四角形のナノハニカム、セル数４００個／インチ２に相当、容量１０００ｃｃ）中に充填した後、アルミニウムイソプロポキシド溶解シクロヘキサン溶液を加え、アルミニウム質ナノハニカム中で担体成分アルコキシドの加水分解反応を充分に進行するため、２４時間撹拌・熟成した。この操作を数回繰り返し、アルミニウム質ナノハニカム内を白金粒子とジルコニア−セリア前駆体（水酸化物）を含むアルミニウム水酸化物を所定量付着させた。 Aluminum quality nano honeycomb of this solution 3 metal foil surface (one side 500nm square nano honeycomb, corresponds to the number of cells 400 cells / inch 2, capacity 1000 cc) was filled in an aluminum isopropoxide dissolved cyclohexane solution added In order to sufficiently proceed the hydrolysis reaction of the carrier component alkoxide in the aluminum nanohoneycomb, it was stirred and aged for 24 hours. This operation was repeated several times to deposit a predetermined amount of aluminum hydroxide containing platinum particles and a zirconia-ceria precursor (hydroxide) inside the aluminum nanohoneycomb.
エタノール及び水で界面活性剤及び溶媒を洗浄した後、減圧下８５℃において１２時間乾燥し、さらに、不活性ガス流通雰囲気下、４００℃、２時間焼成し、さらに空気流通雰囲気下６００℃、５時間焼成して触媒層を形成し、Ｐｔ担持量１．５ｇ／Ｌの触媒を得た。 The surfactant and solvent were washed with ethanol and water, dried at 85 ° C. under reduced pressure for 12 hours, further baked in an inert gas flow atmosphere at 400 ° C. for 2 hours, and further in an air flow atmosphere at 600 ° C., 5 ° C. A catalyst layer was formed by calcining for a period of time to obtain a catalyst having a Pt loading of 1.5 g / L.
（比較例１）
Ｐｔ（５質量％）担持アルミナ粉末５００ｇとジルコニア−セリア複合酸化物粉末５００ｇと純水１０００ｇを、混合した後、ボールミルで粉砕し調製したスラリーを、メタル箔表面にアルミニウム質ナノハニカムを有すメタル担体に所定量塗布した。次いで、１２０℃において１２時間乾燥し、さらに、空気流通雰囲気下、４００℃，２時間焼成し、さらに６００℃、５時間焼成して触媒を形成し、Ｐｔ担持量１．５ｇ／Ｌの触媒を得た。
(Comparative Example 1)
Metal having aluminum nano-honeycomb on the metal foil surface after mixing 500 g of Pt (5% by mass) supported alumina powder, 500 g of zirconia-ceria composite oxide powder and 1000 g of pure water and then pulverizing with a ball mill. A predetermined amount was applied to the carrier. Next, it is dried at 120 ° C. for 12 hours, further calcined in an air circulation atmosphere at 400 ° C. for 2 hours, and further calcined at 600 ° C. for 5 hours to form a catalyst. Obtained.
（触媒の特性評価）
触媒特性は、下記条件にて評価した。
(Characteristic evaluation of catalyst)
The catalyst characteristics were evaluated under the following conditions.
（１）耐久条件：
エンジン排気量；日産自動車株式会社製 直列４気筒 ２０００ｃｃ、
燃料；ガソリン（日石ダッシュ）、
触媒入口ガス温度；６５０℃、
耐久時間；５０時間。
(1) Endurance conditions:
Engine displacement: Nissan Motor Co., Ltd., inline 4-cylinder 2000cc,
Fuel: Gasoline (Nisseki Dash),
Catalyst inlet gas temperature: 650 ° C.
Endurance time: 50 hours.
（２）台上性能試験
エンジン排気量；日産自動車株式会社製 直列４気筒 ２０００ｃｃ、
空燃比；Ａ／Ｆ＝１４．７、
温度条件；昇温速度１０℃／分，触媒入口温度１００℃〜４５０℃。
(2) Bench performance test Engine displacement: In-line 4-cylinder 2000cc made by Nissan Motor Co., Ltd.
Air-fuel ratio; A / F = 14.7,
Temperature conditions: temperature rising rate 10 ° C./min, catalyst inlet temperature 100 ° C. to 450 ° C.
（結果）
表１に示す様に、５０％の転化率を獲得するための温度は、いずれも実施例１の方が比較例１よりも低く、実施例１で調製したナノハニカム触媒は、触媒活性に優れることが判明した。
(result)
As shown in Table 1, the temperature for obtaining a conversion rate of 50% is lower in Example 1 than in Comparative Example 1, and the nanohoneycomb catalyst prepared in Example 1 is excellent in catalytic activity. It has been found.
本発明のナノハニカム触媒は表面積が大きく、単位体積当たりの反応ガスとの接触面積が大きいため、装置をコンパクトにすることができる。また、貴金属や卑金属、担体成分が均一に高分散されるため、触媒活性が高い。本発明のナノハニカム触媒は、自動車などの搭載容量の制限された装置内でも極めて優れた触媒活性を発揮することができる。 Since the nano honeycomb catalyst of the present invention has a large surface area and a large contact area with the reaction gas per unit volume, the apparatus can be made compact. Further, since noble metals, base metals, and carrier components are uniformly and highly dispersed, the catalytic activity is high. The nanohoneycomb catalyst of the present invention can exhibit extremely excellent catalytic activity even in an apparatus having a limited mounting capacity such as an automobile.
１ 有機溶媒、
２ 界面活性剤、
３ 親水性基、
４ 疎水性基、
５ 親水性基を内側に疎水性基を外側にするミセル、
６ 還元剤水溶液を内包するミセル、
７ 還元粒子、
８ コロイド状の貴金属を含有するミセル、
９ 貴金属粒子、
１０ 貴金属粒子を含有するミセル、
１１ ミセル、
１２ ミセルサイズで制御された貴金属粒子と卑金属粒子との合金粒子を含有したミセル。
1 organic solvent,
2 surfactant,
3 hydrophilic groups,
4 hydrophobic groups,
5 A micelle with a hydrophilic group on the inside and a hydrophobic group on the outside,
6 micelles containing the reducing agent aqueous solution,
7 reduced particles,
8 micelles containing colloidal noble metals,
9 Precious metal particles,
10 micelles containing noble metal particles,
11 micelles,
12 A micelle containing alloy particles of noble metal particles and base metal particles controlled by micelle size.
Claims (17)
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007313500A (en) * | 2006-04-28 | 2007-12-06 | Nissan Motor Co Ltd | Catalyst for exhaust gas purification, and method for manufacturing this catalyst |
| WO2018151278A1 (en) * | 2017-02-17 | 2018-08-23 | 学校法人早稲田大学 | Manufacturing methods for supported catalyst and carbon nanostructure |
| WO2020195237A1 (en) | 2019-03-26 | 2020-10-01 | サクラ工業株式会社 | Catalyst layer forming material, catalyst device constituent material, catalyst device, and production methods thereof |
| WO2023093000A1 (en) * | 2021-11-29 | 2023-06-01 | 中国华能集团清洁能源技术研究院有限公司 | Hydrogenation catalyst, and preparation method therefor and use thereof |
-
2003
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007313500A (en) * | 2006-04-28 | 2007-12-06 | Nissan Motor Co Ltd | Catalyst for exhaust gas purification, and method for manufacturing this catalyst |
| WO2018151278A1 (en) * | 2017-02-17 | 2018-08-23 | 学校法人早稲田大学 | Manufacturing methods for supported catalyst and carbon nanostructure |
| JPWO2018151278A1 (en) * | 2017-02-17 | 2019-12-12 | 学校法人早稲田大学 | Supported catalyst and method for producing carbon nanostructure |
| JP7093971B2 (en) | 2017-02-17 | 2022-07-01 | 学校法人早稲田大学 | Method for manufacturing supported catalyst and carbon nanostructures |
| WO2020195237A1 (en) | 2019-03-26 | 2020-10-01 | サクラ工業株式会社 | Catalyst layer forming material, catalyst device constituent material, catalyst device, and production methods thereof |
| US11867109B2 (en) | 2019-03-26 | 2024-01-09 | Sakura Kogyo Co., Ltd. | Catalyst layer forming material, catalyst apparatus constituent material, catalyst apparatus, and methods for manufacturing the same |
| WO2023093000A1 (en) * | 2021-11-29 | 2023-06-01 | 中国华能集团清洁能源技术研究院有限公司 | Hydrogenation catalyst, and preparation method therefor and use thereof |
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