JP2615418B2 - Oxidation catalyst, reduction catalyst, flammable gas sensor element and catalyst for electrode made of titanium-based metal oxide immobilized with ultrafine gold particles - Google Patents
Oxidation catalyst, reduction catalyst, flammable gas sensor element and catalyst for electrode made of titanium-based metal oxide immobilized with ultrafine gold particlesInfo
- Publication number
- JP2615418B2 JP2615418B2 JP6067803A JP6780394A JP2615418B2 JP 2615418 B2 JP2615418 B2 JP 2615418B2 JP 6067803 A JP6067803 A JP 6067803A JP 6780394 A JP6780394 A JP 6780394A JP 2615418 B2 JP2615418 B2 JP 2615418B2
- Authority
- JP
- Japan
- Prior art keywords
- titanium
- gold
- metal oxide
- catalyst
- based metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000010931 gold Substances 0.000 title claims description 136
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 title claims description 117
- 229910052737 gold Inorganic materials 0.000 title claims description 115
- 229910044991 metal oxide Inorganic materials 0.000 title claims description 97
- 150000004706 metal oxides Chemical class 0.000 title claims description 96
- 239000010936 titanium Substances 0.000 title claims description 94
- 229910052719 titanium Inorganic materials 0.000 title claims description 94
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 title claims description 93
- 239000002245 particle Substances 0.000 title claims description 80
- 239000003054 catalyst Substances 0.000 title claims description 63
- 238000007254 oxidation reaction Methods 0.000 title claims description 28
- 230000003647 oxidation Effects 0.000 title claims description 23
- 230000009467 reduction Effects 0.000 title claims description 8
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims description 37
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 35
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 34
- 239000001257 hydrogen Substances 0.000 claims description 16
- 229910052739 hydrogen Inorganic materials 0.000 claims description 16
- 238000007084 catalytic combustion reaction Methods 0.000 claims description 5
- 125000004435 hydrogen atom Chemical class [H]* 0.000 claims description 2
- 239000007864 aqueous solution Substances 0.000 description 40
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 34
- 238000000034 method Methods 0.000 description 34
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 30
- 150000002344 gold compounds Chemical class 0.000 description 26
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 24
- WDZVNNYQBQRJRX-UHFFFAOYSA-K gold(iii) hydroxide Chemical compound O[Au](O)O WDZVNNYQBQRJRX-UHFFFAOYSA-K 0.000 description 24
- 239000000243 solution Substances 0.000 description 24
- 239000007789 gas Substances 0.000 description 23
- 229910021505 gold(III) hydroxide Inorganic materials 0.000 description 23
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 14
- 238000006243 chemical reaction Methods 0.000 description 14
- 239000000843 powder Substances 0.000 description 13
- 239000000725 suspension Substances 0.000 description 13
- 229910010413 TiO 2 Inorganic materials 0.000 description 12
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 12
- 239000002253 acid Substances 0.000 description 10
- 239000002131 composite material Substances 0.000 description 10
- 239000007788 liquid Substances 0.000 description 10
- 238000006722 reduction reaction Methods 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 150000002431 hydrogen Chemical class 0.000 description 9
- 239000011882 ultra-fine particle Substances 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 8
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 8
- 230000010718 Oxidation Activity Effects 0.000 description 8
- 230000003197 catalytic effect Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 8
- 238000003756 stirring Methods 0.000 description 8
- 241000264877 Hippospongia communis Species 0.000 description 7
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 7
- 229910002367 SrTiO Inorganic materials 0.000 description 7
- 230000001603 reducing effect Effects 0.000 description 7
- 229910000029 sodium carbonate Inorganic materials 0.000 description 7
- 239000003638 chemical reducing agent Substances 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 229910052697 platinum Inorganic materials 0.000 description 6
- 239000002244 precipitate Substances 0.000 description 6
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 5
- 230000008021 deposition Effects 0.000 description 5
- 150000002500 ions Chemical class 0.000 description 5
- 230000001590 oxidative effect Effects 0.000 description 5
- 238000001556 precipitation Methods 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 4
- 230000002378 acidificating effect Effects 0.000 description 4
- 239000001569 carbon dioxide Substances 0.000 description 4
- 229910002092 carbon dioxide Inorganic materials 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 4
- 239000011734 sodium Substances 0.000 description 4
- 239000006228 supernatant Substances 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 235000011114 ammonium hydroxide Nutrition 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 238000005470 impregnation Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 3
- DLFVBJFMPXGRIB-UHFFFAOYSA-N Acetamide Chemical compound CC(N)=O DLFVBJFMPXGRIB-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910003771 Gold(I) chloride Inorganic materials 0.000 description 2
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000012670 alkaline solution Substances 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- BIVUUOPIAYRCAP-UHFFFAOYSA-N aminoazanium;chloride Chemical compound Cl.NN BIVUUOPIAYRCAP-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 229910052878 cordierite Inorganic materials 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
- 239000000446 fuel Substances 0.000 description 2
- FDWREHZXQUYJFJ-UHFFFAOYSA-M gold monochloride Chemical compound [Cl-].[Au+] FDWREHZXQUYJFJ-UHFFFAOYSA-M 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 2
- 230000003100 immobilizing effect Effects 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000001294 propane Substances 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 description 2
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- ICUOJQQLIWOITQ-UHFFFAOYSA-N N-ethylethanamine trihydrochloride Chemical compound CCNCC.Cl.Cl.Cl ICUOJQQLIWOITQ-UHFFFAOYSA-N 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- WEUCVIBPSSMHJG-UHFFFAOYSA-N calcium titanate Chemical compound [O-2].[O-2].[O-2].[Ca+2].[Ti+4] WEUCVIBPSSMHJG-UHFFFAOYSA-N 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 150000004683 dihydrates Chemical class 0.000 description 1
- ISDDBQLTUUCGCZ-UHFFFAOYSA-N dipotassium dicyanide Chemical compound [K+].[K+].N#[C-].N#[C-] ISDDBQLTUUCGCZ-UHFFFAOYSA-N 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 150000002343 gold Chemical class 0.000 description 1
- IZLAVFWQHMDDGK-UHFFFAOYSA-N gold(1+);cyanide Chemical compound [Au+].N#[C-] IZLAVFWQHMDDGK-UHFFFAOYSA-N 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 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 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 239000012702 metal oxide precursor Substances 0.000 description 1
- 239000006262 metallic foam Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 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
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- -1 titanium metal oxide Chemical class 0.000 description 1
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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Description
【０００１】本発明は、触媒燃焼用酸化触媒、一酸化炭
素および水素の酸化用触媒、窒素酸化物還元用触媒なら
びに電極用触媒に関する。The present invention relates to an oxidation catalyst for catalytic combustion, a catalyst for oxidizing carbon monoxide and hydrogen, a catalyst for reducing nitrogen oxides, and a catalyst for electrodes.
【０００２】[0002]
【従来の技術及びその問題点】粒径０．１μｍ程度以下
の金超微粒子は、通常の粗大粒子とは異なった特異な物
理的、化学的性質を示すことが知られている（「超微粒
子」アグネ出版センター刊、１９８６）。2. Description of the Related Art It is known that ultrafine gold particles having a particle size of about 0.1 μm or less exhibit unique physical and chemical properties different from ordinary coarse particles (“ultrafine particles”). Agne Publishing Center, 1986).
【０００３】しかしながら、超微粒子は、表面エネルギ
ーが大きく、非常に凝固しやすいために、取扱いが困難
である。特に金は、Ｐｔ、Ｐｄなどの他の貴金属に比べ
て融点が低く（金：１０６３℃、白金：１７６９℃、パ
ラジウム１５５０℃）、かつ金属同志の結合が強いため
に、超微粒子が凝集しやすく、超微粒子としての特徴を
充分に引き出すことが困難であった。However, ultrafine particles are difficult to handle because they have a large surface energy and are very easy to solidify. In particular, gold has a lower melting point than other noble metals such as Pt and Pd (gold: 1063 ° C., platinum: 1769 ° C., palladium 1550 ° C.), and has a strong bond between metals, so that ultrafine particles are easily aggregated. However, it was difficult to sufficiently bring out the characteristics as ultrafine particles.
【０００４】このため、金超微粒子を均一に分散した状
態で担体に担持乃至固定化する方法の開発が要望されて
おり、例えば、マンガン、鉄、コバルト、ニッケル、銅
などの水溶性化合物と金化合物とを含む混合水溶液を用
いて共沈法により、金属酸化物中に金化合物が分散した
複合材料を得る方法が報告されている（特開昭６０−２
３８１４８号公報）。しかしながら、このような方法で
は、チタンを主成分とする酸化物を担体とする複合材料
であって、触媒特性に優れたものは得られていない。ま
た、この方法では、チタンを主成分とする酸化物の成形
体や酸化チタンを担持した成形体に対しては、金超微粒
子を固定することができないので、使用形態が限定され
るという欠点があり、さらに金の使用量が多くなるとい
う欠点もある。[0004] For this reason, there has been a demand for the development of a method of carrying or immobilizing ultrafine gold particles on a carrier in a state of being uniformly dispersed. For example, a water-soluble compound such as manganese, iron, cobalt, nickel or copper and gold are required. A method of obtaining a composite material in which a gold compound is dispersed in a metal oxide by a coprecipitation method using a mixed aqueous solution containing a compound has been reported (Japanese Patent Application Laid-Open No. Sho 60-2).
38148). However, according to such a method, a composite material having an oxide containing titanium as a main component as a carrier and having excellent catalytic properties has not been obtained. In addition, this method has a disadvantage that the use form is limited because ultrafine gold particles cannot be fixed to a molded body of an oxide containing titanium as a main component or a molded body carrying titanium oxide. There is also a drawback that the amount of gold used increases.
【０００５】また、金を含有する水溶液に、担体を浸漬
し、尿素および／またはアセトアミドを用いて、担体上
に金超微粒子を析出させる方法もある（特願昭６０−１
９２７７５号）。しかしながら、この方法では、金の析
出の条件を精密に制御することが不可欠であり、また、
担持させるために数時間という長い時間を要するという
欠点がある。さらに、金の水溶液から金成分の一部を沈
殿析出させることができるだけなので、金の利用率が低
く、製造コストが高くなるという欠点もある。さらにま
た、得られる金の析出物が不均一で粗大なかたまりとな
り易く、金析出物の粒径制御が困難である。There is also a method in which a carrier is immersed in an aqueous solution containing gold, and ultrafine gold particles are deposited on the carrier using urea and / or acetamide (Japanese Patent Application No. 60-1970).
92775). However, in this method, it is essential to precisely control the conditions of gold deposition,
There is a drawback that it takes a long time of several hours to carry. Furthermore, since only a part of the gold component can be precipitated from an aqueous solution of gold, there is a disadvantage that the utilization rate of gold is low and the production cost is high. Furthermore, the resulting gold deposits tend to be non-uniform and coarse, and it is difficult to control the particle size of the gold deposits.
【０００６】従って、現在のところ、触媒などとして十
分満足すべき性能を備えた、担体上に金超微粒子を固定
した複合材料は、得られていない。[0006] Therefore, a composite material having ultra-fine gold particles fixed on a carrier, which has satisfactory performance as a catalyst or the like, has not been obtained at present.
【０００７】[0007]
【発明が解決しようとする課題】従って、本発明は、チ
タンを主成分とする金属酸化物からなる担体上に金微粒
子を均一且つ強固に固定化した複合材料であって、各種
用途における触媒として有用な複合材料を簡単な手法で
製造し、これを所定の反応において有効に利用する技術
を提供することを主な目的とする。SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a composite material in which fine gold particles are uniformly and firmly fixed on a carrier composed of a metal oxide containing titanium as a main component. A main object of the present invention is to provide a technique for producing a useful composite material by a simple method and effectively using the composite material in a predetermined reaction.
【０００８】[0008]
【問題点を解決するための手段】本発明者は、上記の如
き従来技術の問題点に鑑みて、チタンを主成分とする金
属酸化物からなる担体上に金超微粒子を均一かつ強固に
固定化した複合材料を簡単な方法で効率よく調製すべ
く、鋭意研究を重ねてきた。そして、金錯体イオンのア
ルカリ性水溶液中における沈殿生成・溶解反応、金属酸
化物などの表面への吸着挙動などに注目して、さらに研
究を進めた結果、水溶液のｐＨ値と金水溶性塩やその他
の添加物の添加方法を特定条件下に調整して行う場合に
は、チタンを主成分とする金属酸化物の表面に、金の水
酸化物又は金の超微粒子を均一に、しかも高効率で析出
させることができることを見出した。さらに、金の水酸
化物が析出した場合には、これを加熱することによっ
て、金超微粒子をチタンを主成分とする金属酸化物上に
均一かつ強固に固定担持することが可能となることを見
出した。さらにまた、得られた金超微粒子固定化チタン
系酸化物は、酸化触媒、還元触媒、可燃性ガスセンサ素
子、電極用触媒などの用途に極めて有用であることを見
出した。SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, the present inventor has fixed gold ultrafine particles uniformly and firmly on a carrier composed of a metal oxide containing titanium as a main component. In order to efficiently prepare a composite material by a simple method, intensive studies have been made. Focusing on the precipitation and dissolution reaction of gold complex ions in alkaline aqueous solution and the adsorption behavior of metal oxides on the surface, etc. In the case where the method of adding the additive is adjusted under specific conditions, the gold hydroxide or the ultrafine particles of gold are uniformly and highly efficiently applied to the surface of the metal oxide containing titanium as a main component. It has been found that it can be deposited. Furthermore, when gold hydroxide precipitates, it is possible to fix and carry the ultrafine gold particles uniformly and firmly on a metal oxide containing titanium as a main component by heating the gold hydroxide. I found it. Furthermore, they have found that the obtained titanium oxide fixed with ultrafine gold particles is extremely useful for applications such as oxidation catalysts, reduction catalysts, combustible gas sensor elements, and electrode catalysts.
【０００９】すなわち、本発明は、以下に示す金超微粒
子固定化チタン系酸化物からなる触媒燃焼用酸化触媒、
一酸化炭素および水素の酸化用触媒、窒素酸化物還元用
触媒ならびに電極用触媒を提供するものである； １．チタンを主成分とする金属酸化物に粒径２５０Å以
下の金微粒子を固定化したことを特徴とする金微粒子固
定化チタン系金属酸化物からなる触媒燃焼用酸化触媒。 ２．チタンを主成分とする金属酸化物に粒径２５０Å以
下の金微粒子を固定化したことを特徴とする金微粒子固
定化チタン系金属酸化物からなる一酸化炭素酸化用触
媒。 ３．チタンを主成分とする金属酸化物に粒径２５０Å以
下の金微粒子を固定化したことを特徴とする金微粒子固
定化チタン系金属酸化物からなる水素酸化用触媒。 ４．チタンを主成分とする金属酸化物に粒径２５０Å以
下の金微粒子を固定化したことを特徴とする金微粒子固
定化チタン系金属酸化物からなる窒素酸化物還元用触
媒。 ５．チタンを主成分とする金属酸化物に粒径２５０Å以
下の金微粒子を固定化したことを特徴とする金微粒子固
定化チタン系金属酸化物からなる電極用触媒。That is, the present invention provides an oxidation catalyst for catalytic combustion comprising a titanium-based oxide immobilized with ultrafine gold particles as described below:
It is intended to provide a catalyst for oxidizing carbon monoxide and hydrogen, a catalyst for reducing nitrogen oxides, and a catalyst for electrodes; An oxidation catalyst for catalytic combustion comprising a titanium-based metal oxide having gold particles fixed thereon, wherein gold particles having a particle size of 250 ° or less are fixed to a metal oxide containing titanium as a main component. 2. A catalyst for oxidizing carbon monoxide comprising a titanium-based metal oxide having gold particles fixed thereon, wherein gold particles having a particle size of 250 ° or less are fixed to a metal oxide containing titanium as a main component. 3. A hydrogen oxidation catalyst comprising a titanium-based metal oxide having gold particles fixed thereon, wherein gold particles having a particle size of 250 ° or less are fixed to a metal oxide containing titanium as a main component. 4. A nitrogen oxide reduction catalyst comprising a titanium-based metal oxide having gold particles fixed thereon, wherein gold particles having a particle size of 250 ° or less are fixed to a metal oxide containing titanium as a main component. 5. An electrode catalyst comprising a titanium-based metal oxide having gold particles fixed thereon, wherein gold particles having a particle size of 250 ° or less are fixed to a metal oxide containing titanium as a main component.
【００１０】[0010]
【００１１】[0011]
【００１２】[0012]
【００１３】本発明が対象とする金超微粒子固定化チタ
ン系金属酸化物は、以下に挙げる方法で得ることができ
る。The titanium-based metal oxide immobilized on ultrafine gold particles targeted by the present invention can be obtained by the following method.
【００１４】（Ｉ）第１方法：まず、担体としてのチタ
ンを主成分とする金属酸化物を含有する液のｐＨを７〜
１１、好ましくは７．５〜１０とし、攪拌下にこの水溶
液に金化合物の水溶液を滴下して、チタンを主成分とす
る金属酸化物上に金水酸化物を付着させる。次いで、こ
の金水酸化物を付着するチタン系金属酸化物を１００〜
８００℃に加熱することにより、チタン系酸化物表面に
金超微粒子を析出させて固定化する。(I) First method: First, the pH of a solution containing a metal oxide containing titanium as a main component as a carrier is adjusted to 7 to 10.
An aqueous solution of a gold compound is dropped into the aqueous solution with stirring, preferably to 7.5 to 10, to attach a gold hydroxide to a metal oxide containing titanium as a main component. Then, the titanium-based metal oxide to which the gold hydroxide is attached is 100 to 100%.
By heating to 800 ° C., ultrafine gold particles are precipitated and fixed on the surface of the titanium-based oxide.
【００１５】この方法では、チタンを主成分とする金属
酸化物としては、ＴｉＯ2 だけではなく、例えば、Ｆｅ
ＴｉＯ3 、ＣａＴｉＯ3 、ＳｒＴｉＯ3 などのチタン含
有複合酸化物を用いることができる。なお、本発明にお
ける「チタンを主成分とする酸化物」には、加熱によっ
てチタン酸化物乃至チタン含有金属酸化物を形成しうる
炭酸塩、水酸化物などのいわゆる「金属酸化物の前駆
体」も含むものとする。In this method, the metal oxide containing titanium as a main component is not limited to TiO 2 but may be, for example, Fe
Titanium-containing composite oxides such as TiO 3 , CaTiO 3 , and SrTiO 3 can be used. In the present invention, the “oxide mainly containing titanium” includes so-called “metal oxide precursors” such as carbonates and hydroxides that can form a titanium oxide or a titanium-containing metal oxide by heating. Shall be included.
【００１６】チタン酸化物乃至チタン含有金属酸化物
（本明細書においては、この両者を単にチタン系金属酸
化物ということがある）の形状は、特に限定はされず、
粉体状で用いる以外に、各種の形状に成形して用いるこ
ともできる。また、アルミナ、シリカ、マグネシア、コ
ージェライト等のセラミックスや各種の金属製の発泡
体、ハニカム、ペレットなどの支持体上にチタン系金属
酸化物を固定した状態で用いることもできる。The shape of the titanium oxide or the titanium-containing metal oxide (both may be simply referred to as a titanium-based metal oxide in the present specification) is not particularly limited.
In addition to using it in a powder form, it can be used after being formed into various shapes. In addition, a titanium-based metal oxide can be used in a state where the titanium-based metal oxide is fixed on a support such as ceramics such as alumina, silica, magnesia, and cordierite, and various metal foams, honeycombs, and pellets.
【００１７】チタン系金属酸化物の水中への添加量は、
特に限定はなく、例えば粉体状の金属酸化物を用いる場
合には、それを水中に均一に分散乃至縣濁できるような
量であればよく、通常１０〜２００ｇ／ｌ程度が適当で
ある。また、チタン系金属酸化物を成形体として用いる
場合には、成形体の形状に応じて、その表面に水溶液が
充分に接触できる状態であれば、金属酸化物担体の添加
量は、特に限定されない。The amount of titanium metal oxide added to water is as follows:
There is no particular limitation. For example, when a powdery metal oxide is used, the amount may be such that the metal oxide can be uniformly dispersed or suspended in water, and usually about 10 to 200 g / l is appropriate. In addition, when using a titanium-based metal oxide as a molded body, the amount of the metal oxide carrier to be added is not particularly limited as long as the aqueous solution can sufficiently contact the surface thereof according to the shape of the molded body. .
【００１８】水溶液の形態で使用する金化合物として
は、塩化金酸（ＨＡｕＣｌ4）、塩化金酸ナトリウム
（ＮａＡｕＣｌ4）、シアン化金（ＡｕＣＮ）、シアン
化金カリウム｛Ｋ〔Ａｕ（ＣＮ）2〕｝、三塩化ジエチ
ルアミン金酸〔（Ｃ2Ｈ5）2 ＮＨ・ＡｕＣｌ3 〕などの
水溶性金塩が例示される。滴下に用いる金化合物水溶液
の濃度は、特に限定されないが、通常０．１〜０．００
１ｍｏｌ／ｌ程度が適当である。As the gold compound used in the form of an aqueous solution, chloroauric acid (HAuCl 4 ), sodium chloroaurate (NaAuCl 4 ), gold cyanide (AuCN), potassium potassium cyanide ｛K [Au (CN) 2 ]}, water-soluble gold salts such as trichloride diethylamine auric acid [(C 2 H 5) 2 NH · AuCl 3 ] is exemplified. The concentration of the gold compound aqueous solution used for dropping is not particularly limited, but is usually 0.1 to 0.00.
About 1 mol / l is appropriate.
【００１９】金属酸化物を含む縣濁液乃至分散液を所定
のｐＨ範囲に調整するためには、通常、炭酸ナトリウ
ム、水酸化ナトリウム、炭酸カリウム、アンモニアなど
のアルカリ化合物を用いればよい。In order to adjust the suspension or dispersion containing the metal oxide to a predetermined pH range, generally, an alkali compound such as sodium carbonate, sodium hydroxide, potassium carbonate, ammonia or the like may be used.
【００２０】金化合物の水溶液は、急激な反応によって
金の水酸化物の大きな沈殿が生じないように、攪拌下に
上記の縣濁液乃至分散液に対し徐々に滴下することが必
要であり、通常滴下量に応じて滴下時間を３〜６０分程
度の範囲内とし、且つ水酸化物の大きな沈殿が生じない
ように滴下速度を適宜調節すればよい。The aqueous solution of the gold compound needs to be gradually added dropwise to the above suspension or dispersion under stirring so that a large precipitation of gold hydroxide does not occur due to a rapid reaction. Usually, the dropping time may be in the range of about 3 to 60 minutes depending on the dropping amount, and the dropping rate may be appropriately adjusted so that large precipitation of hydroxide does not occur.
【００２１】滴下時のチタン系金属酸化物含有液の液温
は、２０〜８０℃程度が適当である。The temperature of the titanium-containing metal oxide-containing liquid at the time of dropping is suitably about 20 to 80 ° C.
【００２２】金化合物の水溶液の滴下量は、チタン系金
属酸化物上に担持させる金超粒子の量によって決定され
る。担持量の上限は、使用するチタン系金属酸化物の種
類やその形状、比表面積などによって異なるが、通常
０．１〜１０重量％程度まで担持させることができる。The amount of the aqueous solution of the gold compound dropped is determined by the amount of the gold superparticles to be supported on the titanium-based metal oxide. The upper limit of the amount supported depends on the type, shape, specific surface area, etc. of the titanium-based metal oxide used, but can be generally supported up to about 0.1 to 10% by weight.
【００２３】第１方法では、金化合物水溶液を徐々に滴
下するので、滴下時に、金の水酸化物が液相で生成して
も、すぐに再溶解し、この再溶解した金化合物がチタン
系金属酸化物表面に吸着されて、チタン系金属酸化物を
核として、その表面に金が水酸化物として付着する。こ
のため、滴下した金化合物が水溶液中に沈殿析出するこ
とはない。In the first method, since the aqueous solution of the gold compound is gradually dropped, even if a gold hydroxide is formed in the liquid phase at the time of dropping, it is immediately redissolved, and the redissolved gold compound becomes a titanium-based solution. Adsorbed on the surface of the metal oxide, the titanium-based metal oxide as a nucleus, and gold adheres to the surface as a hydroxide. Therefore, the dropped gold compound does not precipitate in the aqueous solution.
【００２４】金化合物水溶液を滴下した分散乃至縣濁液
中では、通常、金は負の電荷を有する錯イオンとして存
在する。このためチタン系金属酸化物への金の付着効率
を上げるためには、分散乃至縣濁液のｐＨをチタン系金
属酸化物担体の等電位点よりも低い値、即ち酸性側とし
て、チタン系金属酸化物の表面が正の電荷を有するよう
に調整することが好ましい。また、等電位点よりもアル
カリ性側のｐＨとする場合にも、できるだけ等電位点に
近いｐＨ値とすることが適当であり、好ましくは、等電
位点のｐＨ値よりも０．５程度高いｐＨ値以下で用い
る。In a dispersion or suspension in which an aqueous solution of a gold compound is dropped, gold usually exists as a complex ion having a negative charge. Therefore, in order to increase the adhesion efficiency of gold to the titanium-based metal oxide, the pH of the dispersion or suspension is set to a value lower than the equipotential point of the titanium-based metal oxide carrier, that is, the acid side, It is preferable that the surface of the oxide be adjusted to have a positive charge. In addition, even when the pH is set to be more alkaline than the equipotential point, it is appropriate to set the pH value as close to the equipotential point as possible. Use below the value.
【００２５】金化合物は、通常ｐＨ７〜１１程度の状態
で水酸化物としてチタン系金属酸化物に付着しやすい
が、付着する際に、酸性イオンを放出して、混合反応液
のｐＨを下げる傾向にある。例えば、金化合物として、
ＨＡｕＣｌ4を用いる場合には、Ｃｌ- イオンを放出し
て液のｐＨが低下する。このため、均一な金超微粒子の
析出物を得るためには、適宜アルカリ水溶液を滴下し
て、混合反応液のｐＨの変動を抑制することが好まし
い。特に、ｐＨ７〜８程度の低ｐＨで反応を行う場合に
は、ｐＨが７以下とならないように金化合物水溶液とア
ルカリ水溶液とを同時に滴下することが好ましい。The gold compound usually easily adheres to the titanium-based metal oxide as a hydroxide at a pH of about 7 to 11, but when it adheres, it tends to release acidic ions to lower the pH of the mixed reaction solution. It is in. For example, as a gold compound,
When HAuCl 4 is used, Cl − ions are released to lower the pH of the solution. For this reason, in order to obtain a uniform precipitate of ultrafine gold particles, it is preferable to suppress the fluctuation of the pH of the mixed reaction solution by appropriately adding an aqueous alkaline solution. In particular, when the reaction is performed at a low pH of about 7 to 8, it is preferable to simultaneously drop the aqueous gold compound solution and the aqueous alkaline solution so that the pH does not become 7 or less.
【００２６】金の水酸化物が付着したチタン系金属酸化
物を１００〜８００℃に加熱することによって、付着し
た金の水酸化物が分解されて、チタン系金属酸化物上に
金が均一に超微粒子として析出し、強度に固定される。
加熱時間は通常１〜２４時間程度とすればよい。When the titanium-based metal oxide to which the gold hydroxide is attached is heated to 100 to 800 ° C., the attached gold hydroxide is decomposed, and the gold is uniformly deposited on the titanium-based metal oxide. Precipitates as ultrafine particles and is fixed in strength.
The heating time may usually be about 1 to 24 hours.
【００２７】（II）第２方法：金化合物を溶解してお
り、ｐＨ７〜１１（好ましくはｐＨ７．５〜１０）であ
って、チタン系金属酸化物を含有する液に、還元剤の水
溶液を攪拌下に滴下し、チタン系金属酸化物表面に金を
還元析出させて、金の超微粒子を固定化する。金化合
物、チタン系金属酸化物、ｐＨ調整用のアルカリ性化合
物などは、上記第１方法と同様のものが使用できる。チ
タン系金属酸化物の添加量も、上記第１方法と同様でよ
い。本第２方法では、液中の金化合物の濃度は、１×１
０-2〜１×１０-5ｍｏｌ／ｌ程度とすることが適当であ
る。チタン系金属酸化物含有水溶液の反応時の液温は、
０〜８０℃程度が適当である。(II) Second method: A gold compound is dissolved, pH 7 to 11 (preferably pH 7.5 to 10), and an aqueous solution of a reducing agent is added to a liquid containing a titanium-based metal oxide. The solution is added dropwise with stirring, and gold is reduced and precipitated on the surface of the titanium-based metal oxide to fix ultrafine gold particles. As the gold compound, the titanium-based metal oxide, the alkaline compound for pH adjustment, and the like, those similar to those in the first method can be used. The addition amount of the titanium-based metal oxide may be the same as in the first method. In the second method, the concentration of the gold compound in the solution is 1 × 1
It is appropriate to set it to about 0 -2 to 1 × 10 −5 mol / l. The liquid temperature during the reaction of the aqueous solution containing the titanium-based metal oxide is:
About 0 to 80 ° C. is appropriate.
【００２８】還元剤としては、ヒドラジン、ホルマリ
ン、クエン酸ナトリウムなどが使用でき、その溶液とし
ての濃度は、１×１０-1〜１×１０-3ｍｏｌ／ｌ程度で
ある。還元剤水溶液の添加量は、化学量論的に必要な量
の１．５〜１０倍程度とすることが適当である。還元剤
水溶液は、反応液中で急激な金の析出が生じないように
徐々に滴下することが必要であり、通常、３〜６０分程
度の時間をかけて滴下すればよい。As the reducing agent, hydrazine, formalin, sodium citrate and the like can be used, and the concentration of the solution is about 1 × 10 -1 to 1 × 10 -3 mol / l. The amount of the aqueous reducing agent added is suitably about 1.5 to 10 times the stoichiometrically required amount. The reducing agent aqueous solution needs to be gradually dropped so as not to cause rapid precipitation of gold in the reaction solution, and it is usually sufficient to drop the solution over a period of about 3 to 60 minutes.
【００２９】還元剤溶液の滴下によって、チタン系金属
酸化物表面に吸着された金化合物が金に還元されて、強
固に付着する。By the dropping of the reducing agent solution, the gold compound adsorbed on the surface of the titanium-based metal oxide is reduced to gold and adheres firmly.
【００３０】金属酸化物としてＣａＴｉＯ3 、ＳｒＴｉ
Ｏ3 などを用いる場合には、ｐＨ１１程度の高ｐＨ値で
も、金化合物は、高効率で金属酸化物に付着する。これ
に対し、酸化チタン（ＴｉＯ2 ）を用いる場合には、こ
のような高ｐＨ値では、金属酸化物表面が強く負に帯電
して、金化合物の付着効率が悪くなる場合が多い。この
ような場合には、反応液のｐＨを７〜８程度として、金
属酸化物を正に帯電させるか、或いは負に帯電する場合
であっても、負の電荷量をある程度少なくすることが好
ましい。反応液のｐＨを７〜８とする場合には、還元剤
の滴下と同時にアルカリ水溶液を滴下し、反応液のｐＨ
が低下しないように調整することによって、金の還元析
出速度をほぼ一定に維持することが好ましい。As the metal oxide, CaTiO 3 , SrTi
When O 3 or the like is used, even at a high pH value of about pH 11, the gold compound adheres to the metal oxide with high efficiency. On the other hand, when titanium oxide (TiO 2 ) is used, the metal oxide surface is strongly negatively charged at such a high pH value, and the adhesion efficiency of the gold compound is often deteriorated. In such a case, it is preferable to make the pH of the reaction solution about 7 to 8 to charge the metal oxide positively or to reduce the amount of negative charge to some extent even when the metal oxide is charged negatively. . When the pH of the reaction solution is 7 to 8, an alkaline aqueous solution is dropped simultaneously with the dropping of the reducing agent, and the pH of the reaction solution is lowered.
It is preferable to maintain the reduction deposition rate of gold substantially constant by adjusting so as not to decrease.
【００３１】なお、得られた金超微粒子固定化チタン系
金属酸化物はそのままでも常温で使用できるが、これを
高温で使用する場合には、高温での安定性確保のため
に、使用に先立って、一旦使用温度付近の温度に該金超
微粒子固定化チタン系金属酸化物を加熱しておくことが
好ましい。The obtained titanium-based metal oxide fixed with ultrafine gold particles can be used as it is at normal temperature. However, when it is used at a high temperature, it is necessary to use it at a high temperature in order to ensure stability at a high temperature. It is preferable that the titanium-based metal oxide having the ultrafine gold particles fixed thereon is once heated to a temperature near the use temperature.
【００３２】（III ）第３方法：金化合物を溶解し、ｐ
Ｈ１１以上（好ましくはｐＨ１１〜１２）であって、チ
タン系金属酸化物を含有する液に、二酸化炭素ガスを吹
き込むか、或いは攪拌下に酸性水溶液を徐々に滴下し
て、液のｐＨを７〜１１に低下させ、チタン系金属酸化
物の表面に金水酸化物を付着させる。次いで、このチタ
ン系金属酸化物を１００〜８００℃に加熱して、チタン
系金属酸化物表面に金超微粒子を析出させる。(III) Third method: dissolving a gold compound and adding p
H11 or more (preferably pH 11 to 12), a carbon dioxide gas is blown into a liquid containing a titanium-based metal oxide, or an acidic aqueous solution is gradually dropped while stirring to adjust the pH of the liquid to 7 to 11. The gold hydroxide is attached to the surface of the titanium-based metal oxide. Next, the titanium-based metal oxide is heated to 100 to 800 ° C. to precipitate ultrafine gold particles on the surface of the titanium-based metal oxide.
【００３３】金化合物、チタン系金属酸化物、アルカリ
性化合物の種類及び使用量などは、第１方法と同様でよ
い。チタン系金属酸化物を含有する液の液温は、２０〜
８０℃程度とすればよい。The types and amounts of the gold compound, titanium-based metal oxide and alkaline compound may be the same as those in the first method. The temperature of the liquid containing the titanium-based metal oxide is 20 to
The temperature may be about 80 ° C.
【００３４】この方法では、金化合物は、水酸基が過剰
に結合した錯イオンとして、チタン系金属酸化物を含有
する液中に溶解した状態で存在することが必要である。
従って、使用する金化合物に応じて、ｐＨ１１以上であ
って金化合物が水酸基含有錯イオンとして溶解する状態
となるように、チタン系金属酸化物含有液のｐＨを調整
する。In this method, it is necessary that the gold compound be present as a complex ion in which a hydroxyl group is excessively bonded, in a state of being dissolved in a liquid containing a titanium-based metal oxide.
Therefore, the pH of the titanium-based metal oxide-containing liquid is adjusted so that the pH is 11 or more and the gold compound is dissolved as a hydroxyl-containing complex ion depending on the gold compound used.
【００３５】この様な状態に調整した液中に二酸化炭素
ガスを吹き込むか、または酸性水溶液を徐々に滴下し
て、溶液のｐＨを徐々に低下させて、ｐＨ７〜１１とす
ることにより、チタン系金属酸化物を核として、金の水
酸化物が析出し、チタン系金属酸化物表面に付着する。A carbon dioxide gas is blown into the liquid adjusted to such a state, or an acidic aqueous solution is gradually dropped to gradually lower the pH of the solution to pH 7 to 11. Gold hydroxide precipitates with the metal oxide as a nucleus and adheres to the surface of the titanium-based metal oxide.
【００３６】二酸化炭素ガスの吹き込み速度は、特に限
定されず、反応液が均一にバブリングされる状態であれ
ばよい。The blowing speed of the carbon dioxide gas is not particularly limited as long as the reaction solution is uniformly bubbled.
【００３７】酸性水溶液としては、硝酸、塩酸、硫酸、
酢酸などの水溶液が使用でき、これらの酸水溶液は、１
×１０-1〜１×１０-3ｍｏｌ／ｌ程度の濃度で用いれば
よい。滴下量は、チタン系金属酸化物を含有する液のｐ
Ｈが７未満にならない範囲であればよい。滴下速度は、
金の水酸化物の大きな沈殿が生じないように、滴下時間
３〜６０分間程度の範囲で滴下量に応じて適宜決定すれ
ばよい。As the acidic aqueous solution, nitric acid, hydrochloric acid, sulfuric acid,
An aqueous solution such as acetic acid can be used.
It may be used at a concentration of about × 10 −1 to 1 × 10 −3 mol / l. The amount of drop is p of the solution containing the titanium-based metal oxide.
It suffices that H is within a range not smaller than 7. The dripping speed is
The dropping time may be appropriately determined in the range of about 3 to 60 minutes in accordance with the dropping amount so that a large precipitation of gold hydroxide does not occur.
【００３８】次いで、金の水酸化物が付着したチタン系
金属酸化物を１００〜８００℃に加熱することによっ
て、付着した金の水酸化物が分解され、チタン系金属酸
化物上に均一に金超微粒子が析出し、強固に固定化され
る。加熱時間は、通常１〜２４時間程度とすればよい。Next, by heating the titanium-based metal oxide to which the gold hydroxide is attached to 100 to 800 ° C., the attached gold hydroxide is decomposed, and the gold is uniformly deposited on the titanium-based metal oxide. Ultrafine particles precipitate and are firmly fixed. The heating time may be generally about 1 to 24 hours.
【００３９】なお、上記の各方法において、金化合物が
チタン系金属酸化物上に充分に付着するように、滴下ま
たは吹き込み終了後に３０分〜２時間程度の間チタン系
金属酸化物を含有する液の攪拌を行うことが好ましい。In each of the above methods, a solution containing the titanium-based metal oxide for about 30 minutes to 2 hours after the completion of the dropping or blowing so that the gold compound sufficiently adheres to the titanium-based metal oxide. Is preferably performed.
【００４０】上記の各方法によれば、粒径５００オング
ストローム程度以下で均一な粒径の金超微粒子をチタン
系金属酸化物上に固定化することができ、特に従来法で
は得られなかった２５０オングストローム程度以下の微
細な金超微粒子をチタン系金属酸化物に均一かつ強固に
担持させることが可能である。金超微粒子は、上記の第
１〜第３のいずれの方法においても、チタン系金属酸化
物に対し、０．１〜１０重量％程度まで担持させること
ができる。According to each of the above methods, ultrafine gold particles having a uniform particle diameter of about 500 angstroms or less can be immobilized on the titanium-based metal oxide. Ultrafine gold particles of about Å or less can be uniformly and firmly supported on the titanium-based metal oxide. In any of the above first to third methods, the ultrafine gold particles can be supported up to about 0.1 to 10% by weight with respect to the titanium-based metal oxide.
【００４１】上記の各方法では、チタン系金属酸化物を
粉体の状態で用いる以外にも、予め成形した状態で用い
たり、各種の支持体に固定した状態で用いることもでき
る。例えば、白金線などを埋め込んだ焼結体、電気リー
ドを接続した電極としてのチタン系金属酸化物の焼結体
などに直接金超微粒子を固定化することができる。In each of the above methods, in addition to using the titanium-based metal oxide in a powder state, the titanium-based metal oxide can be used in a previously molded state or in a state fixed to various supports. For example, ultrafine gold particles can be directly fixed to a sintered body in which a platinum wire or the like is embedded, or a titanium-based metal oxide sintered body as an electrode to which an electric lead is connected.
【００４２】上記の方法により得られる金超微粒子固定
化チタン系金属酸化物は、微細な金超微粒子がチタン系
金属酸化物上に均一に担持されたものであり、各種の用
途に使用できる。The titanium-based metal oxide immobilized with ultrafine gold particles obtained by the above method is obtained by uniformly supporting ultrafine gold particles on a titanium-based metal oxide, and can be used for various purposes.
【００４３】例えば、上記の各方法で得られた金超微粒
子固定化チタン系金属酸化物は、３００℃以下の比較的
低温で水素、一酸化炭素、メタノール、プロパンなどの
燃料を広い濃度範囲で燃焼できるので、触媒燃焼方式の
各種暖房器や厨房用加熱器用の触媒体として有用であ
る。また、石油ストーブ、石油ファンヒータ、ガスファ
ンヒータ用排ガス浄化触媒体として、或いは空調機器用
空気浄化触媒フィルタとして利用できる。その他にも、
塗料工業などにおける溶剤酸化処理用触媒体、工場排ガ
ス浄化用触媒体などとしても有用である。For example, the titanium-based metal oxide immobilized with ultrafine gold particles obtained by each of the above-mentioned methods can be used at a relatively low temperature of 300 ° C. or lower at a relatively low temperature to prepare a fuel such as hydrogen, carbon monoxide, methanol or propane in a wide concentration range. Since it can be burned, it is useful as a catalyst body for various catalytic combustion type heaters and kitchen heaters. Further, it can be used as an exhaust gas purifying catalyst for an oil stove, an oil fan heater, a gas fan heater, or as an air purifying catalyst filter for an air conditioner. In addition,
It is also useful as a catalyst for solvent oxidation treatment in the paint industry and a catalyst for purification of factory exhaust gas.
【００４４】また、上記の金超微粒子固定化チタン系金
属酸化物は、ＮＯ、ＮＯ2 などの窒素酸化物を水素、一
酸化炭素などを用いて還元するための触媒としても有用
である。The titanium-based metal oxide immobilized with ultrafine gold particles is also useful as a catalyst for reducing nitrogen oxides such as NO and NO 2 using hydrogen, carbon monoxide and the like.
【００４５】さらに、上記の金超微粒子固定化チタン系
金属酸化物は、水素、一酸化炭素、メタノール、炭化水
素などの可燃性ガスセンサー素子としても有用である。Further, the above-mentioned titanium-based metal oxide immobilized with ultrafine gold particles is also useful as a flammable gas sensor element for hydrogen, carbon monoxide, methanol, hydrocarbons and the like.
【００４６】さらにまた、上記の金超微粒子固定化チタ
ン系金属酸化物は、水素、一酸化炭素、メタノール、炭
化水素などを対象とした燃料電池やこれらのガスの電気
化学的反応用の電極用触媒として有用である。Further, the above-mentioned titanium-based metal oxide immobilized with ultrafine gold particles is used as a fuel cell for hydrogen, carbon monoxide, methanol, hydrocarbons and the like and an electrode for an electrochemical reaction of these gases. Useful as a catalyst.
【００４７】[0047]
【発明の効果】本発明の金微粒子固定化チタン系金属酸
化物を得るための方法では、各種の形態のチタン系金属
酸化物に対して、短時間で金超微粒子を固定・担持させ
ることができ、しかも金の利用効率が高いので、金化合
物の使用量を節減できる。According to the method for obtaining a titanium-based metal oxide having gold particles fixed thereon according to the present invention, ultra-fine gold particles can be fixed and supported on titanium-based metal oxides of various forms in a short time. In addition, since the use efficiency of gold is high, the amount of gold compound used can be reduced.
【００４８】また、予め成形した焼結体や各種の支持体
に固定したチタン系金属酸化物に直接金超微粒子を固定
することができるので、従来のプロセスで作製したガス
センサ素子や電極などに直接金超微粒子を固定化して、
これらの材料の性能を容易に向上させることができる。Further, since the ultrafine gold particles can be directly fixed to a pre-formed sintered body or a titanium-based metal oxide fixed to various supports, it can be directly applied to a gas sensor element or an electrode manufactured by a conventional process. Immobilize gold ultrafine particles,
The performance of these materials can be easily improved.
【００４９】より具体的には、本発明による金微粒子固
定化チタン系金属酸化物は、酸化触媒、還元触媒、可燃
性ガスセンサ、電極用触媒などとして極めて有用であ
る。More specifically, the titanium-based metal oxide immobilized with fine gold particles according to the present invention is extremely useful as an oxidation catalyst, a reduction catalyst, a flammable gas sensor, a catalyst for electrodes, and the like.
【００５０】[0050]
実施例１ 酸化チタン（ＴｉＯ2 ）粉末５．０ｇを５００ｍｌの水
に懸濁させた。この懸濁液を攪拌し、その中へ塩化金酸
（ＨＡｕＣｌ4 ）の水溶液および炭酸ナトリウム（Ｎａ
ＣＯ3 ）の水溶液を１０分間かけて同時に滴下した。こ
の時の塩化金酸水溶液の濃度は７．５×１０-3Ｍであ
り、滴下量は１００ｍｌであった。また、炭酸ナトリウ
ム水溶液の濃度は０．１Ｍであり、懸濁液のｐＨが７〜
８となるように滴下した。Example 1 5.0 g of titanium oxide (TiO 2 ) powder was suspended in 500 ml of water. The suspension is stirred and an aqueous solution of chloroauric acid (HAuCl 4 ) and sodium carbonate (Na
An aqueous solution of CO 3 ) was simultaneously added dropwise over 10 minutes. At this time, the concentration of the aqueous solution of chloroauric acid was 7.5 × 10 −3 M, and the dropping amount was 100 ml. The concentration of the aqueous sodium carbonate solution is 0.1 M, and the pH of the suspension is 7 to
8 was added dropwise.
【００５１】滴下終了後、懸濁液の攪拌を１時間継続し
て、酸化チタン表面上に水酸化金（III ）（Ａｕ（ＯＨ
3 ））を析出させた。無色透明の上澄液に水酸化ナトリ
ウムを加えてｐＨを１２にしてホルマリンを加えたとこ
ろ、金コロイドの析出により無色からわずかに淡い紫色
への変化が生じたが、分析の結果、溶液中の金の大部分
が酸化チタン上に析出したことが、わかった。After completion of the dropwise addition, stirring of the suspension was continued for 1 hour, and gold (III) hydroxide (Au (OH)
3 )) was precipitated. When sodium hydroxide was added to the colorless and transparent supernatant to adjust the pH to 12, and formalin was added, a change from colorless to slightly pale purple occurred due to the deposition of colloidal gold. It was found that most of the gold was deposited on the titanium oxide.
【００５２】次いで、水酸化金が析出した酸化チタンを
水洗し、乾燥し、さらに空気中４００℃で３時間焼成し
て水酸化金を熱分解することにより、酸化チタン表面に
金を担持した触媒Ａｕ（３ｗｔ％）／ＴｉＯ2 を得た。
触媒表面に担持された金は、金属状態でかつ粒子径が良
く揃い平均３５オングストローム以下であることを高分
解能透過型電子顕微鏡で確認した。Next, the titanium oxide on which the gold hydroxide was precipitated was washed with water, dried, and further calcined at 400 ° C. for 3 hours in air to thermally decompose the gold hydroxide, whereby a catalyst having gold supported on the titanium oxide surface was obtained. Au (3 wt%) / TiO 2 was obtained.
It was confirmed with a high-resolution transmission electron microscope that the gold supported on the catalyst surface was in a metallic state and had a uniform particle diameter and an average of 35 angstroms or less.
【００５３】次いで、上記触媒を４０〜７０メッシュに
ふるい分けしたものを０．２ｇ用いて、一酸化炭素（Ｃ
Ｏ）１容量％を含む空気混合ガスを６７ｍｌ／分で流通
させて、一酸化炭素に対する酸化活性を調べた。Next, 0.2 g of the above catalyst sieved to 40 to 70 mesh was used, and carbon monoxide (C
O) An air mixed gas containing 1% by volume was passed at a flow rate of 67 ml / min, and the oxidation activity on carbon monoxide was examined.
【００５４】その結果、−３５℃で５０％の酸化反応率
を示し、この触媒Ａｕ／ＴｉＯ2 が０℃以下の低温でも
高い一酸化炭素酸化活性を示すことが明らかとなった。As a result, it was found that the oxidation reaction rate was 50% at -35 ° C., and that this catalyst Au / TiO 2 exhibited high carbon monoxide oxidizing activity even at a low temperature of 0 ° C. or less.
【００５５】また、ＣＯを水素に代えて上記と同様の条
件で実験を行ったところ、４１℃で５０％の酸化反応率
を示し、触媒Ａｕ／ＴｉＯ2 は室温付近でも高い水素酸
化活性を示すことが明らかとなった。Further, an experiment was conducted under the same conditions as described above except that CO was replaced with hydrogen. As a result, the catalyst exhibited an oxidation reaction rate of 50% at 41 ° C., and the catalyst Au / TiO 2 exhibited a high hydrogen oxidation activity even at around room temperature. It became clear.
【００５６】実施例２ ４０〜７０メッシュにふるい分けたチタン酸ストロンチ
ウム（ＳｒＴｉＯ3 ）粉末５．０ｇを２５０ｍｌの水に
懸濁させた。Example 2 5.0 g of strontium titanate (SrTiO 3 ) powder sieved to 40 to 70 mesh was suspended in 250 ml of water.
【００５７】この懸濁液を攪拌しながら、その中へ塩化
金酸（ＨＡｕＣｌ4 ）水溶液および炭酸ナトリウム（Ｎ
ａ2 ＣＯ3 ）水溶液を３０分間かけて同時に滴下した。
この際の塩化金酸水溶液の濃度は２．５×１０-3Ｍであ
り、滴下量は１００ｍｌであった。また、炭酸ナトリウ
ム水溶液の濃度は０．１Ｍであり、懸濁液のｐＨが８〜
９に維持されるように滴下した。滴下終了後、懸濁液の
攪拌をさらに１時間継続し、ＳｒＴｉＯ3 表面に水酸化
金（III ）（Ａｕ（ＯＨ）3 ）を析出させた。無色透明
の上澄液に水酸化カリウムを加えてｐＨを１２にし、さ
らにホルマリンを加えたが、金の析出による色の変化は
僅かであり、溶液中の金の大部分がチタン酸ストロンチ
ウム上に析出したことがわかった。While stirring this suspension, an aqueous solution of chloroauric acid (HAuCl 4 ) and sodium carbonate (N
a 2 CO 3 ) aqueous solution was dropped simultaneously over 30 minutes.
At this time, the concentration of the aqueous solution of chloroauric acid was 2.5 × 10 −3 M, and the dropping amount was 100 ml. The concentration of the aqueous sodium carbonate solution is 0.1 M, and the pH of the suspension is 8 to
The solution was dropped so as to be maintained at 9. After completion of the dropwise addition, stirring of the suspension was continued for another hour to deposit gold (III) hydroxide (Au (OH) 3 ) on the surface of SrTiO 3 . Potassium hydroxide was added to the colorless and transparent supernatant to adjust the pH to 12, and formalin was further added, but the color change due to the deposition of gold was slight, and most of the gold in the solution was deposited on strontium titanate. It turned out that it precipitated.
【００５８】次いで、水酸化金が析出したＳｒＴｉＯ3
を水洗した後、乾燥し、さらに空気中４００℃で３時間
焼成し、水酸化金を熱分解することにより、ＳｒＴｉＯ
3 表面に金を担持した触媒Ａｕ（１ｗｔ％）／ＳｒＴｉ
Ｏ3 を得た。Next, SrTiO 3 on which gold hydroxide was deposited
Is washed with water, dried, and further calcined in air at 400 ° C. for 3 hours to thermally decompose the gold hydroxide to obtain SrTiO.
3 Au (1 wt%) catalyst supporting gold on the surface / SrTi
O 3 was obtained.
【００５９】触媒表面に担持された金は、金属状態でか
つ粒子径が１００オングストローム以下であることをＸ
線光電子分光法およびＸ線回折法で確認した。The gold supported on the catalyst surface is in a metallic state and has a particle diameter of 100 Å or less.
It was confirmed by X-ray photoelectron spectroscopy and X-ray diffraction.
【００６０】次いで、上記触媒を０．２ｇ用い、一酸化
炭素（ＣＯ）１容量％を含む空気混合ガスを６７ｍｌ／
分で流通させて、一酸化炭素の酸化活性を調べた。その
結果Ａｕ（１ｗｔ％）／ＳｒＴｉＯ3 は、室温付近で高
い一酸化炭素酸化活性を示すことが明らかとなった。Next, using 0.2 g of the above catalyst, 67 ml / air of an air mixed gas containing 1% by volume of carbon monoxide (CO) was used.
Per minute to examine the oxidation activity of carbon monoxide. As a result, it became clear that Au (1 wt%) / SrTiO 3 shows high carbon monoxide oxidation activity near room temperature.
【００６１】実施例３ 塩化金酸（ＨＡｕＣｌ4 ・４Ｈ2 Ｏ）０．２１ｇを溶か
したｐＨ７のアンモニア水溶液１００ｍｌ中に酸化チタ
ン（ＴｉＯ2 ）粉末２．０ｇを懸濁させた。この懸濁液
を室温で激しく攪拌しながら、滴下ロートに入った塩酸
ヒドラジンの３．７重量％水溶液３．５ｍｌと１０重量
％アンモニア水を同時に少量ずつ３０〜６０分間かけて
加えた。アンモニア水は、水溶液の最終ｐＨが８になる
まで添加した。塩酸ヒドラジン水溶液を加える前の反応
初期には、塩化金酸の存在により、水溶液は黄色透明を
呈していたが、還元反応終了後には、上澄液が無色透明
となり、液相中での金コロイド粒子の存在を示す赤色或
いは青色透明にはならなかった。これにより、酸化チタ
ン（ＴｉＯ2 ）表面上にのみ金が還元析出したことが確
認された。Example 3 2.0 g of titanium oxide (TiO 2 ) powder was suspended in 100 ml of an aqueous ammonia solution of pH 7 in which 0.21 g of chloroauric acid (HAuCl 4 .4H 2 O) was dissolved. While the suspension was vigorously stirred at room temperature, 3.5 ml of a 3.7 wt% aqueous solution of hydrazine hydrochloride and 10 wt% aqueous ammonia in a dropping funnel were simultaneously added in small portions over a period of 30 to 60 minutes. Aqueous ammonia was added until the final pH of the aqueous solution was 8. At the beginning of the reaction before adding the aqueous solution of hydrazine hydrochloride, the aqueous solution was yellow and transparent due to the presence of chloroauric acid, but after the reduction reaction, the supernatant became colorless and transparent, and the gold colloid in the liquid phase It did not become red or blue transparent indicating the presence of particles. This confirmed that gold was reduced and deposited only on the titanium oxide (TiO 2 ) surface.
【００６２】還元反応終了後の懸濁液をろ過し、洗浄
し、固形分を一昼夜かけて真空乾燥した後、空気中３０
０℃で５時間焼成して、金を５重量％固定・担持した酸
化チタン（ＴｉＯ2 ）を得た。After the reduction reaction is completed, the suspension is filtered, washed, and the solid content is dried in a vacuum for 24 hours.
Baking was performed at 0 ° C. for 5 hours to obtain titanium oxide (TiO 2 ) having 5% by weight of gold fixed and supported.
【００６３】この金を固定化した酸化チタン０．２ｇを
用い、メタノールを１容量％含む空気混合ガスを６７ｍ
ｌ／分で流通させて、メタノールの酸化活性を調べた。
その結果、１５０℃でメタノールの７０％を二酸化炭素
まで酸化できた。Using 0.2 g of the titanium oxide having gold immobilized thereon, 67 m of an air mixed gas containing 1% by volume of methanol was used.
The mixture was circulated at 1 / min to examine the oxidation activity of methanol.
As a result, 70% of methanol could be oxidized to carbon dioxide at 150 ° C.
【００６４】実施例４ 酸化チタン（ＴｉＯ2 ）粉末を湿式ミルで微粉砕したも
のにポリビニルアルコールを少量加え、ペースト状にし
た。これを５cm×５cm×２cmのコージライト製ハニカム
に塗布し、空気中４００℃で３時間焼成した。得られた
ハニカムをｐＨ８．５の炭酸ナトリウム水溶液２００ｍ
ｌに浸漬し、水溶液を循環ポンブで循環攪拌しながら、
塩化金酸ナトリウム２水和物〔Ｎａ（ＡｕＣｌ4 ）・２
Ｈ2 Ｏ〕０．３０ｇを溶かした水溶液５０ｍｌとｐＨ９
の炭酸ナトリウム水溶液５０ｍｌとをそれぞれ３０分間
かけて徐々に滴下した。Example 4 A small amount of polyvinyl alcohol was added to finely pulverized titanium oxide (TiO 2 ) powder in a wet mill to form a paste. This was applied to a 5 cm × 5 cm × 2 cm honeycomb made of cordierite and fired in air at 400 ° C. for 3 hours. The obtained honeycomb was treated with a sodium carbonate aqueous solution (pH 8.5: 200 m).
l while circulating and stirring the aqueous solution with a circulation pump.
Sodium chloroaurate dihydrate [Na (AuCl 4 ) .2
[H 2 O] 50 ml of an aqueous solution in which 0.30 g was dissolved and pH 9
And 50 ml of an aqueous solution of sodium carbonate was gradually added dropwise over 30 minutes.
【００６５】この場合にも、実施例１の場合と同様に、
還元反応終了後の上澄液は、無色透明であり、これに水
酸化カリウムを加えてｐＨ１２にし、ホルマリンを過剰
に加えても、金の析出による色の変化はごく僅かしか起
こらず、ハニカムに担持されている酸化チタン表面上に
のみ金が水酸化物として析出したことが確認された。次
いで、金を沈殿析出したハニカムを水溶液から取り出
し、洗浄後１２０℃で１２時間乾燥し、空気中５００℃
で３時間焼成して金超微粒子固定化酸化チタン担持ハニ
カム触媒を得た。触媒表面に担持された金は、金属状態
でかつ粒子径が約７０オングストロームであることがＸ
線回折法によって確認された。In this case, as in the case of the first embodiment,
The supernatant liquid after completion of the reduction reaction is colorless and transparent. Even if potassium hydroxide is added thereto to adjust the pH to 12, and formalin is excessively added, the color change due to the deposition of gold occurs very little, and the honeycomb is obtained. It was confirmed that gold was precipitated as a hydroxide only on the surface of the supported titanium oxide. Next, the honeycomb on which the gold was precipitated was taken out of the aqueous solution, washed, dried at 120 ° C. for 12 hours, and placed in air at 500 ° C.
For 3 hours to obtain a honeycomb catalyst supporting titanium oxide fixed with ultrafine gold particles. The gold supported on the catalyst surface is in a metal state and has a particle diameter of about 70 Å.
Confirmed by line diffraction.
【００６６】次いで、上記触媒にＣＯ１容量％と水分１
容量％とを含む空気混合ガスを１０リットル／分で流通
させて、一酸化炭素に対する酸化活性を調べた。その結
果、３５℃で８０％の酸化反応率を示し、金超微粒子固
定化酸化チタン担持ハニカム触媒は、室温で高い一酸化
炭素酸化活性を示すことが明らかとなった。Next, 1% by volume of CO and 1% of water were added to the above catalyst.
An air mixed gas containing 10% by volume was flowed at a rate of 10 liters / minute, and the oxidation activity on carbon monoxide was examined. As a result, an oxidation reaction rate of 80% was obtained at 35 ° C., and it was revealed that the titanium oxide-carrying honeycomb catalyst immobilized with ultrafine gold particles exhibited high carbon monoxide oxidation activity at room temperature.
【００６７】また、上記触媒にＣＯ１０００ｐｐｍおよ
び一酸化窒素（ＮＯ）１０００ｐｐｍを含むヘリウムガ
スを１０ｌ／分で流通させて、ＮＯに対する還元活性を
調べた。その結果、２５０℃ではＮＯの２５％がＮ2
に、３００℃ではＮＯの７０％がＮ2 に還元され、本発
明による金超微粒子固定化酸化チタン担持ハニカム触媒
は、２５０℃以上の温度範囲で高い一酸化窒素還元活性
を示すことが明らかとなった。A helium gas containing 1000 ppm of CO and 1000 ppm of nitrogen monoxide (NO) was passed through the catalyst at a rate of 10 l / min, and the reducing activity for NO was examined. As a result, 25% of 250 ° C. In NO N 2
In addition, at 300 ° C., 70% of NO is reduced to N 2 , and it is apparent that the titanium oxide-carrying titanium oxide-immobilized titanium oxide catalyst according to the present invention exhibits high nitric oxide reducing activity in a temperature range of 250 ° C. or higher. became.
【００６８】実施例５ チタン酸カルシウム（ＣａＴｉＯ3 ）顆粒５．０ｇを塩
化金酸（ＨＡｕＣｌ4）１．２５×１０-4ｍｏｌと水酸
化カリウム（ＫＯＨ）１．０×１０-2ｍｏｌとを含むｐ
Ｈ１１．５のアルカリ性水溶液５００ｍｌに懸濁させ
た。この懸濁液中に０．１Ｍの硝酸を２ｍｌ／分の速度
で滴下して、溶液のｐＨを８まで下げることにより、Ｃ
ａＴｉＯ3 表面に水酸化金（III ）〔Ａｕ（ＯＨ）3 〕
を析出させた。これを水洗し、乾燥し、さらに空気中４
００℃で３時間焼成し、水酸化金を熱分解させて、Ｃａ
ＴｉＯ3 表面に金を担持した触媒Ａｕ（０．５ｗｔ％）
／ＣａＴｉＯ3 を得た。EXAMPLE 5 5.0 g of calcium titanate (CaTiO 3 ) granules were mixed with 1.25 × 10 −4 mol of chloroauric acid (HAuCl 4 ) and 1.0 × 10 −2 mol of potassium hydroxide (KOH). Including p
H11.5 was suspended in 500 ml of an alkaline aqueous solution. 0.1 M nitric acid was dropped into the suspension at a rate of 2 ml / min to lower the pH of the solution to 8, thereby obtaining C
ATiO 3 surface gold hydroxide (III) [Au (OH) 3]
Was precipitated. This is washed with water, dried, and
Baking at 00 ° C. for 3 hours to thermally decompose the gold hydroxide,
Au (0.5 wt%) catalyst supporting gold on TiO 3 surface
/ CaTiO 3 was obtained.
【００６９】上記の触媒０．２ｇを用い、一酸化炭素
（ＣＯ）を１容量％含む空気混合ガスを６７ｍｌ／分で
流通させて、一酸化炭素の酸化活性を調べた。その結果
９０℃で８５％の酸化反応率を示した。このことから、
この触媒Ａｕ／ＣａＴｉＯ3 は、１００℃以下の温度で
高い一酸化炭素酸化活性を示すことが明らかとなった。Using 0.2 g of the above catalyst, an air mixed gas containing 1% by volume of carbon monoxide (CO) was passed at 67 ml / min, and the oxidation activity of carbon monoxide was examined. As a result, it showed an oxidation reaction rate of 85% at 90 ° C. From this,
It was found that this catalyst Au / CaTiO 3 shows high carbon monoxide oxidizing activity at a temperature of 100 ° C. or less.
【００７０】実施例６ 実施例２で作製したＡｕ（１ｗｔ％）／ＳｒＴｉＯ3 を
膜状の焼結体とし、電気抵抗が測定できるように２本の
電極を接続した。則ち、１０ｍｍ×１０ｍｍのアルミナ
基板（厚さ０．５ｍｍ）の表面に２本の電極用金線（直
径０．０５ｍｍ）を間隔１．０ｍｍとなるように並べ、
Ａｕ（１ｗｔ％）／ＳｒＴｉＯ3 粉末５００ｍｇに約１
ｍｌの水を加え、乳鉢で充分微粉砕して作ったペースト
を塗布した。これを１２０℃で１２時間乾燥後、空気中
４００℃で１時間焼成することにより、電極付き膜状焼
結体が得られ、これを可燃性ガスセンサ素子とした。Example 6 Au (1 wt%) / SrTiO 3 produced in Example 2 was used as a film-shaped sintered body, and two electrodes were connected so that electric resistance could be measured. That is, two gold wires for electrodes (diameter 0.05 mm) are arranged on the surface of a 10 mm × 10 mm alumina substrate (thickness 0.5 mm) so as to have an interval of 1.0 mm,
Au (1wt%) / SrTiO 3 powder 500mg
To the mixture was added water, and the paste was pulverized sufficiently in a mortar and applied. This was dried at 120 ° C. for 12 hours and then fired in air at 400 ° C. for 1 hour to obtain a film-shaped sintered body with electrodes, which was used as a combustible gas sensor element.
【００７１】可燃性ガスの検知感度は、ガスセンサ素子
の清浄空気中での電気抵抗値（Ｒａｉｒ）と被検ガスを
含む空気中での電気抵抗値（Ｒｇａｓ）との比で表わす
ものとする。ガスセンサ素子の温度を３００℃とした場
合、空気中に１００ｐｐｍ含まれる一酸化炭素、水素お
よびプロパンに対するＲａｉｒ／Ｒｇａｓは、それぞれ
８．５、２．２および１．５であり、一酸化炭素に対し
て特に優れた応答感度を示すことが明らかとなった。The detection sensitivity of the combustible gas is represented by the ratio of the electric resistance value (Rair) of the gas sensor element in clean air to the electric resistance value (Rgas) in the air containing the test gas. When the temperature of the gas sensor element is 300 ° C., Rair / Rgas with respect to carbon monoxide, hydrogen, and propane contained in air at 100 ppm are 8.5, 2.2, and 1.5, respectively. It was found that they exhibited particularly excellent response sensitivity.
【００７２】実施例７ 実施例１で作製したＡｕ（３ｗｔ％）／ＴｉＯ2 粉末を
乳鉢で微粉砕したものと白金１ｗｔ％を担持した黒鉛と
を１：５の重量比で混練した後、銅線と一緒に加圧成型
して１０ｍｍ×１０ｍｍ角の電極を作製した。これをＨ
型の電解セル中の１Ｍ水酸化ナトリウム水溶液に浸漬
し、白金板を対極として電圧を印加しながら一酸化炭素
（ＣＯ）をこの電極にバブリングさせると、ＣＯの酸化
による電流が流れた。標準水素電極基準で１００ｍＶの
過電圧を印加した場合、この電流値は０．１ｍＡであっ
た。Example 7 A mixture of finely pulverized Au (3 wt%) / TiO 2 powder prepared in Example 1 and graphite carrying 1 wt% of platinum in a mortar was kneaded at a weight ratio of 1: 5. A 10 mm × 10 mm square electrode was produced by pressure molding together with the wire. This is H
When the electrode was immersed in a 1M aqueous solution of sodium hydroxide in an electrolytic cell of the type and carbon monoxide (CO) was bubbled through this electrode while applying a voltage with a platinum plate as a counter electrode, a current caused by oxidation of CO flowed. When an overvoltage of 100 mV was applied with reference to the standard hydrogen electrode, the current value was 0.1 mA.
【００７３】これに対し、白金を１ｗｔ％担持した黒鉛
だけで電極を作製した場合には、３００ｍＶの過電圧を
印加することにより、電流値は、はじめて０．１ｍＡに
達した。On the other hand, when the electrode was made only of graphite supporting 1 wt% of platinum, the current value reached 0.1 mA for the first time by applying an overvoltage of 300 mV.
【００７４】同様にメタノールを濃度１Ｍになるように
加えた場合に、メタノールの電解酸化によって流れる電
流を１０ｍＡにするためには、白金を１ｗｔ％担持した
黒鉛を用いた電極では５５０ｍＶの過電圧が、Ａｕ（３
ｗｔ％）／ＴｉＯ2 粉末を加えた電極では４５０ｍＶの
過電圧が必要であった。Similarly, when methanol is added to a concentration of 1 M, in order to make the current flowing by electrolytic oxidation of methanol 10 mA, an overvoltage of 550 mV is applied to an electrode using graphite supporting 1 wt% of platinum. Au (3
(wt%) / electrode to which TiO 2 powder was added required an overvoltage of 450 mV.
【００７５】以上の結果から、本発明によるＡｕ（３ｗ
ｔ％）／ＴｉＯ2 粉末は、電極用触媒としても印加電圧
を低下させるという優れた特性を有することが明らかと
なった。From the above results, it can be seen that Au (3w
t%) / TiO 2 powder was found to have excellent characteristics of reducing the applied voltage even as an electrode catalyst.
【００７６】比較例１ 実施例１で用いたと同様の酸化チタン粉末５．０ｇを、
ｐＨ＝２の０．４Ｍ塩化金酸（ＨＡｕＣｌ4 ）水溶液１
０ｍｌ中に浸漬し、攪拌した後、１０時間放置した。Comparative Example 1 5.0 g of the same titanium oxide powder as used in Example 1 was used.
0.4M aqueous solution of chloroauric acid (HAuCl 4 ) 1 at pH = 2
It was immersed in 0 ml, stirred, and allowed to stand for 10 hours.
【００７７】次いで、これを蒸発乾固したものを空気流
通下４００℃で５時間焼成することにより酸化チタンに
金を担持した触媒Ａｕ（３．１ｗｔ％）／ＴｉＯ2 （含
浸法）を得た。高分解能透過型電子顕微鏡観察によれ
ば、この触媒における金は、粒径が３００オングストロ
ーム以上のものばかりであることが明らかになった。Next, this was evaporated to dryness and calcined at 400 ° C. for 5 hours in an air stream to obtain a catalyst Au (3.1 wt%) / TiO 2 (impregnation method) supporting gold on titanium oxide. . Observation with a high-resolution transmission electron microscope revealed that the gold in the catalyst had a particle diameter of 300 Å or more.
【００７８】次いで、この触媒、酸化チタン粉末単独お
よび平均粒径約２００オングストロームの金超微粒子単
独をそれぞれ使用して、水素と一酸化炭素の酸化に対す
る触媒活性を実施例１と同様な条件で測定したところ、
表１のような結果が得られた。Next, using this catalyst, the titanium oxide powder alone and the ultrafine gold particles having an average particle diameter of about 200 angstroms alone, the catalytic activity against the oxidation of hydrogen and carbon monoxide was measured under the same conditions as in Example 1. After doing
The results shown in Table 1 were obtained.
【００７９】 表１ 水素及び一酸化炭素の酸化反応に対する触媒活性の比較 触 媒 活 性 水素の５０％ 一酸化炭素の５０％ 触 媒 酸化率温度 酸化率温度 実施例１ ４１℃ −３５℃ 比較例１ ２１０℃ ３００℃以上＊ 酸化チタン ３００℃以上＊ ３００℃以上＊ 金超微粒子 １００℃ ２９５℃ ＊：温度３００℃までの測定では５０％酸化率に達しな
かったことを意味する。[0079] Table 1 hydrogen and comparative catalytic activity 50% 50% catalytic oxidation rate temperature oxidation index temperature Example 1 41 ° C. -35 ° C. Comparative example carbon monoxide hydrogenation catalytic activity for the oxidation reaction of carbon monoxide 1 210 ° C. 300 ° C. or more * Titanium oxide 300 ° C. or more * 300 ° C. or more * Ultra-fine gold particles 100 ° C. 295 ° C.
【００８０】表１の結果は、従来最も一般的に用いられ
ていた含浸法で金担持触媒を作製しても、本発明による
金超微粒子固定化酸化チタン系酸化物が有する優れた低
温触媒活性は、到底発現されないことを示している。The results in Table 1 show that even when a gold-supported catalyst was prepared by the most commonly used impregnation method, the excellent low-temperature catalytic activity of the ultrafine gold particle-immobilized titanium oxide-based oxide according to the present invention was obtained. Indicates that it is not expressed at all.
【００８１】また、酸化チタン粉末単独では３００℃以
下の温度で酸化触媒活性がほとんどないこと、および金
超微粒子単独では酸化触媒活性が低いことに加え、水素
の酸化に対しての方が一酸化炭素の酸化に対してより低
温で進行することを考え合わせると、本発明の金超微粒
子固定化酸化チタンＡｕ（３ｗｔ％）／ＴｉＯ2 では金
超微粒子と酸化チタンとの特異な複合効果により、極め
て高い酸化触媒活性が発現されているとともに、水素の
酸化よりも一酸化炭素の酸化の方がより低温で進行する
という特性の変化も生じていることが明らかである。In addition to the fact that titanium oxide powder alone has little oxidation catalyst activity at a temperature of 300 ° C. or less, and that ultrafine gold particles alone have low oxidation catalyst activity, the oxidation of hydrogen is more susceptible to monoxide. Considering that the oxidation of carbon proceeds at a lower temperature, considering the unique composite effect of ultrafine gold particles and titanium oxide in the ultrafine gold particle-immobilized titanium oxide Au (3 wt%) / TiO 2 of the present invention, It is evident that a very high oxidation catalytic activity has been developed, and a change in the characteristic has occurred that the oxidation of carbon monoxide proceeds at a lower temperature than the oxidation of hydrogen.
【００８２】このような特異な複合効果が発現されるの
は、実施例１のＡｕ（３ｗｔ％）／ＴｉＯ2 触媒におい
ては、金超微粒子は球状でなく半球状でその平らな底面
で酸化チタン担体に接合しているという特徴ある構造を
有していることによるものと考えられる。これに対し、
比較例１の含浸法で調製した触媒では、金は球状に近い
形状をしており、酸化チタン担体との相互作用が弱く、
金微粒子の凝集が起こりやすいため、触媒活性に乏しい
結果となっている。The reason why such a unique composite effect is exhibited is that in the Au (3 wt%) / TiO 2 catalyst of Example 1, the ultrafine gold particles are not spherical but are hemispherical, and titanium oxide is formed on the flat bottom thereof. This is considered to be due to having a characteristic structure of being bonded to the carrier. In contrast,
In the catalyst prepared by the impregnation method of Comparative Example 1, gold had a nearly spherical shape, weak interaction with the titanium oxide support,
Since the agglomeration of the gold fine particles easily occurs, the result is that the catalytic activity is poor.
【００８３】実施例８ 実施例１と同様な方法で、金の担持量を変えた２種類の
金超微粒子固定化酸化チタン、すなわち、Ａｕ（０．２
５ｗｔ％）／ＴｉＯ2 とＡｕ（２．４ｗｔ％）／ＴｉＯ
2 を作製した。Example 8 In the same manner as in Example 1, two types of titanium oxide immobilized with ultrafine gold particles having different amounts of gold, ie, Au (0.2
5 wt%) / TiO 2 and Au (2.4 wt%) / TiO
2 was produced.
【００８４】この金超微粒子固定化酸化チタン０．３ｇ
を用い、一酸化窒素（ＮＯ）０．１容量％、酸素（Ｏ
2 ）５容量％およびプロピレン（Ｃ3Ｈ6 ）０．０５容
量％を含むヘリウム（Ｈe）混合ガスを１００ｍｌ／分
で流通させて、酸素が過剰に存在する条件における、一
酸化窒素の窒素への還元反応の活性を調べた。なお、比
較のため、金を固定化していない酸化チタンの活性も調
べた。図１にこれらの結果を示す。0.3 g of this ultrafine gold particle-immobilized titanium oxide
Using 0.1% by volume of nitrogen monoxide (NO) and oxygen (O
2 ) A helium (He) mixed gas containing 5% by volume and 0.05% by volume of propylene (C 3 H 6 ) is passed at a flow rate of 100 ml / min. The activity of the reduction reaction was investigated. For comparison, the activity of titanium oxide without immobilizing gold was also examined. FIG. 1 shows these results.
【００８５】この結果から、金超微粒子固定化酸化チタ
ンの場合には、３５０℃で一酸化窒素の２６％が窒素に
還元でき、且つ金の担持量が増えるととともに還元性能
を示す温度範囲が広がること、また金を固定化していな
い酸化チタンでは活性が低いことから、金を担持するこ
とによりはじめて本反応に対して高い活性を示すように
なることが明らかとなった。From these results, in the case of titanium oxide immobilized with ultrafine gold particles, at a temperature of 350 ° C., 26% of nitric oxide can be reduced to nitrogen, and the temperature range in which the amount of gold supported and the reducing performance are shown is reduced. It was clarified that titanium oxide not immobilized with gold had a low activity, and thus, it became apparent that titanium oxide having high activity for this reaction was obtained only by supporting gold.
【図１】本発明方法により得られた金超微粒子固定化酸
化チタンからなる還元触媒の一酸化窒素還元性能を示す
グラフである。FIG. 1 is a graph showing the nitric oxide reduction performance of a reduction catalyst comprising titanium oxide immobilized with ultrafine gold particles obtained by the method of the present invention.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｇ０１Ｎ 27/12 Ｂ０１Ｄ 53/36 ＺＡＢ Ｈ０１Ｍ 4/90 １０２Ｂ １０４Ｚ ──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 6 Identification number Agency reference number FI Technical indication location G01N 27/12 B01D 53/36 ZAB H01M 4/90 102B 104Z
Claims (5)
５０Å以下の金微粒子を固定化したことを特徴とする金
微粒子固定化チタン系金属酸化物からなる触媒燃焼用酸
化触媒。1. A metal oxide containing titanium as a main component having a particle size of 2.
An oxidation catalyst for catalytic combustion comprising a titanium-based metal oxide having gold particles fixed thereon, wherein gold particles having a size of 50 ° or less are fixed.
５０Å以下の金微粒子を固定化したことを特徴とする金
微粒子固定化チタン系金属酸化物からなる一酸化炭素酸
化用触媒。2. A metal oxide containing titanium as a main component having a particle size of 2
A catalyst for carbon monoxide oxidation comprising a titanium-based metal oxide having gold particles immobilized thereon, wherein gold particles having a size of 50 ° or less are immobilized.
５０Å以下の金微粒子を固定化したことを特徴とする金
微粒子固定化チタン系金属酸化物からなる水素酸化用触
媒。3. A metal oxide containing titanium as a main component having a particle size of 2.
A hydrogen oxidation catalyst comprising a titanium-based metal oxide having gold particles fixed thereon, wherein gold particles having a size of 50 ° or less are fixed.
５０Å以下の金微粒子を固定化したことを特徴とする金
微粒子固定化チタン系金属酸化物からなる窒素酸化物還
元用触媒。4. A metal oxide containing titanium as a main component having a particle size of 2.
A nitrogen oxide reduction catalyst comprising a titanium-based metal oxide having gold particles fixed thereon, wherein gold particles having a size of 50 ° or less are fixed.
５０Å以下の金微粒子を固定化したことを特徴とする金
微粒子固定化チタン系金属酸化物からなる電極用触媒。5. A metal oxide containing titanium as a main component having a particle size of 2.
An electrode catalyst comprising a titanium-based metal oxide having gold particles fixed thereon, wherein gold particles having a size of 50 ° or less are fixed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6067803A JP2615418B2 (en) | 1994-03-10 | 1994-03-10 | Oxidation catalyst, reduction catalyst, flammable gas sensor element and catalyst for electrode made of titanium-based metal oxide immobilized with ultrafine gold particles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6067803A JP2615418B2 (en) | 1994-03-10 | 1994-03-10 | Oxidation catalyst, reduction catalyst, flammable gas sensor element and catalyst for electrode made of titanium-based metal oxide immobilized with ultrafine gold particles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH078797A JPH078797A (en) | 1995-01-13 |
| JP2615418B2 true JP2615418B2 (en) | 1997-05-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6067803A Expired - Lifetime JP2615418B2 (en) | 1994-03-10 | 1994-03-10 | Oxidation catalyst, reduction catalyst, flammable gas sensor element and catalyst for electrode made of titanium-based metal oxide immobilized with ultrafine gold particles |
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| JP (1) | JP2615418B2 (en) |
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| US9611413B2 (en) | 2013-06-17 | 2017-04-04 | Bio Epoch Co., Ltd. | Radiator additive and method of use thereof |
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|---|---|---|---|---|
| EP0827779A4 (en) * | 1996-03-21 | 1999-06-30 | Agency Ind Science Techn | Catalysts for partial oxidation of hydrocarbons and method of partial oxidation of hydrocarbons |
| KR100512672B1 (en) * | 1996-07-01 | 2005-12-21 | 다우 글로벌 테크놀로지스 인크. | Catalyst composition, process of regenerating the same and process of preparing an olefin oxides using the same |
| BG62723B1 (en) * | 1997-09-29 | 2000-06-30 | "Ламан-Консулт"Оод | Gold catalyst and its application in fuel components |
| JP4000392B2 (en) * | 1997-11-05 | 2007-10-31 | 独立行政法人産業技術総合研究所 | Catalyst for partial oxidation of hydrocarbons and process for producing oxygenated organic compounds |
| EP1177041B1 (en) | 1999-04-08 | 2004-02-11 | Dow Global Technologies Inc. | Process for the hydro-oxidation of olefins to olefin oxides using oxidized gold catalyst |
| WO2003043732A1 (en) * | 2001-11-23 | 2003-05-30 | Lidun An | Supported gold catalyst useful for catalytic oxidation of co at low temperature |
| WO2004101864A1 (en) | 2003-05-16 | 2004-11-25 | Hideo Yoshida | Anodic oxidation method and production method for titanium oxide coating and method of supporting catalyst |
| CA2540036C (en) | 2003-09-26 | 2013-10-22 | 3M Innovative Properties Company | Nanoscale gold catalysts, activating agents, support media, and related methodologies useful for making such catalyst systems especially when the gold is deposited onto the support media using physical vapor deposition |
| EP1776187A1 (en) * | 2004-07-06 | 2007-04-25 | University College Cardiff Consultants, Ltd. | Supported gold catalysts |
| JP2006210135A (en) * | 2005-01-28 | 2006-08-10 | Sony Corp | Catalyst electrode material, catalyst electrode, manufacturing method thereof, support material for electrode catalyst and electrochemical device |
| JP4197683B2 (en) | 2005-03-15 | 2008-12-17 | 株式会社東芝 | Catalyst for fuel cell electrode, fuel cell electrode, membrane electrode assembly, and fuel cell |
| WO2006100982A1 (en) * | 2005-03-18 | 2006-09-28 | Nippon Shokubai Co., Ltd. | Electrode catalyst for fuel cell |
| JP5055557B2 (en) * | 2005-12-19 | 2012-10-24 | 国立大学法人横浜国立大学 | Oxygen reduction electrode for direct fuel cell |
| JP5378669B2 (en) * | 2007-09-27 | 2013-12-25 | Ｊｘ日鉱日石エネルギー株式会社 | Membrane electrode assembly, fuel cell and fuel cell system |
| JP5134599B2 (en) * | 2008-08-25 | 2013-01-30 | 独立行政法人産業技術総合研究所 | Catalyst for CO gas sensor, paste, and CO gas sensor |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JPS5843239A (en) * | 1981-09-09 | 1983-03-12 | Agency Of Ind Science & Technol | Manufacture of colloid carrying type solid catalyst |
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- 1994-03-10 JP JP6067803A patent/JP2615418B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9611413B2 (en) | 2013-06-17 | 2017-04-04 | Bio Epoch Co., Ltd. | Radiator additive and method of use thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH078797A (en) | 1995-01-13 |
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