JPH0753577B2 - Method for producing titanium-based oxide with ultrafine gold particles immobilized - Google Patents
Method for producing titanium-based oxide with ultrafine gold particles immobilizedInfo
- Publication number
- JPH0753577B2 JPH0753577B2 JP4309705A JP30970592A JPH0753577B2 JP H0753577 B2 JPH0753577 B2 JP H0753577B2 JP 4309705 A JP4309705 A JP 4309705A JP 30970592 A JP30970592 A JP 30970592A JP H0753577 B2 JPH0753577 B2 JP H0753577B2
- Authority
- JP
- Japan
- Prior art keywords
- gold
- titanium
- metal oxide
- oxide
- ultrafine
- 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 123
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 title claims description 102
- 229910052737 gold Inorganic materials 0.000 title claims description 102
- 239000010936 titanium Substances 0.000 title claims description 82
- 229910052719 titanium Inorganic materials 0.000 title claims description 81
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 title claims description 78
- 239000002245 particle Substances 0.000 title claims description 44
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 229910044991 metal oxide Inorganic materials 0.000 claims description 71
- 150000004706 metal oxides Chemical class 0.000 claims description 69
- 239000007864 aqueous solution Substances 0.000 claims description 48
- 150000002344 gold compounds Chemical class 0.000 claims description 29
- 239000007788 liquid Substances 0.000 claims description 21
- 239000000243 solution Substances 0.000 claims description 20
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 12
- 239000003638 chemical reducing agent Substances 0.000 claims description 8
- 230000002378 acidificating effect Effects 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 7
- 239000001569 carbon dioxide Substances 0.000 claims description 6
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 6
- 239000003054 catalyst Substances 0.000 description 40
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 36
- 238000000034 method Methods 0.000 description 35
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 33
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 30
- 229910002091 carbon monoxide Inorganic materials 0.000 description 30
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 27
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 24
- 239000007789 gas Substances 0.000 description 24
- WDZVNNYQBQRJRX-UHFFFAOYSA-K gold(iii) hydroxide Chemical compound O[Au](O)O WDZVNNYQBQRJRX-UHFFFAOYSA-K 0.000 description 24
- 229910021505 gold(III) hydroxide Inorganic materials 0.000 description 22
- 238000007254 oxidation reaction Methods 0.000 description 20
- 238000006243 chemical reaction Methods 0.000 description 15
- 230000003647 oxidation Effects 0.000 description 15
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 14
- 239000000843 powder Substances 0.000 description 13
- 239000011882 ultra-fine particle Substances 0.000 description 13
- 239000001257 hydrogen Substances 0.000 description 12
- 229910052739 hydrogen Inorganic materials 0.000 description 12
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 12
- 229910010413 TiO 2 Inorganic materials 0.000 description 11
- 239000000725 suspension Substances 0.000 description 11
- 230000010718 Oxidation Activity Effects 0.000 description 10
- 238000006722 reduction reaction Methods 0.000 description 10
- 238000003756 stirring Methods 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000002253 acid Substances 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 8
- 230000003197 catalytic effect Effects 0.000 description 8
- 150000002431 hydrogen Chemical class 0.000 description 8
- 238000001556 precipitation 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
- 229910000029 sodium carbonate Inorganic materials 0.000 description 7
- 229910002367 SrTiO Inorganic materials 0.000 description 6
- 239000002131 composite material Substances 0.000 description 6
- 150000001875 compounds Chemical class 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 229910052697 platinum Inorganic materials 0.000 description 6
- 230000009467 reduction Effects 0.000 description 6
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 5
- 150000002500 ions Chemical class 0.000 description 5
- 239000002244 precipitate Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 4
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 238000000151 deposition Methods 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
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 3
- 235000011114 ammonium hydroxide Nutrition 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 230000008021 deposition Effects 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
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 230000001603 reducing effect Effects 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- DLFVBJFMPXGRIB-UHFFFAOYSA-N Acetamide Chemical compound CC(N)=O DLFVBJFMPXGRIB-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-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
- 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
- 238000002441 X-ray diffraction Methods 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
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-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
- 239000006185 dispersion Substances 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 150000002343 gold Chemical class 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
- 239000000463 material Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen 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
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 description 2
- -1 titanium metal oxide Chemical class 0.000 description 2
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 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 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 230000010757 Reduction Activity Effects 0.000 description 1
- 102000005393 Sodium-Potassium-Exchanging ATPase Human genes 0.000 description 1
- 108010006431 Sodium-Potassium-Exchanging ATPase Proteins 0.000 description 1
- 229910002370 SrTiO3 Inorganic materials 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 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
- 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
- 230000002301 combined effect Effects 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 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
- 238000011161 development Methods 0.000 description 1
- HPNMFZURTQLUMO-UHFFFAOYSA-N diethylamine Chemical compound CCNCC HPNMFZURTQLUMO-UHFFFAOYSA-N 0.000 description 1
- 150000004683 dihydrates Chemical class 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000006260 foam Substances 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
- 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
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 239000012702 metal oxide precursor Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical class [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 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
- 238000001420 photoelectron spectroscopy Methods 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- NNFCIKHAZHQZJG-UHFFFAOYSA-N potassium cyanide Chemical compound [K+].N#[C-] NNFCIKHAZHQZJG-UHFFFAOYSA-N 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
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 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
- 238000012360 testing method Methods 0.000 description 1
- 150000003608 titanium 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
【発明の詳細な説明】本発明は、金超微粒子固定化チタ
ン系酸化物の製造法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a titanium oxide on which ultrafine gold particles are immobilized.
【０００１】本発明方法により得られる金超微粒子固定
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、電極用触媒などとして有用である。The ultrafine gold particle-immobilized titanium oxide obtained by the method of the present invention is useful as an oxidation catalyst, a reduction catalyst, a combustible gas sensor element, an electrode catalyst, and the like.
【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 Ultrafine gold particles having a particle size of about 0.1 μm or less are known to exhibit unique physical and chemical properties different from those of 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等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, since the ultrafine particles have a large surface energy and are very easily solidified, they are difficult to handle. In particular, gold has a lower melting point (gold: 1063 ° C., platinum: 1769 ° C., palladium 1550 ° C.) than other noble metals such as Pt and Pd, and because the bonds between metals are strong, ultrafine particles easily aggregate. However, it has been difficult to fully bring out the characteristics of the 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。Therefore, there has been a demand for development of a method for supporting or immobilizing ultrafine gold particles on a carrier in a uniformly dispersed state. For example, water-soluble compounds such as manganese, iron, cobalt, nickel and copper, and gold. A method for 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 (JP-A-60-2).
38148). However, with 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. Further, in this method, since 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 a drawback that the usage form is limited. However, there is 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 of immersing the carrier in an aqueous solution containing gold and using urea and / or acetamide to deposit ultrafine gold particles on the carrier (Japanese Patent Application No. 60-1).
92775). However, in this method, it is essential to precisely control the conditions of gold precipitation, and
It has a drawback that it takes a long time of several hours to carry it. Further, since only a part of the gold component can be precipitated and deposited from the gold aqueous solution, there are disadvantages that the utilization rate of gold is low and the manufacturing cost is high. Furthermore, the obtained gold precipitates are non-uniform and tend to form coarse lumps, and it is difficult to control the particle size of the gold precipitates.
【０００６】[0006]
【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した複合材料を簡単な方法で効率よ
く得る方法を提供することを主な目的とする。Therefore, the present invention provides a method for efficiently obtaining a composite material in which fine gold particles are uniformly and firmly fixed on a carrier composed of an oxide containing titanium as a main component, by a simple method. The main purpose is to do.
【０００７】[0007]
【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の条件に調整する場合には、
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。In view of the above problems of the prior art, the present inventor has uniformly and firmly fixed ultrafine gold particles on a carrier composed of a metal oxide containing titanium as a main component. We have conducted intensive studies to efficiently prepare the composite material by the simple method. Then, as a result of further research focusing on the precipitation / dissolution reaction of gold complex ions in an alkaline aqueous solution and the adsorption behavior of metal oxides on the surface, as a result, the pH value of the aqueous solution and the gold water-soluble salts and other When adjusting the addition method of the additive of to specific conditions,
It has been found that gold hydroxide or gold ultrafine particles can be uniformly and highly efficiently deposited on the surface of a metal oxide containing titanium as a main component. Further, when gold hydroxide is deposited, it is possible to uniformly and firmly fix and support ultrafine gold particles on the metal oxide containing titanium as a main component by heating the gold hydroxide. I found it. Furthermore, the obtained gold ultrafine particles-immobilized titanium oxide is used as an oxidation catalyst, a reduction catalyst, a combustible gas sensor element,
It has been found to be extremely useful in applications such as electrode catalysts.
【０００８】即ち、本発明は、以下に示す金超微粒子固
定化チタン系酸化物の製造法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を含有するｐＨ７
〜１１の液に、上記ｐＨ範囲を維持しつつ金化合物水溶
液を滴下した後、該金属酸化物を１００〜８００℃に加
熱することを特徴とする金超微粒子固定化チタン系酸化
物の製造方法。 ２．金化合物を溶解し且つチタンを主成分とする金属酸
化物を含有するｐＨ７〜１１の液に、上記ｐＨ範囲を維
持しつつ還元剤を滴下して金属酸化物表面に金超微粒子
を析出させることを特徴とする金超微粒子固定化チタン
系酸化物の製造方法。 ３．金化合物を溶解し且つチタンを主成分とする金属酸
化物を含有するｐＨ１１以上の液に、二酸化炭素ガスを
吹き込むか、または酸性水溶液を滴下して、ｐＨ７〜１
１とした後、該金属酸化物を１００〜８００℃に加熱す
ることを特徴とする金超微粒子固定化チタン系酸化物の
製造方法。That is, the present invention provides the following method for producing a titanium-based oxide on which ultrafine gold particles are immobilized; PH 7 containing a metal oxide containing titanium as a main component
To 11 liquid, an aqueous solution of a gold compound is added dropwise while maintaining the above pH range, and then the metal oxide is heated to 100 to 800 ° C., a method for producing a titanium-based oxide with ultrafine gold particles immobilized thereon. . 2. To deposit ultra-fine gold particles on the surface of a metal oxide by adding a reducing agent dropwise to a liquid having a pH of 7 to 11 in which a gold compound is dissolved and containing a metal oxide containing titanium as a main component, while maintaining the above pH range. A method for producing a titanium-based oxide on which ultrafine gold particles are immobilized. 3. Carbon dioxide gas is blown into a liquid containing a metal oxide containing titanium as a main component and containing titanium as a main component and having a pH of 11 or more, or an acidic aqueous solution is dropped to adjust the pH to 7-1.
After that, the metal oxide is heated to 100 to 800 [deg.] C., and a method for producing a titanium-based oxide with ultrafine gold particles immobilized thereon.
【０００９】本発明による金超微粒子固定化チタン系酸
化物は、以下に挙げる方法で得ることができる。 （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。The ultrafine gold particle-immobilized titanium oxide according to the present invention can be obtained by the following methods. (I) First method: First, the pH of a liquid containing a metal oxide containing titanium as a main component as a carrier is adjusted to 7 to 11, preferably 7.5 to 10, and the gold compound is added to this aqueous solution with stirring. The aqueous solution is dropped to deposit gold hydroxide on the metal oxide containing titanium as a main component. Then, the titanium-based metal oxide to which the gold hydroxide is attached is heated to 100 to 800 ° C. to deposit and fix gold ultrafine particles on the surface of the titanium-based oxide.
【００１０】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, not only TiO 2 but also, for example, Fe is used as the metal oxide containing titanium as a main component.
A titanium-containing composite oxide such as TiO 3 , CaTiO 3 , or SrTiO 3 can be used. The “oxide containing titanium as a main component” in the present invention is a so-called “metal oxide precursor” such as a carbonate or hydroxide capable of forming a titanium oxide or a titanium-containing metal oxide by heating. Shall also be included.
【００１１】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酸化物を固
定した状態で用いることもできる。The shape of titanium oxide or titanium-containing metal oxide (both of which may be simply referred to as titanium oxide in the present specification) is not particularly limited, and is not limited to powder form. It can also be used after being molded into various shapes. Further, it is also possible to use the titanium oxide fixed on a support such as ceramics such as alumina, silica, magnesia, cordierite or the like, foams of various metals, honeycombs, pellets and the like.
【００１２】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、酸化物担体の量は特に限
定されない。The amount of titanium-based metal oxide added to water is
There is no particular limitation. For example, when a powdery oxide is used, it may be in an amount such that it can be uniformly dispersed or suspended in water, and usually about 10 to 200 g / l is suitable. When the titanium-based metal oxide is used as a molded body, the amount of the oxide carrier is not particularly limited as long as the surface of the molded body can be sufficiently contacted with the aqueous solution, depending on the shape of the molded body.
【００１３】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〔（Ｃ2 Ｈ5 ）2 ＮＨ・ＡｕＣｌ3 〕など
の水溶性金塩を用いることができる。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
〜０．００１ｍｏｌ／ｌ程度が適当である。Gold compounds used in the form of an aqueous solution include chloroauric acid (HAuCl 4 ), sodium chloroaurate (NaAuCl 4 ), gold cyanide (AuCN), potassium cyanide {K [Au (CN) 2 ], And water-soluble gold salts such as diethylamine trichloroaurate [(C 2 H 5 ) 2 NH.AuCl 3 ]. The concentration of the gold compound aqueous solution used for dropping is not particularly limited, but is usually 0.1.
An amount of about 0.001 mol / l is suitable.
【００１４】金属酸化物を含む液を所定の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 pH of the liquid containing the metal oxide to a predetermined range, an alkali compound such as sodium carbonate, sodium hydroxide, potassium carbonate or ammonia is usually used.
【００１５】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
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適宜滴下速度を調節すれ
ばよい。The aqueous solution of the gold compound needs to be gradually added dropwise with stirring so that large precipitation of gold hydroxide does not occur due to a rapid reaction. Usually, the dropping time is set to 3 depending on the dropping amount. It may be within a range of about 60 minutes, and the dropping rate may be appropriately adjusted so that large precipitation of hydroxide does not occur.
【００１６】滴下時のチタン系酸化物含有液の液温は、
２０〜８０℃程度が適当である。The liquid temperature of the titanium-containing oxide-containing liquid at the time of dropping is
About 20 to 80 ° C is suitable.
【００１７】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 dropping amount of the aqueous solution of the gold compound is determined by the amount of gold superparticles supported on the titanium-based metal oxide. The upper limit of the supported amount varies depending on the type of titanium-based metal oxide used, its shape, specific surface area, etc., but it is usually 0.1 to 10% by weight.
【００１８】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 gold compound aqueous solution is gradually dropped, even if gold hydroxide is formed in the liquid phase at the time of dropping, it is immediately re-dissolved, and the re-dissolved gold compound is titanium-based. The metal oxide is adsorbed on the surface of the metal oxide, and the titanium-based metal oxide serves as a nucleus, and gold adheres to the surface as hydroxide. Therefore, the dropped gold compound does not precipitate in the aqueous solution.
【００１９】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。Gold is usually present as a complex ion having a negative charge in the dispersion or suspension in which the gold compound aqueous solution is dropped. Therefore, in order to increase the efficiency of gold deposition on titanium-based metal oxides, the pH of the dispersion or suspension should be lower than the equipotential point of the titanium-based metal oxide carrier, that is, on the acidic side, titanium-based metal should be used. It is preferable to adjust the surface of the oxide to have a positive charge. Further, even when the pH is closer to the alkaline side than the equipotential point, it is appropriate to set the pH value as close to the equipotential point as possible, and preferably the pH value is about 0.5 higher than the pH value at the equipotential point. Use below the value.
【００２０】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。Usually, the gold compound easily adheres to the titanium-based metal oxide as a hydroxide at a pH of about 7 to 11, but when adhering, 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 liquid. Therefore, in order to obtain uniform precipitates of ultrafine gold particles, it is preferable to appropriately drop an aqueous alkaline solution to suppress the fluctuation of the pH of the mixed reaction solution. In particular, when the reaction is carried out at a low pH of about pH 7 to 8, it is preferable to add the gold compound aqueous solution and the alkaline aqueous solution at the same time so that the pH does not become 7 or less.
【００２１】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。（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
化物を含有する水溶液に、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。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 distributed on the titanium-based metal oxide. It precipitates as ultrafine particles and is fixed to strength.
The heating time is usually about 1 to 24 hours. (II)
Second method: A gold compound is dissolved, the pH is 7 to 11 (preferably pH 7.5 to 10), and an aqueous solution of a reducing agent is added dropwise to the aqueous solution containing a titanium-based metal oxide while stirring, By reducing and depositing gold on the surface of titanium-based metal oxides,
Immobilize ultrafine gold particles.
【００２２】金化合物、チタン系金属酸化物及びｐＨ調
整用のアルカリ性化合物は、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、１×１０-2〜１×１０-5ｍｏｌ／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。As the gold compound, titanium-based metal oxide and alkaline compound for pH adjustment, the same compounds as in the first method can be used. The amount of titanium-based metal oxide added may be the same as in the first method. In the second method, it is appropriate that the concentration of the gold compound in the liquid is about 1 × 10 −2 to 1 × 10 −5 mol / l. The liquid temperature during the reaction of the titanium-based metal oxide-containing aqueous solution is preferably about 0 to 80 ° C.
【００２３】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 addition amount of the reducing agent aqueous solution is appropriately 1.5 to 10 times the stoichiometrically required amount. It is necessary to gradually add the reducing agent aqueous solution so as not to cause abrupt deposition of gold in the reaction solution, and usually it may be added dropwise over a period of about 3 to 60 minutes.
【００２４】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 dropping the reducing agent solution, the gold compound adsorbed on the surface of the titanium-based metal oxide is reduced to gold and firmly adheres.
【００２５】金属酸化物としてＣａＴｉＯ3 、ＳｒＴｉ
Ｏ3 等を用いる場合には、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。CaTiO 3 , SrTi as metal oxide
When O 3 or the like is used, the gold compound adheres to the metal oxide with high efficiency even at a high pH value of about 11. On the other hand, when titanium oxide (TiO 2 ) is used, at such a high pH value, the surface of the metal oxide is strongly negatively charged, and the adhesion efficiency of the gold compound often deteriorates. In such a case, it is preferable to set the pH of the reaction solution to about 7 to 8 and to reduce the negative charge amount to some extent even when the metal oxide is positively charged or negatively charged. . When the pH of the reaction solution is set to 7 to 8, an alkaline aqueous solution is added at the same time as the reducing agent is added to the reaction solution so that the pH of the reaction solution does not decrease, so that the reduction deposition rate of gold is kept substantially constant. Preferably.
【００２６】なお、得られた金超微粒子固定化チタン系
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
子固定化チタン系酸化物を加熱しておくことが好まし
い。 （III ）第３方法：金化合物を溶解し、ｐＨ１１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、水溶液の
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。The obtained ultrafine gold particle-immobilized titanium oxide can be used as it is at room temperature. However, when it is used at high temperature, in order to ensure stability at high temperature,
Prior to use, it is preferable to once heat the ultrafine gold particle fixed titanium-based oxide to a temperature around the use temperature. (III) Third method: A carbon dioxide gas is blown into a liquid which dissolves a gold compound and has a pH of 11 or more (preferably pH 11 to 12) and contains a titanium-based metal oxide.
Alternatively, the acidic aqueous solution is gradually dropped with stirring to reduce the pH of the aqueous solution to 7 to 11, and gold hydroxide is attached to the surface of the titanium-based metal oxide. Next, this titanium-based metal oxide is heated to 100 to 800 ° C. to deposit ultrafine gold particles on the surface of the titanium-based metal oxide.
【００２７】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 metal oxide and alkaline compound used may be the same as in the first method. The liquid temperature of the liquid containing the titanium-based metal oxide is 20 to
It may be about 80 ° C.
【００２８】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, the gold compound must be present as a complex ion in which hydroxyl groups are excessively bonded, in a state of being dissolved in a liquid containing a titanium-based metal oxide.
Therefore, depending on the gold compound used, the pH of the titanium-based metal oxide-containing solution is adjusted so that the pH is 11 or more and the gold compound is dissolved as a hydroxyl group-containing complex ion.
【００２９】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。Carbon dioxide gas is blown into the liquid adjusted to such a state, or an acidic aqueous solution is gradually dropped to gradually decrease the pH of the solution to pH 7 to 11 to obtain a titanium-based material. Gold hydroxide is deposited using the metal oxide as a nucleus and adheres to the surface of the titanium-based metal oxide.
【００３０】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 rate of the carbon dioxide gas is not particularly limited as long as the reaction solution is uniformly bubbled.
【００３１】酸性水溶液としては、硝酸、塩酸、硫酸、
酢酸などのの水溶液が使用でき、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ｐＨ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,
Aqueous solution such as acetic acid can be used, 1 × 10 -1 to 1 × 10
It may be used at a concentration of about -3 mol / l. The dropping amount may be in the range where the pH of the liquid containing the titanium-based metal oxide does not fall below 7. The dropping rate may be appropriately determined according to the dropping amount in the dropping time range of about 3 to 60 minutes so that large precipitation of gold hydroxide does not occur.
【００３２】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 has adhered to 100 to 800 ° C., the adhered gold hydroxide is decomposed and the gold is evenly distributed on the titanium-based metal oxide. Ultrafine particles are deposited and firmly fixed. The heating time is usually about 1 to 24 hours.
【００３３】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-mentioned methods, a solution containing the titanium-based metal oxide for about 30 minutes to 2 hours after the dropping or blowing is completed so that the gold compound is sufficiently adhered to the titanium-based metal oxide. It is preferable to carry out stirring.
【００３４】本発明の各方法によれば、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 methods of the present invention, it is possible to immobilize ultrafine gold particles having a particle size of about 500 angstroms or less and a uniform particle size on a titanium-based metal oxide, which has not been obtained by a conventional method. It is possible to uniformly and strongly support ultrafine gold particles of about 250 Å or less on the titanium-based metal oxide. In any of the above-mentioned 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.
【００３５】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-mentioned methods, the titanium-based metal oxide may be used not only in the powder state but also in a preformed state or fixed to various supports. For example, ultrafine gold particles can be directly immobilized on a sintered body in which a platinum wire or the like is embedded, a sintered body of titanium-based metal oxide as an electrode to which an electric lead is connected, or the like.
【００３６】本発明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各種のチタン
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 ultrafine gold particles-immobilized titanium-based metal oxide obtained by the present invention is obtained by uniformly supporting fine gold ultrafine particles on various titanium-based metal oxides and can be used for various purposes. .
【００３７】例えば、本発明の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 ultrafine gold particle-immobilized titanium metal oxide of the present invention can burn a wide range of concentration of fuel such as hydrogen, carbon monoxide, methanol, and propane at a relatively low temperature of 300 ° C. or lower, It is useful as a catalyst for various combustion type heaters and kitchen heaters. Further, it can be used as an exhaust gas purifying catalyst for oil stoves, oil fan heaters, gas fan heaters, or as an air purifying catalyst filter for air conditioners. In addition, it is also useful as a catalyst body for solvent oxidation treatment in the paint industry, a catalyst body for purifying factory exhaust gas, and the like.
【００３８】また、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。It is also useful as a catalyst for reducing nitrogen oxides such as NO and NO 2 with hydrogen, carbon monoxide and the like.
【００３９】さらに、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, hydrogen, carbon monoxide, methanol,
It is also useful as a combustible gas sensor element for hydrocarbons and the like.
【００４０】さらにまた、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, it is useful as a fuel cell for hydrogen, carbon monoxide, methanol, hydrocarbons and the like, and as an electrode catalyst for electrochemical reaction of these gases.
【００４１】[0041]
【発明の効果】本発明では、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。INDUSTRIAL APPLICABILITY According to the present invention, it is possible to fix and support ultrafine gold particles on titanium-based metal oxides of various forms in a short time, and the utilization efficiency of gold is high. The amount can be saved.
【００４２】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 the titanium-based metal oxide fixed to the preformed sintered body or various supports, the ultrafine gold particles can be directly attached to the gas sensor element or the electrode produced by the conventional process. By immobilizing ultrafine gold particles,
The performance of these materials can be easily improved.
【００４３】[0043]
【実施例】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 into which 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 chloroauric acid solution was 7.5 × 10 −3 M, and the dropping amount was 100 ml. The concentration of the sodium carbonate aqueous solution is 0.1 M, and the pH of the suspension is 7-8.
Was added dropwise.
【００４４】滴下終了後、懸濁液の攪拌を１時間続け、
酸化チタン表面上に水酸化金（III）（Ａｕ（Ｏ
Ｈ3 ））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 the completion of dropping, stirring of the suspension is continued for 1 hour,
Gold (III) hydroxide (Au (O
H 3)) to precipitate. When sodium hydroxide was added to the colorless and transparent supernatant to adjust the pH to 12 and formalin was added, the change from colorless to slightly purple was caused by the precipitation of gold colloid. It was found that most of the gold was deposited on the titanium oxide.
【００４５】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 gold hydroxide is deposited is washed with water, dried, and further calcined in air at 400 ° C. for 3 hours to thermally decompose the gold hydroxide, whereby a catalyst having gold supported on the titanium oxide surface is obtained. Au (3 wt%) / TiO 2 was obtained.
It was confirmed by a high resolution transmission electron microscope that the gold supported on the surface of the catalyst was in a metallic state and had a uniform particle size and an average particle size of 35 angstroms or less.
【００４６】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）を１容量％含む空気混合ガスを６７ｍｌ／分で流通
させて、一酸化炭素に対する酸化活性を調べた。Next, 0.2 g of the above-mentioned catalyst sieved to 40-70 mesh was used to prepare carbon monoxide (C
An air mixed gas containing 1% by volume of O) was circulated at 67 ml / min to examine the oxidation activity for carbon monoxide.
【００４７】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 revealed that the oxidation reaction rate was 50% at -35 ° C, and that the catalyst Au / TiO 2 exhibited high carbon monoxide oxidation activity even at a low temperature of 0 ° C or lower.
【００４８】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。 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。Further, when an experiment was conducted under the same conditions as above except that CO was replaced by hydrogen, an oxidation reaction rate of 41% was exhibited at 41 ° C., and the catalyst Au / TiO 2 exhibited a high hydrogen oxidation activity even at around room temperature. It became clear. Example 2 5.0 g of strontium titanate (SrTiO 3 ) powder sieved to 40-70 mesh was suspended in 250 ml of water.
【００４９】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は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時間続け、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 chloroauric acid (HAuCl 4 ) solution and sodium carbonate (N
a 2 CO 3 ) aqueous solution was simultaneously added dropwise 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 0.1M, and the pH of the suspension is 8 to
It was dripped so that it was maintained at 9. After the completion of dropping, 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 clear supernatant liquid to adjust the pH to 12, and formalin was added, but the color change due to the precipitation of gold was slight, and most of the gold in the solution was on strontium titanate. It was found to have precipitated.
【００５０】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
Was washed with water, dried, and further calcined in air at 400 ° C. for 3 hours to thermally decompose gold hydroxide to obtain SrTiO 3.
3 Catalyst Au (1 wt%) / SrTi with gold supported on the surface
O 3 was obtained.
【００５１】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。Gold supported on the surface of the catalyst must be in a metallic state and have a particle size of 100 angstroms or less.
It was confirmed by line photoelectron spectroscopy and X-ray diffraction.
【００５２】次いで、上記触媒を０．２ｇ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。 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、水溶液が塩化金酸の存在により、水溶液は黄
色透明であったが、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、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。Next, using 0.2 g of the above catalyst, 67 ml / air mixed gas containing 1% by volume of carbon monoxide (CO) was used.
The mixture was circulated in minutes to examine the oxidation activity of carbon monoxide. As a result, it became clear that Au (1 wt%) / SrTiO 3 exhibits a high carbon monoxide oxidation activity near room temperature. Example 3 2.0 g of titanium oxide (TiO 2 ) powder was suspended in 100 ml of an aqueous ammonia solution having a pH of 7 in which 0.21 g of chloroauric acid (HAuCl 4 .4H 2 O) was dissolved. While vigorously stirring this suspension at room temperature, 3.5 ml of a 3.7 wt% aqueous solution of hydrazine hydrochloride in a dropping funnel and 10 wt% aqueous ammonia were simultaneously added little by little over 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 was completed, the supernatant became colorless and transparent, and the gold in the liquid phase was removed. It did not become red and blue transparent indicating the presence of colloidal particles. This confirmed that gold was reduced and deposited only on the surface of titanium oxide (TiO 2 ).
【００５３】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 completion of the reduction reaction, the suspension is filtered, washed, and the solid content is dried under vacuum for 24 hours and then dried in air.
Baking was performed at 0 ° C. for 5 hours to obtain titanium oxide (TiO 2 ) having 5% by weight of gold fixed and supported thereon.
【００５４】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。 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をそれぞれ３０分間か
けて徐々に滴下した。Using 0.2 g of titanium oxide with this gold fixed, 67 m of an air mixed gas containing 1% by volume of methanol was used.
It 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. Example 4 Titanium oxide (TiO 2 ) powder was finely pulverized with a wet mill, and a small amount of polyvinyl alcohol was added to form a paste. This was applied to a cordierite honeycomb of 5 cm × 5 cm × 2 cm and fired in air at 400 ° C. for 3 hours. The obtained honeycomb is treated with a sodium carbonate aqueous solution having a pH of 8.5 to 200 m.
l, and circulate and stir the aqueous solution with a circulating pump,
Sodium chloroaurate dihydrate [Na (AuCl 4 ) ・ 2
H 2 O] 50 ml of an aqueous solution of 0.30 g and pH 9
50 ml of the sodium carbonate aqueous solution of was gradually added dropwise over 30 minutes.
【００５５】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。Also in this case, as in the case of the first embodiment,
The supernatant liquid after the completion of the reduction reaction is colorless and transparent, and even if potassium hydroxide is added to adjust the pH to 12 and formalin is excessively added, only a slight change in color due to the precipitation of gold does not occur. It was confirmed that gold was deposited as a hydroxide only on the surface of the supported titanium oxide.
【００５６】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。Next, the honeycomb in which gold was precipitated was taken out from the aqueous solution, washed, dried at 120 ° C. for 12 hours, and calcined in air at 500 ° C. for 3 hours to obtain a gold oxide-supported titanium oxide-supported honeycomb catalyst. It was confirmed by an X-ray diffraction method that the gold supported on the catalyst surface was in a metallic state and had a particle size of about 70 Å.
【００５７】次いで、上記触媒にＣＯを１容量％および
水分を１容量％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, an air mixed gas containing 1% by volume of CO and 1% by volume of water was passed through the catalyst at a rate of 10 l / min to examine the oxidation activity for carbon monoxide. As a result, it was revealed that an oxidation reaction rate of 80% was obtained at 35 ° C., and the titanium ultrafine particles-immobilized titanium oxide-supported honeycomb catalyst exhibited a high carbon monoxide oxidation activity at room temperature.
【００５８】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Ｎ
2 に、３００℃ではＮＯの７０％がＮ2 に還元され、本
発明方法により得られ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。 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。A helium gas containing 1000 ppm of CO and 1000 ppm of nitric oxide (NO) was passed through the catalyst at a flow rate of 10 l / min to examine the reducing activity for NO. As a result, 25% of NO is N at 250 ° C.
2 , 70% of NO is reduced to N 2 at 300 ° C., and the gold ultrafine particle-immobilized titanium oxide-supported honeycomb catalyst obtained by the method of the present invention exhibits high nitric oxide reduction activity in a temperature range of 250 ° C. or higher. It became clear. Example 5 p containing 5.0 g of calcium titanate (CaTiO 3 ) granules, 1.25 × 10 −4 mol of chloroauric acid (HAuCl 4 ) and 1.0 × 10 −2 mol of potassium hydroxide (KOH)
It was suspended in 500 ml of an alkaline aqueous solution of H11.5. To this suspension, 0.1 M nitric acid was added dropwise at a rate of 2 ml / min to lower the pH of the solution to 8.
Gold hydroxide (III) [Au (OH) 3 ] on the aTiO 3 surface
Was deposited. This is washed with water, dried, and then in air 4
Baking at 00 ℃ for 3 hours, pyrolyzing gold hydroxide, Ca
Catalyst Au with gold supported on TiO 3 surface (0.5 wt%)
/ CaTiO 3 was obtained.
【００５９】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。 参考例１ 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。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 to examine the oxidation activity of carbon monoxide. As a result, it showed an oxidation reaction rate of 85% at 90 ° C. From this,
It became clear that this catalyst Au / CaTiO 3 exhibits a high carbon monoxide oxidation activity at a temperature of 100 ° C. or lower. Reference Example 1 Au (1 wt%) / SrTiO 3 produced in Example 2 was used as a film-shaped sintered body, and two electrodes were connected so that the electric resistance could be measured. In other words, two gold wires for electrodes (diameter: 0.05 mm) are arranged on the surface of an alumina substrate (thickness: 0.5 mm) of 10 mm × 10 mm so as to have an interval of 1.0 mm,
About 1 to 500 mg of Au (1 wt%) / SrTiO3 powder
ml of water was added, and a paste prepared by finely pulverizing in a mortar was applied. This was dried at 120 ° C. for 12 hours and then calcined in air at 400 ° C. for 1 hour to obtain a film-shaped sintered body with electrodes, which was used as a flammable gas sensor element.
【００６０】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。 参考例２ 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。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) of air containing the test gas. When the temperature of the gas sensor element is 300 ° C., Rair / Rgas for carbon monoxide, hydrogen, and propane contained in 100 ppm in air are 8.5, 2.2, and 1.5, respectively. It has been revealed that it exhibits particularly excellent response sensitivity. Reference Example 2 Au (3 wt%) / TiO 2 powder prepared in Example 1 was finely pulverized in a mortar and graphite supporting 1 wt% of platinum was kneaded at a weight ratio of 1: 5, and then mixed with a copper wire. By pressure molding, a 10 mm × 10 mm square electrode was produced. This is H
When a carbon monoxide (CO) was bubbled through this electrode while it was immersed in a 1 M aqueous sodium hydroxide solution in an electrolysis cell of the type and a voltage was applied using a platinum plate as a counter electrode, a current flowed due to the oxidation of CO. When an overvoltage of 100 mV based on the standard hydrogen electrode was applied, this current value was 0.1 mA.
【００６１】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, in the case where 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 the overvoltage of 300 mV.
【００６２】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 so as to have a concentration of 1 M, in order to set the current flowing by electrolytic oxidation of methanol to 10 mA, an overvoltage of 550 mV is generated in the electrode using graphite supporting 1 wt% of platinum. Au (3
wt%) / TiO 2 powder was added to the electrode, which required an overvoltage of 450 mV.
【００６３】以上の結果から、Ａｕ（３ｗｔ％）／Ｔｉ
Ｏ2 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。 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。From the above results, Au (3 wt%) / Ti
It was clarified that the O 2 powder also has an excellent property of lowering the applied voltage as an electrode catalyst. Comparative Example 1 5.0 g of the same titanium oxide powder as that used in Example 1,
A 0.4 M aqueous solution of chloroauric acid (HAuCl 4 ) having a pH of 2 1
It was immersed in 0 ml, stirred, and left for 10 hours.
【００６４】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。Then, this was evaporated to dryness, and the mixture was calcined at 400 ° C. for 5 hours under air flow to obtain a catalyst Au (3.1 wt%) / TiO 2 (impregnation method) in which titanium oxide supported gold. . High-resolution transmission electron microscope observation revealed that the gold in this catalyst had a particle size of 300 Å or more.
【００６５】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。Then, using this catalyst, titanium oxide powder alone, and gold ultrafine particles alone having an average particle size of about 200 Å, the catalytic activity for the oxidation of hydrogen and carbon monoxide was measured under the same conditions as in Example 1. I just did
The results shown in Table 1 were obtained.
【００６６】 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。Table 1 Comparison of catalytic activity for oxidation reaction of hydrogen and carbon monoxide Catalyst activity 50% of hydrogen 50% of carbon monoxide Catalyst oxidation rate temperature Oxidation rate temperature Example 1 41 ° C.-35 ° C. Comparative example 1 210 ° C. 300 ° C. or higher * Titanium oxide 300 ° C. or higher * 300 ° C. or higher * Ultrafine gold particles 100 ° C. 295 ° C. *: Means that the oxidation rate did not reach 50% when measured up to a temperature of 300 ° C.
【００６７】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
方法で作製した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 shown in Table 1 show that even if a gold-supported catalyst is prepared by the most commonly used impregnation method, the gold ultrafine particle-immobilized titanium oxide-based oxide prepared by the method of the present invention has excellent properties. It shows that the low temperature catalytic activity is not expressed at all.
【００６８】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。Further, titanium oxide powder alone has almost no oxidation catalytic activity at temperatures of 300 ° C. or lower, and ultrafine gold particles alone have low oxidation catalytic activity. Considering that the oxidation of carbon proceeds at a lower temperature, in the gold ultrafine particle-immobilized titanium oxide Au (3 wt%) / TiO 2 of the present invention, due to the unique combined effect of gold ultrafine particles and titanium oxide, It is clear that extremely high oxidation catalytic activity is expressed and that the characteristic change that the oxidation of carbon monoxide proceeds at a lower temperature than the oxidation of hydrogen occurs.
【００６９】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。 実施例６ 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。The unique composite effect is exhibited in the Au (3 wt%) / TiO 2 catalyst of Example 1 in which the gold ultrafine particles are not spherical but hemispherical and titanium oxide is formed on the flat bottom surface. It is considered that this is because it has a characteristic structure of being bonded to the carrier. In contrast,
In the catalyst prepared by the impregnation method of Comparative Example 1, the gold had a nearly spherical shape, and the interaction with the titanium oxide support was weak,
Since the gold fine particles tend to agglomerate, the catalytic activity is poor. Example 6 In the same manner as in Example 1, two types of gold ultrafine particle-immobilized titanium oxides having different amounts of supported gold, namely Au (0.2
5 wt%) / TiO 2 and Au (2.4 wt%) / TiO
2 was produced.
【００７０】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
（Ｏ2 ）５容量％およびプロピレン（Ｃ3 Ｈ6 ）０．０
５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 titanium oxide with gold ultrafine particles immobilized thereon
0.1% by volume of nitric oxide (NO), 5% by volume of oxygen (O 2 ) and 0.0% of propylene (C 3 H 6 ).
100 ml of helium (He) mixed gas containing 5% by volume
The reaction was conducted at a flow rate of 1 / min to examine the activity of the reduction reaction of nitric oxide to nitrogen under the condition that oxygen was present in excess. For comparison, the activity of titanium oxide having no immobilized gold was also examined. FIG. 1 shows these results.
【００７１】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 ultrafine gold particle-immobilized titanium oxide, 26% of nitric oxide can be reduced to nitrogen at 350 ° C., and as the amount of supported gold increases, the temperature range in which the reduction performance is exhibited becomes. Since it spreads and the activity of titanium oxide in which gold is not immobilized is low, it has been clarified that high activity is exhibited for this reaction 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 composed of titanium oxide 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 Ｂ０１Ｄ 53/94 Ｂ０１Ｊ 23/52 ＺＡＢ Ａ 8017−4Ｇ Ｇ０１Ｎ 27/12 Ｃ 9218−2Ｊ Ｈ０１Ｍ 4/90 Ｍ Ｂ０１Ｄ 53/36 １０４ Ｚ ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Office reference number FI technical display location B01D 53/94 B01J 23/52 ZAB A 8017-4G G01N 27/12 C 9218-2J H01M 4/90 M B01D 53/36 104 Z
Claims (3)
るｐＨ７〜１１の液に、上記ｐＨ範囲を維持しつつ金化
合物水溶液を滴下した後、該金属酸化物を１００〜８０
０℃に加熱することを特徴とする金超微粒子固定化チタ
ン系酸化物の製造方法。1. A gold compound aqueous solution is added dropwise to a liquid having a pH of 7 to 11 containing a metal oxide containing titanium as a main component while maintaining the above pH range, and then the metal oxide is added to 100 to 80.
A method for producing a titanium-based oxide on which ultrafine gold particles are immobilized, which comprises heating to 0 ° C.
る金属酸化物を含有するｐＨ７〜１１の液に、上記ｐＨ
範囲を維持しつつ還元剤を滴下して金属酸化物表面に金
超微粒子を析出させることを特徴とする金超微粒子固定
化チタン系酸化物の製造方法。2. A liquid having a pH of 7 to 11 in which a gold compound is dissolved and a metal oxide containing titanium as a main component is added to the above-mentioned pH.
A method for producing a titanium-based oxide having ultrafine gold particles immobilized thereon, wherein a reducing agent is added dropwise while maintaining the range to precipitate ultrafine gold particles on the surface of the metal oxide.
る金属酸化物を含有するｐＨ１１以上の液に、二酸化炭
素ガスを吹き込むか、または酸性水溶液を滴下して、ｐ
Ｈ７〜１１とした後、該金属酸化物を１００〜８００℃
に加熱することを特徴とする金超微粒子固定化チタン系
酸化物の製造方法。3. Carbon dioxide gas is blown into a liquid containing a metal oxide containing titanium as a main component and containing titanium as a main component and having a pH of 11 or more, or an acidic aqueous solution is added dropwise to the p solution.
After setting H7 to 11, the metal oxide is heated to 100 to 800 ° C.
A method for producing a titanium-based oxide on which ultrafine gold particles are immobilized, characterized in that the titanium-based oxide is heated to a high temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4309705A JPH0753577B2 (en) | 1992-10-23 | 1992-10-23 | Method for producing titanium-based oxide with ultrafine gold particles immobilized |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4309705A JPH0753577B2 (en) | 1992-10-23 | 1992-10-23 | Method for producing titanium-based oxide with ultrafine gold particles immobilized |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0616422A JPH0616422A (en) | 1994-01-25 |
| JPH0753577B2 true JPH0753577B2 (en) | 1995-06-07 |
Family
ID=17996299
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4309705A Expired - Lifetime JPH0753577B2 (en) | 1992-10-23 | 1992-10-23 | Method for producing titanium-based oxide with ultrafine gold particles immobilized |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0753577B2 (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4411104A1 (en) * | 1994-03-30 | 1995-10-05 | Cerdec Ag | Process for the production of purple pigments |
| JP2615432B2 (en) * | 1994-10-28 | 1997-05-28 | 工業技術院長 | Method for partial oxidation of hydrocarbons with gold-titanium oxide containing catalyst |
| KR100715136B1 (en) * | 1999-04-08 | 2007-05-10 | 다우 글로벌 테크놀로지스 인크. | Method of preparing a catalyst containing gold and titanium |
| US6821923B1 (en) | 1999-04-08 | 2004-11-23 | Dow Global Technologies Inc. | Method of preparing a catalyst containing gold and titanium |
| 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 |
| US7829243B2 (en) | 2005-01-27 | 2010-11-09 | Applied Materials, Inc. | Method for plasma etching a chromium layer suitable for photomask fabrication |
| JP2008303131A (en) * | 2007-06-11 | 2008-12-18 | National Institute Of Advanced Industrial & Technology | Method for producing partially substituted type calcium titanate fine particle and material obtained by using the same |
| 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 |
| CN104988534B (en) * | 2015-05-29 | 2017-05-10 | 浙江工商大学 | Preparation method and application for Au and C co-doping visible-light response photocatalytic electrode |
| EP3456704A1 (en) * | 2017-09-19 | 2019-03-20 | Evonik Röhm GmbH | Catalyst for oxidative esterification of aldehydes to carboxylic acid esters |
| CN112091232A (en) * | 2020-09-11 | 2020-12-18 | 合肥工业大学 | Rapid preparation of Au-TiO under acidic condition2Method of composite construction |
-
1992
- 1992-10-23 JP JP4309705A patent/JPH0753577B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0616422A (en) | 1994-01-25 |
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