US4839327A
Expired / Lapsed
US
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Method for the production of ultra-fine gold particles immobilized on a metal oxide
Assignee: MINISTRY OF INTERNATIONAL TRADE
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Filing: 1988-03-22
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Granted: 1989-06-13
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Expires: 2008-03-22
Abstract
Abstract A composite having ultra-fine gold particles uniformly and strongly immobilized in a deposited state on a metal oxide is obtained by preparing a solution containing the metal oxide as a carrier and a gold compound, adjusting the pH value of the solution to a specific level thereby inducing precipitation and deposition of gold hydroxide or gold on the carrier and, when the precipitate is in the form of gold hydroxide, further, firing the precipitate. The ultra-fine gold particles immobilized on metal oxides are useful as a catalyst for reduction and oxidation, in sensor elements for flammable gases, and as an electrode catalyst.
Inventors
- 👤 Masatake Haruta
- 👤 Tetsuhiko Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:22
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; B; B01; B01J; B01J23/00; B01J23/38; B01J23/48; B01J23/52; B01J23/54; B01J23/66; B01J23/68; B01J23/70; B01J23/89; C04B41/45; C04B41/4584; C04B41/80; C04B41/81; H; H01; H01M; H01M4/00; H01M4/86; H01M4/90; H01M2004/8678; H01M2004/8684; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
91 words
A method for the production of ultra-fine gold particles immobilized on a metal oxide, characterized by adding dropwise an aqueous gold compound solution kept at a pH value of 7 to 11 to a metal oxide-containing water similarly kept at a pH value of 7 to 11 thereby obtaining an aqueous solution of said metal oxide having gold hydroxide immobilized thereon, separating said metal oxide having gold hydroxide immobilized thereon from said aqueous solution, and heating the separated metal oxide at a temperature in the range of 100° to 800° C.
Claim 2
Independent Claim
91 words
A method for the production of ultra-fine gold particles immobilized on a metal oxide, characterized by adding dropwise an aqueous gold compound solution kept at a pH value of 7 to 11 to a metal oxide-containing water similarly kept at a pH value of 7 to 11 thereby obtaining an aqueous solution of said metal oxide having gold hydroxide immobilized thereon, separating said metal oxide having gold hydroxide immobilized thereon from said aqueous solution, and heating the separated metal oxide at a temperature in the range of 100° to 800° C.
Claim 3
Dependent Claim
65 words
The method according to claim 1, wherein said metal oxide is at least one member selected from the group consisting of MnO 2 , Fe 2 O 3 , Co 3 O 4 , NiO, CuO, CuMnO 2 , Co--Mn complex oxide, Al 2 O 3 , SiO 2 , TiO 2 , V 2 O 5 , MoO 3 , and WO 3 .
Claim 4
Dependent Claim
52 words
The method according to claim 1, wherein said gold compound is at least one member selected from the group consisting of chloroauric acid (HAuCl 4 ), sodium chloroaurate (NaAuCl 4 ), gold cyanide (AuCN), potassium cyanoaurate {K[Au(CN) 2 ]}, and trichlorodiethylamino auric acid [(C 2 H 5 ) 2 NH.AuCl 3 ].
Claim 5
Dependent Claim
28 words
The method according to claim 1, wherein the amount of said metal oxide in said aqueous metal oxide solution is in the range of 10 to 200 g/lit.
Claim 6
Dependent Claim
32 words
The method according to claim 1, wherein the amount of said gold compound in said aqueous gold compound solution for dropwise adding is in the range of 0.1 mol/lit to 0.001 mol/lit.
Claim 7
Dependent Claim
29 words
The method according to claim 1, wherein the temperature of the water containing said metal oxide carrying thereon gold hydroxide is in the range of 20° to 80° C.
Claim 8
Independent Claim
85 words
A method for the production of ultra-fine gold particles immobilized on a metal oxide surface, characterized by adding a reducing agent adapted to induce precipitation of gold and kept at a pH value of 7 to 11 to an aqueous metal oxide-containing solution having a gold compound dissolved therein and kept at a pH value of 7 to 11 thereby obtaining an aqueous solution of said metal oxide having gold immobilized thereon, and separating said metal oxide having gold immobilized thereon from said aqueous solution.
Claim 9
Independent Claim
85 words
A method for the production of ultra-fine gold particles immobilized on a metal oxide surface, characterized by adding a reducing agent adapted to induce precipitation of gold and kept at a pH value of 7 to 11 to an aqueous metal oxide-containing solution having a gold compound dissolved therein and kept at a pH value of 7 to 11 thereby obtaining an aqueous solution of said metal oxide having gold immobilized thereon, and separating said metal oxide having gold immobilized thereon from said aqueous solution.
Claim 10
Dependent Claim
36 words
The method according to claim 7, wherein the concentration of said gold compound in said aqueous metal oxide solution having said gold compound dissolved therein is in the range of 1×10 -2 to 1×10 -5 mol/liter.
Claim 11
Dependent Claim
24 words
The method according to claim 7, wherein said reducing agent is one member selected from the group consisting of hydrazine, formalin, and sodium citrate.
Claim 12
Dependent Claim
29 words
The method according to claim 7, wherein the temperature of said aqueous metal oxide solution having said gold compound dissolved therein is in the range 0° to 80° C.
Claim 13
Dependent Claim
32 words
The method according to claim 7, wherein the amount of said reducing agent is in the range of about 1.5 to about 10 times the amount stoichiometrically required for precipitation of gold.
Claim 14
Independent Claim
129 words
A method for the production of ultra-fine gold particles immobilized on a metal oxide, characterized by adding one member selected from the group consisting of carbon dioxide gas and acidic aqueous solutions to an aqueous metal oxide solution having a gold compound dissolved therein and kept at a pH value of not less than 11 thereby adjusting the pH value of said aqueous solution in the range of 7 to 11 and obtaining an aqueous solution of said metal oxide having gold hydroxide deposited on the surface thereof, separating the metal oxide having gold hydroxide deposited thereon from said aqueous solution, and after washing then heating the separated metal oxide having gold hydroxide deposit on the surface thereof at a temperature in the range of 100° to 800° C.
Claim 15
Independent Claim
129 words
A method for the production of ultra-fine gold particles immobilized on a metal oxide, characterized by adding one member selected from the group consisting of carbon dioxide gas and acidic aqueous solutions to an aqueous metal oxide solution having a gold compound dissolved therein and kept at a pH value of not less than 11 thereby adjusting the pH value of said aqueous solution in the range of 7 to 11 and obtaining an aqueous solution of said metal oxide having gold hydroxide deposited on the surface thereof, separating the metal oxide having gold hydroxide deposited thereon from said aqueous solution, and after washing then heating the separated metal oxide having gold hydroxide deposit on the surface thereof at a temperature in the range of 100° to 800° C.
Claim 16
Dependent Claim
65 words
The method according to claim 12, wherein said metal oxide is at least one member selected from the group consisting of MnO 2 , Fe 2 O 3 , Co 3 O 4 , NiO, CuO, CuMnO 2 , Co--Mn complex oxide, Al 2 O 3 , SiO 2 , TiO 2 , V 2 O 5 , MoO 3 , and WO 3 .
Claim 17
Dependent Claim
52 words
The method according to claim 12, wherein said gold compound is at least one member selected from the group consisting of chloroauric acid (HAuCl 4 ), sodium chloroaurate (NaAuCl 4 ), gold cyanide (AuCN), potassium cyanoaurate K[Au(CN) 2 ], and trichlorodiethylamine auric acid [(C 2 H 5 ) 2 NH.AuCl 3 ].
Claim 18
Dependent Claim
30 words
The method according to claim 12, wherein the temperature of said aqueous metal oxide solution having said gold compound dissolved therein is in the range of 0° to 80° C.
Claim 19
Dependent Claim
32 words
The method according to claim 12, wherein said acidic aqueous solution is one member selected from the group consisting of aqueous solutions of nitric acid, hydrochloric acid, sulfuric acid, and acetic acid.
References Cited (Backward Citations)
GB1472062A
Cited
US4698324A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |