Patent US4394293A successfully refreshed from Google Patents.
US4394293A
Expired / Lapsed
US
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Catalyst for the photolytic production of hydrogen from water
Assignee: PHIBRO-SALOMON Inc
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Filing: 1980-09-05
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Granted: 1983-07-19
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Expires: 2000-09-05
Abstract
Abstract A catalytic dispersion of fine metal particles mediates the photodissociation of water into hyrogen gas. A protective agent adsorptive to said particles and selected from among homopolymers, copolymers, hydrocarbyl radicals and polysaccharides stabilizes the said dispersion.
Inventors
- 👤 Michael Gratzel
- 👤 John Kiwi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:47
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; C; C01; C01B; C01B3/00; C01B3/02; C01B3/04; C01B3/042; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/36
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
47 words
A stabilized catalyst for promoting electron transfer to water protons for mediating evolution of hydrogen gas by photolysis comprising an active catalytic reducing amount of Noble metal particles in finely divided form and a water permeable protective agent adsorptive to said metal particles and being polyvinyl alcohol.
Claim 2
Dependent Claim
47 words
A stabilized catalyst for promoting electron transfer to water protons for mediating evolution of hydrogen gas by photolysis comprising an active catalytic reducing amount of Noble metal particles in finely divided form and a water permeable protective agent adsorptive to said metal particles and being polyvinyl alcohol.
Claim 3
Dependent Claim
27 words
The catalyst of claim 1 wherein the Noble metal is selected from the group consisting of platinum, palladium, rhodium, ruthenium, iridium, osmium, silver, gold and mixtures thereof.
Claim 4
Dependent Claim
16 words
The catalyst of claim 1 wherein the Noble metal is platinum, palladium or a mixture thereof.
Claim 5
Dependent Claim
11 words
The catalyst of claim 1 where the Noble metal is platinum.
Claim 6
Dependent Claim
64 words
A method for preparing the catalyst of claim 1 having a particle size not greater than 500 A diameter said method comprising (1) adding one or more reducible Noble metal compounds to an aqueous medium, (2) reducing said Noble metal compounds in the presence of polyvinyl alcohol and (3) separating from the resultant mixtures particles larger than 500 A diameter to obtain said catalyst.
Claim 7
Dependent Claim
17 words
The method of claim 5 wherein the separation of step 3 is achieved by centrifugation or ultra-filtration.
Claim 8
Dependent Claim
32 words
The method of claim 5 wherein the separation of step 3 is achieved by centrifugation at at least about 20,000 r.p.m. conducted over a period of not less than about 2 hours.
Claim 9
Dependent Claim
28 words
The method of claim 5 wherein the Noble metal compound is selected from the group consisting of platinum, palladium, rhodium, ruthenium, iridium, osmium, silver, gold or mixtures thereof.
Claim 10
Dependent Claim
17 words
The method of claim 5 wherein the Noble metal compound is platinum, palladium or a mixture thereof.
Claim 11
Dependent Claim
12 words
The method of claim 5 wherein the Noble metal compound is platinum.
Claim 12
Dependent Claim
13 words
The method of claim 10 wherein the reducible metal compound is chloroplatinic acid.
Claim 13
Dependent Claim
15 words
The method of claim 5 wherein the particle size is not greater than 250 A.
References Cited (Backward Citations)
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US4292197A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-18 | 1987-01-17 | 1987-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-18 | 1991-01-17 | 1991-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-18 | 1995-01-17 | 1995-07-19 | $7700.00 | Window Closed / Lapsed |