US4606798A
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Modified catalysts and process for the solar reduction of water
Assignee: Commonwealth Scientific and Industrial Research Organisation
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Filing: 1985-04-23
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Granted: 1986-08-19
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Expires: 2005-04-23
Abstract
Abstract A solar reaction system which produces hydrogen by reduction of hydronium ions using methylviologen or a related compound as an electron-transfer agent and a platinum electron-transfer catalyst, wherein the catalyst is modified with a water-soluble divalent sulphur compound, or a sulphur compound in which the sulphur is reducible to the divalent state, in an amount sufficient to inhibit hydrogenation side-reactions during the solar reduction process but not sufficient to significantly suppress the reduction of hydronium ion to hydrogen by the electron-transfer agent.
Inventors
- 👤 Wolfgang H. F. Sasse
- 👤 Oddvar Johansen
- 👤 Albert W. Mau
- 👤 Jean D. Swift
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:19
CPC Classifications
B; B01; B01J; B01J19/00; B01J19/08; B01J19/12; B01J19/122; B01J19/127; C; C01; C01B; C01B3/00; C01B3/02; C01B3/04; C01B3/042; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/36
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
158 words
A photochemical reaction system which produces hydrogen by reduction of hydronium ions using methylviologen or a related compound as an electrontransfer agent and a platinum electron-transfer catalyst, wherein the catalyst is modified with a sulfur compound which the sulphur is reducible to the divalent state, said sulphur compound being a sulphine, sulphoxide or other oxy-sulphur compound capable of being reduced by hydrogen on platnium to a compound selected from the group consisting of a thiocyanate salt; a thiosulphate salt; a thiosulphide salt; a cyclic or open chain thiol; a cyclic or open chain thiocarbonyl compound; a sulphur containing amino acid or polypeptide; and a heterocyclic compound containing formally divalent sulphur in an amount sufficent to inhibit hydrogenation side-reactions during the reduction process but not sufficient to significantly suppress the reduction of hydronium ion to hydrogen by the electron-transfer agent, the amount of the sulphur compound used being from 0.5 to 100 moles per mole of the patinum catalyst.
Claim 2
Dependent Claim
158 words
A photochemical reaction system which produces hydrogen by reduction of hydronium ions using methylviologen or a related compound as an electrontransfer agent and a platinum electron-transfer catalyst, wherein the catalyst is modified with a sulfur compound which the sulphur is reducible to the divalent state, said sulphur compound being a sulphine, sulphoxide or other oxy-sulphur compound capable of being reduced by hydrogen on platnium to a compound selected from the group consisting of a thiocyanate salt; a thiosulphate salt; a thiosulphide salt; a cyclic or open chain thiol; a cyclic or open chain thiocarbonyl compound; a sulphur containing amino acid or polypeptide; and a heterocyclic compound containing formally divalent sulphur in an amount sufficent to inhibit hydrogenation side-reactions during the reduction process but not sufficient to significantly suppress the reduction of hydronium ion to hydrogen by the electron-transfer agent, the amount of the sulphur compound used being from 0.5 to 100 moles per mole of the patinum catalyst.
Claim 3
Dependent Claim
22 words
A system as claimed in claim 1, wherein the electron-transfer agent is the 1,1'-dimethyl-4,4'-bipyrodonim dication, the 1,1',2,2'-tetramethyl-4,4'-bipyridinium dication or the 1,1',2,2',6,6'-hexamethyl-4,4'-bipyridinium dication.
Claim 4
Dependent Claim
17 words
A system as claimed in claim 1, wherein the photochemical reaction is the solar reduction of water.
Claim 5
Dependent Claim
162 words
A platinum for use in a photochemical reaction system which produces hydrogen by reduction of hydronium ions using methylviologen or a related compound as an electron-transfer agent and a platinum electron-transfer catalyst, wherein the catalyst is modified with a sulphur compound in which the sulphur is reducible to the divalent state, said sulphur compound being a sulphone, sulphoxide or other oxy-sulphur compound capable of being reduced by hydrogen or platinum to a compound selected from the group consisting of a thiocyanate salt; a thiosulphate salt; a thiosulphide salt; a cyclic or open chain thiol; a cyclic or open chain thiocarbonyl compound; a sulphur containing amino-acid or polypeptide; and a heterocyclic compound containing formally divalent sulphur in an amount sufficent to inhibit hydrogenation side-reactions during the reduction process but not sufficient to suppress the reduction of hydronium ion to hydrogen by the electron-transfer agent, the amount if the sulphur compound present being from 0.5 to 100 moles per mole of the platinum catalyst.
Claim 6
Dependent Claim
162 words
A platinum for use in a photochemical reaction system which produces hydrogen by reduction of hydronium ions using methylviologen or a related compound as an electron-transfer agent and a platinum electron-transfer catalyst, wherein the catalyst is modified with a sulphur compound in which the sulphur is reducible to the divalent state, said sulphur compound being a sulphone, sulphoxide or other oxy-sulphur compound capable of being reduced by hydrogen or platinum to a compound selected from the group consisting of a thiocyanate salt; a thiosulphate salt; a thiosulphide salt; a cyclic or open chain thiol; a cyclic or open chain thiocarbonyl compound; a sulphur containing amino-acid or polypeptide; and a heterocyclic compound containing formally divalent sulphur in an amount sufficent to inhibit hydrogenation side-reactions during the reduction process but not sufficient to suppress the reduction of hydronium ion to hydrogen by the electron-transfer agent, the amount if the sulphur compound present being from 0.5 to 100 moles per mole of the platinum catalyst.
Claim 7
Dependent Claim
154 words
A process for reduction of water using methylviologen or a related compound as an electron-transfer agent and a platinum electron transfer catalyst, wherein the catalyst is modified with a sulphur compound in which the sulphur is reducible to the divalent state, said sulphur compound being a sulphone, sulphoxide or other oxy-sulphur compound capable of being reduced by hydrogen on platinum to a compound selected from the group consisting of a thiocyanate salt; a thiosulphate salt; a thiosulphide salt; a cyclic or open chain thiol; a cyclic or open chain thiocarbonyl compound; a sulphur containing amino-acid or polypeptide; and a heterocyclic compound containing formally divalent sulphur in an amount sufficent to inhibit hydrogenation side-reactions during the solar reduction process but not sufficient to suppress the reduction of hydronium ion to the hydrogen by the electron-transfer agent, the amount of the sulphur compound used being from 0.5 to 100 moles per mole of the platinum catalyst.
Claim 8
Dependent Claim
154 words
A process for reduction of water using methylviologen or a related compound as an electron-transfer agent and a platinum electron transfer catalyst, wherein the catalyst is modified with a sulphur compound in which the sulphur is reducible to the divalent state, said sulphur compound being a sulphone, sulphoxide or other oxy-sulphur compound capable of being reduced by hydrogen on platinum to a compound selected from the group consisting of a thiocyanate salt; a thiosulphate salt; a thiosulphide salt; a cyclic or open chain thiol; a cyclic or open chain thiocarbonyl compound; a sulphur containing amino-acid or polypeptide; and a heterocyclic compound containing formally divalent sulphur in an amount sufficent to inhibit hydrogenation side-reactions during the solar reduction process but not sufficient to suppress the reduction of hydronium ion to the hydrogen by the electron-transfer agent, the amount of the sulphur compound used being from 0.5 to 100 moles per mole of the platinum catalyst.
Claim 9
Dependent Claim
22 words
A process as claimed in claim 5, wherein the electron-transfer agents is the 1,1'-diemthyl-4,4'-bipyridinium dication, the 1,1',2,2'-tetramethyl-4,4'-bipyridinium dication or the 1,1',2,2',6,6'-hexamethyl-4,4'-bipyridinium dication.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |