US4342667A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing a silver catalyst
Assignee: Scientific Design LLC
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Filing: 1979-03-26
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Granted: 1982-08-03
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Expires: 1999-03-26
Abstract
Abstract A supported silver catalyst for oxidation of ethylene to ethylene oxide is prepared by impregnation of the support, activation, and solvent washing, with each step being carried out at a relatively low temperature. Silver so deposited has an average particle diameter of about 0.5-0.7 microns and is capable of being promoted by post-deposition of alkali metals such as cesium, rubidium, and potassium.
Inventors
- 👤 William D. Armstrong
- 👤 Charles N. Winnick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:55
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/54; B01J23/66; C; C07; C07D; C07D301/00; C07D301/02; C07D301/03; C07D301/04; C07D301/08; C07D301/10; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
187 words
A process for preparing a catalyst useful in the oxidation by molecular oxygen of ethylene to ethylene oxide comprising: (a) impregnating a support with a solution of a silver salt selected from the group consisting of silver acetate, silver benzoate, silver oxalate, silver lactate, silver malonate, silver succinate, silver glutarate, and silver maleate and comprising at least one non-nitrogenous reducing agent selected from the group consisting of alcohols, polyols, and keto alcohols at a temperature at or below 110° C.; (b) activating and drying said impregnated support of (a) at a temperature not below 85° C. or in excess of 200° C. for a sufficient time to permit substantially all of the silver in the impregnated solution to be deposited on said support and leaving decomposable residues on said support; (c) removing at least 85% of said residues of (b) from said activated support (b) by washing said support with a solvent; (d) thereafter post-impregnating the catalyst of (c) with a solution of a compound of one or more alkali metals selected from the group consisting of cesium, rubidium, and potassium and thereafter drying said post-impregnated catalyst.
Claim 2
Dependent Claim
187 words
A process for preparing a catalyst useful in the oxidation by molecular oxygen of ethylene to ethylene oxide comprising: (a) impregnating a support with a solution of a silver salt selected from the group consisting of silver acetate, silver benzoate, silver oxalate, silver lactate, silver malonate, silver succinate, silver glutarate, and silver maleate and comprising at least one non-nitrogenous reducing agent selected from the group consisting of alcohols, polyols, and keto alcohols at a temperature at or below 110° C.; (b) activating and drying said impregnated support of (a) at a temperature not below 85° C. or in excess of 200° C. for a sufficient time to permit substantially all of the silver in the impregnated solution to be deposited on said support and leaving decomposable residues on said support; (c) removing at least 85% of said residues of (b) from said activated support (b) by washing said support with a solvent; (d) thereafter post-impregnating the catalyst of (c) with a solution of a compound of one or more alkali metals selected from the group consisting of cesium, rubidium, and potassium and thereafter drying said post-impregnated catalyst.
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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) | 1985-08-02 | 1986-02-01 | 1986-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-02 | 1990-02-01 | 1990-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-02 | 1994-02-01 | 1994-08-03 | $7700.00 | Window Closed / Lapsed |