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US4379756A
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Reactivation of supported catalysts which contain palladium, copper and tellurium
Assignee: BASF SE
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Filing: 1981-05-06
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Granted: 1983-04-12
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Expires: 2001-05-06
Abstract
Abstract A process for reactivating supported catalysts which contain palladium, copper and tellurium and which are used for the acyloxylation of unsubstituted or substituted butadiene to give butenediol esters, wherein the supported catalysts are heated at from 200° to 900° C. in the presence of a gas which is inert under these treatment conditions.
Inventors
- 👤 Hans-Martin Weitz
- 👤 Rolf Fischer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:57
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/90; B01J23/96; B01J27/00; B01J27/28; B01J27/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
77 words
In a process for reactivating a supported catalyst which contains palladium, copper and tellurium and which has been used for the acyloxylation of unsubstituted or substituted butadiene to give butenediol esters, the improvement which comprises: heating the used catalyst at from 200° to 900° C. under an essentially inert gas atmosphere, free of a reducing agent, for a period of time sufficient at said temperature to reactivate the catalyst while free of contact with any reactive gas.
Claim 2
Dependent Claim
77 words
In a process for reactivating a supported catalyst which contains palladium, copper and tellurium and which has been used for the acyloxylation of unsubstituted or substituted butadiene to give butenediol esters, the improvement which comprises: heating the used catalyst at from 200° to 900° C. under an essentially inert gas atmosphere, free of a reducing agent, for a period of time sufficient at said temperature to reactivate the catalyst while free of contact with any reactive gas.
Claim 3
Dependent Claim
26 words
A process as claimed in claim 1 wherein the reactivation by heating under an inert gas atmosphere is carried out at from 600° to 800° C.
Claim 4
Dependent Claim
23 words
A process as claimed in claim 1 wherein the inert atmosphere is a gas selected from the group consisting of nitrogen and argon.
Claim 5
Dependent Claim
31 words
A process as claimed in claim 1 which contains from 1 to 10% palladium, from 0.1 to 30% copper and from 0.01 to 10% tellurium, based on the weight of catalyst.
Claim 6
Dependent Claim
48 words
A process as claimed in claim 4 wherein the catalyst contains from 0.01 to 6 gram atoms of copper and from 0.01 to 0.4 gram atom of tellurium per gram atom of palladium and wherein the active catalyst contains intermetallic phases having the composition PdCu 3 or PdCu.
Claim 7
Dependent Claim
34 words
A process as claimed in claim 5 wherein the catalytically active metals are applied to a carrier in an amount of 0.01 to 30% by weight, based on the total weight of supported catalyst.
Claim 8
Dependent Claim
23 words
A process as claimed in claim 5 wherein the reactivation under an inert gas atmosphere is carried out at 600° to 800° C.
Claim 9
Dependent Claim
32 words
A process as claimed in claim 1 wherein the catalyst to be reactivated is pretreated with a carboxylic acid solvent in a separate step prior to heating under said inert gas atmosphere.
Claim 10
Dependent Claim
51 words
A process as claimed in claim 7 wherein the solvent pretreatment is carried out for about 0.5 to 12 hours at from 20° to 200° C., and the catalyst is then dried at from 50° to 200° C. under said inert gas atmosphere prior to said heating at a higher temperature.
Claim 11
Dependent Claim
24 words
A process as claimed in claim 8 wherein the dry catalyst is heated under an inert gas atmosphere for about 0.5 to 10 hours.
References Cited (Backward Citations)
US3578608A
Cited
DE2943407A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-11 | 1986-10-11 | 1987-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-11 | 1990-10-11 | 1991-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-11 | 1994-10-11 | 1995-04-12 | $7700.00 | Window Closed / Lapsed |