Patent US5250487A successfully refreshed from Google Patents.
US5250487A
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Carrier catalyst, process for its preparation, and its use for the preparation of vinyl acetate
Assignee: Hoechst AG
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Filing: 1992-06-18
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Granted: 1993-10-05
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Expires: 2012-06-18
Abstract
Abstract The invention relates to a process for the preparation of a catalyst which contains palladium and/or compounds thereof and alkali metal compounds, and additionally cadmium compounds and/or gold and/or compounds thereof, on support particles which have been pressed from SiO 2 or an iO 2 -Al 2 O 3 mixture with the aid of a binder which comprises a) washing the roasted support particles with an acid which does not react with SiO 2 or SiO 2 -Al 2 O 3 mixtures, until no further cations of the binder employed during pressing of the support particles are released from the support particles; b) then impregnating the support particles with palladium, and gold or cadmium; c) then bringing the impregnated support particles into contact with a solution of a base at least until the thickness of the nobel metal shell generated in this way on the support particles no longer changes substantially; and d) then impregnating the support particles with an alkali metal compound. A shell-like distribution of the palladium and if appropriate of the gold in the support particles is generated in this manner. Furthermore, the invention relates to a catalyst prepared in this way and to its use for the preparation of vinyl acetate.
Inventors
- 👤 Peter Wirtz
- 👤 Karl-Fred Worner
- 👤 Friedrich Wunder
- 👤 Klaus Fichler
- 👤 Gunter Roscher
- 👤 Ioan Nicolau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:38
CPC Classifications
B; B01; B01J; B01J31/00; B01J37/00; B01J37/02; B01J37/0201; B01J37/0205; B01J23/00; B01J23/38; B01J23/54; B01J23/56; B01J23/58; B01J23/60; C; C07; C07C; C07C67/00; C07C67/04; C07C67/05; C07C67/055
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
188 words
A process for the preparation of a catalyst which contains palladium and/or compounds thereof and alkali metal compounds, and additionally cadmium compounds and/or gold and/or compounds thereof, on support particles which ave been pressed from SiO 2 or an SiO 2 -Al 2 O 3 mixture with the aid of a binder comprising one or more Li, Mg, Al, Zn, Fe or Mn salts of a C 2 -C 26 -carboxylic acid and have subsequently been roasted in oxygen-containing gases which comprises a) washing the roasted support particles with an acid which does not react with SiO 2 or SiO 2 -Al 2 O 3 mixtures, until no further cations of the binder employed during pressing of the support particles are released from the support particles; b) impregnating the support particles with palladium, and optionally gold or cadmium or mixtures thereof; c) bringing the impregnated support particles into contact with a solution of a base at least until the thickness of the noble metal shell generated in this way on the support particles no longer changes substantially; and d) impregnating the support particles with an alkali metal compound.
Claim 2
Dependent Claim
188 words
A process for the preparation of a catalyst which contains palladium and/or compounds thereof and alkali metal compounds, and additionally cadmium compounds and/or gold and/or compounds thereof, on support particles which ave been pressed from SiO 2 or an SiO 2 -Al 2 O 3 mixture with the aid of a binder comprising one or more Li, Mg, Al, Zn, Fe or Mn salts of a C 2 -C 26 -carboxylic acid and have subsequently been roasted in oxygen-containing gases which comprises a) washing the roasted support particles with an acid which does not react with SiO 2 or SiO 2 -Al 2 O 3 mixtures, until no further cations of the binder employed during pressing of the support particles are released from the support particles; b) impregnating the support particles with palladium, and optionally gold or cadmium or mixtures thereof; c) bringing the impregnated support particles into contact with a solution of a base at least until the thickness of the noble metal shell generated in this way on the support particles no longer changes substantially; and d) impregnating the support particles with an alkali metal compound.
Claim 3
Dependent Claim
25 words
The process as claimed in claim 1, wherein hydrochloric acid, sulfuric acid, phosphoric acid or nitric acid is used as the acid in step a).
Claim 4
Dependent Claim
18 words
The process as claimed in claim 1, wherein hydrochloric acid is used as the acid in step a).
Claim 5
Dependent Claim
20 words
The process as claimed in claim 1, wherein an alkali metal hydroxide is used as the base in step c).
Claim 6
Dependent Claim
16 words
The process as claimed in claim 1, wherein a potassium compound is employed in step d).
Claim 7
Dependent Claim
27 words
The process as claimed in claim 1, wherein the palladium content is from 0.5 to 2.5% by weight, based on the total weight of the supported catalyst.
Claim 8
Dependent Claim
27 words
The process as claimed in claim 1, wherein the palladium content is from 1.0 to 1.6% by weight, based on the total weight of the supported catalyst.
Claim 9
Dependent Claim
27 words
The process as claimed in claim 1, wherein the content of gold is 0.2 to 0.7% by weight based on the total weight of the support catalyst.
Claim 10
Dependent Claim
24 words
The process as claimed in claim 1, wherein cadmium content is 0.5 to 5% by weight, based on the total weight of the catalyst.
Claim 11
Dependent Claim
26 words
The process as claimed in claim 1, wherein alkaline metal compound content is 0.5 to 5% by weight, based on the total weight of the catalyst.
Claim 12
Dependent Claim
11 words
A catalyst made by the process as claimed in claim 1.
Claim 13
Dependent Claim
11 words
A catalyst made from the process as claimed in claim 2.
Claim 14
Dependent Claim
12 words
A catalyst as made in the process as claimed in claim 4.
Claim 15
Dependent Claim
12 words
A catalyst as made by the process as claimed in claim 5.
Claim 16
Dependent Claim
64 words
The catalyst as claimed in claim 11, wherein the catalyst has a surface area of 50 to 250 m 2 /g and a pore volume of 0.4-1.2 ml/g at a particle size of 5-7 mm, 5-20% of the pore volume being formed by pores having a radius of 200-3000Å and 50-90% of the pore volume being formed by pores having a radius of 70-100Å.
References Cited (Backward Citations)
DE1249255B
Cited
GB1117595A
Cited
US3775342A
Cited
US3939199A
Cited
US4668819A
Cited
US4048096A
Cited
EP0004079A2
Cited
EP0330853A2
Cited
US4902823A
Cited
CA2018991A1
Cited
DE3919524A1
Cited
EP0403950A1
Cited
CA2031429A1
Cited
EP0431478A2
Cited
EP0464633B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-10-04 | 1997-04-05 | 1997-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-04 | 2001-04-05 | 2001-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-04 | 2005-04-05 | 2005-10-05 | $7700.00 | Window Closed / Lapsed |