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 04:21
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.
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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) | 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 |