US3932309A
Expired / Lapsed
US
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Auto exhaust catalysts prepared from sulfite treated platinum and palladium salt solutions
Assignee: WR Grace and Co Conn
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Filing: 1974-06-05
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Granted: 1976-01-13
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Expires: 1994-06-05
Abstract
Abstract A process for preparing a catalyst that has improved activity and efficiency for conversion of hydrocarbons is disclosed. The catalyst is prepared by applying sulfito complexes have the emperical formula M6(x) (SO3)4 where M is H+ NA+, K+ or NH4+ and x is platinum, palladium or mixtures thereof. In addition, the compounds M2(x) (SO3)2 and M2(x) (SO3)2 also have utility in our process. The complex salt is impregnated onto a support and activated by calcination in air or heating in a reducing atmosphere.
Inventors
- 👤 James Richard Graham
- 👤 Michael Vance Ernest
- 👤 James Michael Maselli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:36
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/54; B01J23/56; B01J23/63; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
138 words
A process for preparing an auto exhaust conversion catalyst characterized by substantially improved conversion of carbon monoxide and hydrocarbons consisting essentially of the following steps: a. preparing a solution from a platinum, palladium or platinum-palladium complex salt having the formula M 6 (X) (SO 3 ) 4 or M 2 (X) (SO 3 ) 2 wherein M is Na+, NH 4 + or H+ and X is platinum, palladium or a mixture of platinum and palladium, b. impregnating a base selected from the group consisting of alumina, silica-alumina, mullite, cordierite and zirconia with said solution, c. drying and activating by heating in air at a temperature of 800° to 1400°F. for 1 to 4 hours or in a reducing environment at a temperature of 600° to 800°F. for 0.5 to 2 hours, and d. recovering the catalyst product.
Claim 2
Dependent Claim
138 words
A process for preparing an auto exhaust conversion catalyst characterized by substantially improved conversion of carbon monoxide and hydrocarbons consisting essentially of the following steps: a. preparing a solution from a platinum, palladium or platinum-palladium complex salt having the formula M 6 (X) (SO 3 ) 4 or M 2 (X) (SO 3 ) 2 wherein M is Na+, NH 4 + or H+ and X is platinum, palladium or a mixture of platinum and palladium, b. impregnating a base selected from the group consisting of alumina, silica-alumina, mullite, cordierite and zirconia with said solution, c. drying and activating by heating in air at a temperature of 800° to 1400°F. for 1 to 4 hours or in a reducing environment at a temperature of 600° to 800°F. for 0.5 to 2 hours, and d. recovering the catalyst product.
Claim 3
Dependent Claim
21 words
The process according to claim 1 wherein the base is alumina stabilized by the addition of about 5 weight percent ceria.
Claim 4
Dependent Claim
40 words
The process according to claim 1 wherein the platinum, palladium or mixture of platinum-palladium sulfito complex salts are prepared by treating solutions of chloroplatinic acid, palladium nitrate or mixtures thereof with sodium bisulfite followed by precipitating, washing and drying steps.
Claim 5
Dependent Claim
40 words
The process according to claim 1 wherein the platinum, palladium or mixture of platinum-palladium sulfito complex salts are prepared by treating solutions of chloroplatinic acid, palladium nitrate or mixtures thereof with ammonium bisulfite followed by precipitating, washing and drying steps.
Claim 6
Dependent Claim
30 words
The process according to claim 1 wherein the platinum-palladium sulfito complex salts are prepared by treating solutioins of a mixture of chloroplatinic acid and palladium nitrate with gaseous sulfur dioxide.
Claim 7
Dependent Claim
28 words
The process according to claim 1 wherein the platinum and palladium content can vary from Pt 0 .99 Pd 0 .01 to Pt 0 .01 Pd 0 .99.
References Cited (Backward Citations)
US3636029A
Cited
US3803054A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-12 | 1979-07-14 | 1980-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-12 | 1983-07-14 | 1984-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-12 | 1987-07-14 | 1988-01-13 | $7700.00 | Window Closed / Lapsed |