US4379778A
Expired / Lapsed
US
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Hydrogen peroxide synthesis
Assignee: Air Products and Chemicals Inc
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Filing: 1980-10-10
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Granted: 1983-04-12
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Expires: 2000-10-10
Abstract
Abstract This invention relates to improvements in palladium-carbon catalysts for the production of hydrogen peroxide from a mixture of hydrogen and oxygen in the presence of an aqueous liquid capable of inhibiting the decomposition of hydrogen peroxide. The improvement comprises pretreating the catalyst with an aldehyde or ketone, and, preferably, also pretreating the catalyst with a dilute solution of hydrochloric acid. Improved catalysts are obtained by reducing a soluble palladium compound deposited on a high surface area non-graphitic carbon base, in the form of a dried powder, with hydrogen at 27°-200° C.
Inventors
- 👤 Augustine I. Dalton, Jr.
- 👤 Ronald W. Skinner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:13
CPC Classifications
C; C01; C01B; C01B15/00; C01B15/01; C01B15/029
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
75 words
In a process for producing hydrogen peroxide by contacting a mixture of hydrogen and oxygen with a previously-reduced palladium catalyst supported on a carbon base in the presence of an aqueous liquid, containing an acid and a non-acidic oxygen-containing organic compound, capable of inhibiting the decomposition of the thus-produced hydrogen peroxide, the improvement comprising pretreating the catalyst with a ketone or aldehyde before contacting the thus-pretreated catalyst with hydrogen and oxygen in the aqueous medium.
Claim 2
Dependent Claim
75 words
In a process for producing hydrogen peroxide by contacting a mixture of hydrogen and oxygen with a previously-reduced palladium catalyst supported on a carbon base in the presence of an aqueous liquid, containing an acid and a non-acidic oxygen-containing organic compound, capable of inhibiting the decomposition of the thus-produced hydrogen peroxide, the improvement comprising pretreating the catalyst with a ketone or aldehyde before contacting the thus-pretreated catalyst with hydrogen and oxygen in the aqueous medium.
Claim 3
Dependent Claim
27 words
The process of claim 1, wherein the aqueous liquid contains an aldehyde or ketone and is at least 0.0001 N with respect to sulfuric of hydrochloric acid.
Claim 4
Dependent Claim
50 words
The process of claim 2, wherein the carbon base is non-graphitic and has a surface area greater than about 400 m 2 /g and the palladium catalyst is deposited on the carbon base by impregnation with a solution of palladium (II) chloride, drying, and reduction at 40°-140° C. with hydrogen.
Claim 5
Dependent Claim
16 words
The process of claim 3, wherein the aqueous liquid contains a sequestrative stabilizer for hydrogen peroxide.
Claim 6
Dependent Claim
16 words
The process of claim 2, wherein the aqueous liquid contains a sequestrative stabilizer for hydrogen peroxide.
Claim 7
Dependent Claim
23 words
The process of claim 1, wherein the carbon base is non-graphitic and has a surface area greater than about 400 m 2 /g.
Claim 8
Dependent Claim
28 words
The process of claim 1, wherein the catalyst is additionally pretreated with a dilute solution of HCl prior to or simultaneously with treatment with the aldehyde or ketone.
Claim 9
Dependent Claim
47 words
The process of claim 1, wherein the palladium catalyst is deposited on the carbon base by impregnation with a solution of palladium (II) chloride, drying, and reduction at 40°-140° C. with hydrogen for a time not substantially exceeding that required to reduce palladium (II) chloride to palladium.
Claim 10
Dependent Claim
28 words
The process of claim 1, wherein the catalyst is pretreated with an aqueous solution of an aldehyde which is at least 0.001 N with respect to hydrochloric acid.
Claim 11
Dependent Claim
110 words
In a process for producing hydrogen peroxide with a mixture of gases comprising hydrogen and oxygen with a palladium catalyst supported on a carbon base in the presence of an aqueous liquid, containing an acid and a non-acidic oxygen-containing organic compound, capable of inhibiting the decomposition of thus-produced hydrogen peroxide, the improvement wherein the carbon base is non-graphitic and has a surface area greater than 400 m 2 /g and wherein the palladium catalyst is prepared by impregnating the carbon base with a soluble palladium compound, drying the thus-impregnated carbon base and reducing the palladium compound with which the carbon base is impregnated to palladium with hydrogen at 40°-140° C.
Claim 12
Dependent Claim
110 words
In a process for producing hydrogen peroxide with a mixture of gases comprising hydrogen and oxygen with a palladium catalyst supported on a carbon base in the presence of an aqueous liquid, containing an acid and a non-acidic oxygen-containing organic compound, capable of inhibiting the decomposition of thus-produced hydrogen peroxide, the improvement wherein the carbon base is non-graphitic and has a surface area greater than 400 m 2 /g and wherein the palladium catalyst is prepared by impregnating the carbon base with a soluble palladium compound, drying the thus-impregnated carbon base and reducing the palladium compound with which the carbon base is impregnated to palladium with hydrogen at 40°-140° C.
Claim 13
Dependent Claim
27 words
The process of claim 10, wherein the aqueous liquid contains an aldehydr or ketone and is at least 0.0001 N with respect to sulfuric or hydrochloric acid.
Claim 14
Dependent Claim
16 words
The process of claim 11, wherein the aqueous liquid contains a sequestrative stabilizer for hydrogen peroxide.
Claim 15
Dependent Claim
14 words
The process of claim 10, wherein the soluble palladium compound is palladium (II) chloride.
Claim 16
Dependent Claim
78 words
In a process for producing hydrogen peroxide by contacting a mixture of gases comprising hydrogen and oxygen with a previously-reduced palladium catalyst supported on a carbon base in the presence of an aqueous liquid, containing an acid and a non-acidic oxygen-containing organic compound, capable of inhibiting the decomposition of the thus-produced hydrogen peroxide, the improvement comprising pretreating the catalyst with a dilute solution of HCl before contacting the thus-pretreated catalyst with hydrogen and oxygen in the aqueous medium.
Claim 17
Dependent Claim
78 words
In a process for producing hydrogen peroxide by contacting a mixture of gases comprising hydrogen and oxygen with a previously-reduced palladium catalyst supported on a carbon base in the presence of an aqueous liquid, containing an acid and a non-acidic oxygen-containing organic compound, capable of inhibiting the decomposition of the thus-produced hydrogen peroxide, the improvement comprising pretreating the catalyst with a dilute solution of HCl before contacting the thus-pretreated catalyst with hydrogen and oxygen in the aqueous medium.
Claim 18
Dependent Claim
23 words
The process of claim 14, wherein the carbon base is non-graphitic and has a surface area greater than about 400 m 2 /g.
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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) | 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 |