US4313806A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cathodic protection of catalysts in a corrosive environment
Assignee: Air Products and Chemicals Inc
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Filing: 1980-10-10
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Granted: 1982-02-02
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Expires: 2000-10-10
Abstract
Abstract Dissolution of Group VIII supported metal catalysts from semi-conductive or conductive carriers in liquid media containing a strong inorganic acid is stopped by making the Group VIII noble metal cathodic with respect to an anode placed in the reactor. A representative embodiment is in processes for synthesis of hydrogen peroxide from its elements.
Inventors
- 👤 Augustine I. Dalton, Jr.
- 👤 Ronald W. Skinner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:33
CPC Classifications
C; C23; C23F; C23F13/00; C23F13/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
69 words
A process for preventing dissolution of a Group VIII noble metal catalyst from a conductive or semiconductive carrier in a corrosive or oxidatively active liquid environment, comprising polarizing the Group VIII noble metal surface on the conductive or semiconductive carrier so as to render the polarized Group VIII noble metal surface cathodic with respect to an anode placed in a reactor containing the corrosive or oxidatively active liquid environment.
Claim 2
Dependent Claim
69 words
A process for preventing dissolution of a Group VIII noble metal catalyst from a conductive or semiconductive carrier in a corrosive or oxidatively active liquid environment, comprising polarizing the Group VIII noble metal surface on the conductive or semiconductive carrier so as to render the polarized Group VIII noble metal surface cathodic with respect to an anode placed in a reactor containing the corrosive or oxidatively active liquid environment.
Claim 3
Dependent Claim
50 words
The process of claim 1, wherein the corrosive environment is that used in the liquid phase catalytic reaction of hydrogen and oxygen to form hydrogen peroxide in a liquid capable of stabilizing the hydrogen peroxide thus produced against decomposition, the liquid containing water and at least one strong inorganic acid.
Claim 4
Dependent Claim
14 words
The process of claim 2, wherein the Group VIII noble metal catalyst is palladium.
Claim 5
Dependent Claim
11 words
The process of claim 2, wherein the conductive carrier is carbon.
Claim 6
Dependent Claim
12 words
The process of claim 2, wherein the corrosive environment is aqueous acetone.
Claim 7
Dependent Claim
16 words
The process of claim 2, wherein the strong inorganic acid is hydrochloric acid or sulfuric acid.
Claim 8
Dependent Claim
15 words
The process of claim 2, wherein the corrosive environment contains hydrochloric acid and sulfuric acid.
Claim 9
Dependent Claim
26 words
The process of claim 2, wherein the catalyst is palladium supported on carbon and the corrosive environment is aqueous acetone containing hydrochloric acid and sulfuric acid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-02-01 | 1985-08-03 | 1986-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-01 | 1989-08-03 | 1990-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-01 | 1993-08-03 | 1994-02-02 | $7700.00 | Window Closed / Lapsed |