Claims
- 1. A heterogeneous catalyst comprising hollow, spherical, gas-impervious spheres formed of a refractory compound shell containing a gas at a pressure above atmospheric and having a catalytically active surface.
- 2. A catalyst according to claim 1 in which the diameter of the spheres is from 0.20 mm to 5.0 mm.
- 3. A catalyst according to claim 2 in which the shell of the spheres is formed of an oxide, nitride, carbide, silicide, boride, silicate, aluminate or mixtures thereof.
- 4. A catalyst according to claim 1 in which the catalytically active surface comprises a catalyst layer deposited on the shell.
- 5. A catalyst according to claim 1 in which the catalytically active surface is formed by catalytically active materials present in the shell.
- 6. A catalyst according to claim 4 in which the catalyst layer includes a catalytic metal.
- 7. A catalyst according to claim 6 in which the catalytic metal is selected from transition metals and noble metals and the catalyst layer includes an activator and/or promoter.
- 8. A catalyst according to claim 1 in which the gas is air.
- 9. A catalyst according to claim 2 in which the density of the spheres does not vary more than 0.5 percent by weight.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of Ser. No. 602,901, filed Apr. 23, 1984, Now U.S. Pat. No. 4,576,926.
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 83-568 (72 Stat 435; 42 USC 2457).
US Referenced Citations (7)
Foreign Referenced Citations (2)
Number |
Date |
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763944 |
Jul 1967 |
CAX |
2055787 |
Mar 1981 |
GBX |
Continuation in Parts (1)
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Number |
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602901 |
Apr 1984 |
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