HYDROGENATION OF CATALYTIC CARBONS OBTAINED BY CO DISPROPORTIONATION OR CH4 DECOMPOSITION ON NICKEL

The hydrogenation of catalytic carbons has been studied in the temperature range of their deposition (300-700°C) by CO disproportionation or by CH4 decomposition on nickel powders. When obtained under non carbiding conditions, the catalytic carbons are very reactive between 350 and 600°C where uncatalysed carbons are inert. The reactivity does not depend on the temperature of deposition and on preliminary heat treatment, but depends on the degree of gasification. This reactivity is imputed to the quality of the metal carbon interface which allows a good deposition-gasification reversibility. When deposition occurs under carbiding conditions, both deposition and subsequent hydrogenation are poisoned by the carbon formed by thermal decomposition of the carbide. © 1979.