THE EFFECT OF CATALYSTS ON THE GASIFICATION OF GRAPHITE AND DIAMOND BY CARBON DIOXIDE

A comparative study was made of the effect of catalysts on the reaction of carbon dioxide at 10/sup -2/ mm and 800 deg C with graphite powder and diamond dusts. These materials have surface areas, determined by the B.E.T. method with argon, of 2.5 and 22 m/sup 2/g/sup -1/, respectively. It is shown that all graphitization of the diamond during the reaction was less than the minimum detectable by photography of the powder with x rays. The velocity of the gasification per surface unit was, for the diamond, three times more than for the graphite. Iron that is 0.8% by weight (C:Fe = 580:1), added in the form of ferric nitrate in solution, increases by 100 times the gasification velocity of the diamond and 324 times that of the graphite. A catalysis of the reaction of the diamond by sodium carbonate could not be shown because it seems that the sodium carbonate disappears during degassing. The importance of these results is discussed by reference to the theories of the catalysis of the oxidation of carbon and to the usual points of view on the structure of the diamond. (tr- auth)