A carbon prepared from a copolymer Saran, and the products resulting from its reaction with NH, and HNO, under different experimental conditions to introduce nitrogen and oxygen surface groups, have been used as supports for Fe and Ru catalysts. The catalysts have been characterized by HZ and CO chemisorption, X-ray line broadening and transmission electron microscopy were used to estimate metal particle sizes. There is, for Fe catalysts, an increase in hydrogen uptake and a decrease in CO uptake with increasing nitrogen content of the support and a decrease of both uptakes with increasing oxygen content. There is, however, in the case of Ru, an increase in both H, and CO uptake with increasing nitrogen content of the support.
The results obtained in the hydrogenation of CO at 523 K and 101 KPa do not, in all cases, follow the sequence observed in the chemisorption experiments; it seems as if the functional groups introduced on the carbon are not sufficient to produce sensible changes in activity or selectivity of the catalysts in this reaction. Some effect is observed only in highly dispersed Fe catalysts supported on carbons treated with ammonia. Moreover, the hydrogenolysis of n-butane at 573 K (Fe catalysts) or 413 K (Ru catalysts) seems to be clearly affected by the nitrogen content of the support, especially in catalysts prepared from Fe(CO),.