THE ROLE OF NITROGEN AND OXYGEN-SURFACE GROUPS IN THE BEHAVIOR OF CARBON-SUPPORTED IRON AND RUTHENIUM CATALYSTS

A carbon prepared from a copolymer Saran, and the products resulting from its reaction with NH//3 and HNO//3 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 H//2 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//2 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.