Effects of Cobalt on Synthesis Gas Reactions over Copper-Based Catalysts

Abstract

Typically, in the heterogeneously catalyzed hydrogenation of carbon monoxide, copper-based catalysts are very selective for the synthesis of methanol, while cobalt-based catalysts exhibit Fischer-Tropsch activity with high selectivity to hydrocarbons. Mixed copper-cobalt catalysts have been reported to show, in various degrees [1–4], selectivity for higher alcohol formation. Of particular interest are the copper-cobalt catalysts developed by Sugier and co-workers [3,4] at the Institut Francais du Petrole (IFP). Most of these catalysts contain aluminum, chromium or zinc, and small amounts of alkali, so that their composition corresponds to that of alkalized conventional copper-based methanol synthesis catalysts modified by the addition of cobalt. With these catalysts, high yields of higher alcohols were obtained under methanol synthesis conditions, and, in contrast with other copper-cobalt systems [1–2], there was no appreciable methanation, and little [3] or moderate [4] formation of higher hydrocarbons.