Ruthenium carbonyl clusters, adsorbed on oxide supports and thermally decomposed under hydrogen, are very active catalysts for the methanation of both carbon monoxide and carbon dioxide.

The catalysis of carbon monoxide hydrogenation by supported cobalt and ruthenium clusters is studied, and an unusually specific cobalt methanation catalyst is described. A variety of ruthenium carbonyl clusters catalyzes carbon monoxide methanation, irrespective of support, and Ru3(CO)12 on γ-alumina is found to be a potentially useful carbon dioxide methanation catalyst.