Abstract: Compositions of matter useful as catalysts in heterogeneous reactions and comprising metal atom clusters supported on inorganic supports such as silica, alumina or zeolites are prepared by vaporizing the metal at low temperatures and pressures into an environment of ethylene and a gaseous inert solvent. A metal-ethylene complex, protected by solvent molecules is formed. The complex is melted to liquid phase and used to impregnate the support. Then the material is warmed to ambient temperature to remove the solvent, decompose the complex and form monatomic or clusters of metal on the support.

Abstract: Metal catalysts for use in known heterogeneous catalysis processes are prepared by vaporizing a metal in a low pressure environment in the vicinity of an organic liquid polymer, so that the metal contacts and becomes anchored to the polymer. The resulting products have the metal in the form of small clusters, anchored to the polymer, this form of the metal being the catalytically most active form. The organometal polymers are stable at temperatures in the -40.degree. C..fwdarw.+40.degree. C. range. Suitable polymers include poly (methyl-phenyl siloxanes) and poly (phenyl ethers). Suitable metals include titanium, chromium, molybdenum, etcetera.