CATALYSTS FOR SYNTHESES FROM CO AND H-2 - DEVELOPMENT OF CATALYST STRUCTURES AND REACTION-MECHANISMS

A review of papers is presented on the relation between the activity, selectivity, and preparation procedures of Ni-, Co-, and Fe-containing mono- and bimetallic catalysts derived from metal carbonyls and oxide s by precipitation, plasmochemical and mechanochemical treatments, and the structure of final catalysts for CO hydrogenation. Co and Ni are more active in CO hydrogenation, whereas Fe catalysts are more selecti ve relative to C-2 - C-4 hydrocarbon production. The activity of oxidi zed catalysts decreases, while selectivity increases. Complex structur es are developed under catalysis conditions, which consist of metal ph ases, carbides, and metal oxides in various metal oxidation states. Di fferent phases and active sites are responsible for the different stag es of the complex catalytic process. The role of carbides as plausible active phases and intermediates is discussed.