Fischer Tropsch synthesis: Deuterium isotopic study for the formation of oxygenates over CeO2 supported Pt–Co catalysts

Abstract

The effect of deuterium on Fischer-Tropsch (FT) synthesis was investigated over a Pt promoted Co/CeO2 catalyst. CeO2 supported Pt–Co catalyst is more selective towards methane and oxygenates. H2–D2–H2 switching experiments suggest that the hydrogenation of CO is involved in the rate determining step (inverse isotope effect). The suppression of oxygenate formation with deuterium leads to the conclusion that common FT intermediates are responsible for the observed shift in the product spectrum. The deuterium isotopic study supports our previously proposed mechanism for the formation of alcohols in that the Co–CeO2 interface is involved in the catalysis, such that termination of chain growth occurs at the metal–oxide junction and involves bridging OH groups on partially reduced ceria.