Methanation of CO over Ni catalyst: A theoretical study

Abstract

Theoretical methods (generalized valence-bond calculations) were used to examine the bond energies and geometries of numerous species chemisorbed onto Ni clusters representing Ni surface. These results were used to obtain thermochemical information and to examine various mechanisms for the methanation of CO over Ni: CO+3H2 →(Ni) CH4+H2O. It is found that chemisorbed formyl radicals (Ni–CHO) lead to a favorably appearing chain reaction that is consistent with current experimental results. In addition, we find a chemisorbed C2 species that may be the catalytically active Cad formed from dissociation of CO.