E. Shustorovich, A. Bell
Oct 1, 1988
Citations
1
Influential Citations
65
Citations
Journal
Journal of Catalysis
Abstract
The bond-order-conservation (BOC) method has been used to identify the energetics associated with the hydrogenation of CO over (111) surfaces of Ni, Pd, and Pt. In the formation of CH{sub 4}, the C-O bond of CO is cleaved. BOC calculations for Ni indicate that cleavage of the C-O bond occurs primarily by direct dissociation of molecularly adsorbed CO. The activation energy for direct dissociation of CO on Pd and Pt is significantly greater than that for hydrogen assisted dissociation, and hence the latter process is more significant. The BOC calculations indicate that for these metals the species from which C-O bond cleavage occurs is CH{sub 3}O{sub 5}. Because the activation barriers for CH{sub 3}O{sub 5} dissociation and hydrogenation to form CH{sub 3}OH are close for Pd and Pt, these metals are effective catalysts for both CH{sub 4} and CH{sub 3}OH synthesis. By contrast, the BOC method predicts that CH{sub 4} should be the principal product formed over Ni. 36 refs.