Abstract
Dehydrogenation of H(3)COH and H(2)O are key steps of methanol steam reforming on transition metal surfaces. Oxhydryl dehydrogenation reactions of H(x)COH (x = 0-3) and OH on Ni (111) were investigated by DFT calculations with the OptB88-vdW functional. The transition states were searched by the climbing image nudged elastic band method and the dimer method. The activation energies for the dehydrogenation of individual H(x)COH* are 68 to 91 kJ/mol, and reduced to 12-17 kJ/mol by neighboring OH*. Bader charge analysis showed the catalysis role of OH* can be attributed to the effect of hydrogen bond (H-bond) in maintaining the charge of oxhydryl H in the reaction path. The mechanism of H-bond catalysis was further demonstrated by the study of OH* and N* assisted dehydrogenation of OH*. Due to the universality of H-bond, the H-bond catalysis shown here, is of broad implication for studies of reaction kinetics.