Density functional theory study into the adsorption of CO2, H and CHXx (x=0-3) as well as C2H4 on α-Mo2C(0001)

The structures and energetics of the chemisorbed CO2, CH4 species and H as well as C2H4 on the alpha-Mo2C(0001) surface have been computed at the GGA-RPBE level of density functional theory. It is found that CO2 adsorbs dissociately into CO and O, in agreement with the experimental finding. The adsorbed O, CHx and H species prefer the site of three surface molybdenum atoms over a second layer carbon atom (V-C site). On the basis of the calculated adsorption energies of CHx and H, the sequential dehydrogenation of CH4 and the C/C coupling reaction of CHx have been discussed. (c) 2006 Elsevier B.V. All rights reserved.