▎ 摘　　要

The adsorption geometries and diffusion behaviors of CHx (x = 0, 1, 2, 3, 4) species on the Pt atom anchored graphene (Pt-graphene) are investigated by first-principles calculations. The adsorption of CH. species are weakly bound on the Pt embedded graphene with a single vacancy (Pt/SV-graphene) than those on the Pt anchored pristine graphene. Besides, the different kinds of CHx species can regulate the electronic structure and magnetic property of Pt-graphene systems. Moreover, the diffusion reactions of CH. species on the Pt/SV-graphene and the conversion processes of CH species (x = 1-4) under the hydrogen environments are analyzed comparatively. It is found that the deposited C atom can be easily converted into the CHx species through the hydrogenation reaction. Compared with the H-2 molecule, the presence of H atoms can promote the conversion of CHx species and formation of new CHx species. These results indicate that carbon deposition could be inhibited on Pt-modified graphene surfaces under the hydrogen environments. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.