Insight into the mechanism of Pt anchored graphene toward the CHx(x = 1 ∼ 4) reforming under H2 environments

• The adsorption stability of CHx species can be turned on Pt-graphene substrates.
• The CHx species can regulate the electronic and magnetic properties of Pt-graphene.
• The atomic C can be easily converted into CHx species under H environments.
• The formation of CH bond within CHx species is viewed as rate controlling step.

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 CHx 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 CHx species on the Pt/SV-graphene and the conversion processes of CHx 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 H2 molecule, the presence of H atoms can promote the conversion of CHx species and formation of new CHx+1 species. These results indicate that carbon deposition could be inhibited on Pt-modified graphene surfaces under the hydrogen environments.

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