On the Catalytic Activity of Pt Supported by Graphyne in the Oxidation of Ethanol

摘要

abstract_textpThe adsorptions of Pt clusters on beta- and gamma-graphyne (beta-GY, gamma-GY), graphdiyne (GDY), and graphene (GP) were extensively investigated with density functional theory. Ethanol adsorption and its partial oxidation on the Pt supported by the GY and GP were then explored to address the influence of the supporting materials on the activity of Pt nanoclusters in ethanol oxidation. Among the examined adsorption sites such as the hollow, CspCsp, and C-sp-C-sp2 bonds, the hollow site consisting of multiple triple bonds is the most attractive one to adsorb Pt and Pt-4 regardless of beta-GY, gamma-GY, and GDY. The binding of Pt-4 to the GDY is slightly stronger than those of beta-GY and gamma-GY (binding energy: -4.08 vs -3.64 and -3.73 eV). It is remarkable that the adsorption of Pt-4 on GY is 2-3 times stronger than that on GP (-3.6-4.1 vs -1.3 eV), showing that the GY and GDY are better substrates than the GP for the stability of Pt clusters. Furthermore, the potential energy profiles for the oxidation of ethanol show that in spite of the higher energy barrier for the adsorbed ethanol on Pt4 supported by gamma-GY than by GP (1.54 vs 1.19 eV), the dehydrogenation intermediate and product of ethanol on Pt-graphyne are more stable than that on Ptgraphene, suggesting that graphyne is thermodynamically more favorable than graphene as a substrate for the Pt catalyst./p/abstract_text