We applied periodic density-functional theory to investigate the interaction of a Pt13 cluster on graphene oxide (GO) sheets at varied ratios of oxygen to carbon and on a pristine graphene sheet. Relative to a pristine graphene sheet, the existence of oxygen atoms in an appropriate proportion in the formation of graphene oxide enhanced the adsorption capability of a Pt13 cluster. The O/C ratio of GO sheets had the following influences on the Pt13 cluster adsorption behavior: (i) for O/C ratio < 0.125, the Pt13 cluster abstracted the neighboring oxygen atom from a GO sheet to form Pt13O, or aggregated with an adjacent cluster to form a larger cluster; (ii) for O/C ratio ≥ 0.125, the Pt13 cluster was stabilized and dispersed on the GO sheet. We calculated also the adsorption behavior of carbon monoxide on a Pt13/GO sheet; a strong interaction between the Pt13 cluster and the GO sheet modulated the electronic structure of the Pt13 cluster, thus decreasing the CO adsorption energy, which in turn decreased the combined barriers, CO + O and CO + OH, in the watergas shift reaction (WGSR) and improved the CO tolerance of the Pt catalyst. (Graph Presented).
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