A DFT study on methanol decomposition over single atom Pt/CeO2 catalysts: the effect of the position of Pt

Pt/CeO2 catalysts exhibit excellent catalytic performance for the methanol dehydrogenation (MD) reaction. In this work, MD reactions on three systems of Pt-1/CeO2(110)), Pt-7/CeO2(110), and Pt-1/Ce1-xO2(110) are investigated via density functional theory (DFT) calculations. The CH3OH adsorption, electronic structure of the catalyst, and mechanism of methanol decomposition (MD) are systematically calculated. The results reveal that the d-band center of the Pt atom moves away from the Fermi level in the order of Pt-1/CeO2(110) < Pt-7/CeO2(110) < Pt-1/Ce1-xO2(110), and the order of the activity of the MD reaction is Pt-1/CeO2(110) < Pt-7/CeO2((1)10) < Pt-1/Ce1-xO2(110). The results of the microkinetic dynamics simulation verify that only Pt-1/Ce1-xO2(110) is conducive to the decomposition of methanol at low temperatures (373 K), and the products CO and H-2 are easily dissociated from the catalyst surface. This work uncovers that both the small size and the Ce vacancy substituted sites of Pt favor the performance of the Pt/CeO2 catalyst, and provides theoretical guidance for the construction and design of efficient metal-support catalysts for the MD reaction.