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 Pt1/CeO2(110)), Pt7/CeO2(110), and Pt1/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 Pt1/CeO2(110) < Pt7/CeO2(110) < Pt1/Ce1-xO2(110), and the order of the activity of the MD reaction is Pt1/CeO2(110) < Pt7/CeO2(110) < Pt1/Ce1-xO2(110). The results of the microkinetic dynamics simulation verify that only Pt1/Ce1-xO2(110) is conducive to the decomposition of methanol at low temperatures (373 K), and the products CO and H2 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.