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

Abstract

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/Ce_1−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/Ce_1−xO₂(110), and the order of the activity of the MD reaction is Pt₁/CeO₂(110) < Pt₇/CeO₂(₁10) < Pt₁/Ce_1−xO₂(110). The results of the microkinetic dynamics simulation verify that only Pt₁/Ce_1−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.