Charge influence on the first dehydrogenation of methanol by Ptnq (n=1-3, q=0, +1, -1): a computational study.

Abstract

Understanding the bond-cleavage ability of metal clusters is very important in various fields, such as catalysis and surface science. In this work, we performed density functional theory calculations on the first dehydrogenation process (also the key step) of methanol on Ptnq (n=1-3, q=0, +1, -1) clusters in varied charge states using quantum chemical calculations. It is shown that methanol is adsorbed much more easily to the cationic Ptn+ than to the neutral and anionic Ptn0/-. By contrast, the intrinsic bond cleavage barriers of both C-H and O-H on the cationic Ptn+ are significantly higher than on Ptn0/- (the only exception is the C-H bond cleavage on Pt+). Promisingly, injecting an electron to the neutral Ptn0 to give Ptn- can greatly reduce the C-H/O-H bond scission barrier while maintaining appreciable adsorption energy. The charging effect can be nicely interpreted by the nature of the frontier orbitals of Ptnq.