Methanol Oxidation on Platinum Catalyst: Why does the Negatively Charged Surface Perform Better Than the Neutral One?

摘要

Platinum (Pt) is a star catalyst that is now widely used in electrode reactions. Very recently, growing experimental evidences have shown that injection of electrons to the Pt catalyst could improve the surface catalytic reactivity to reactant (e. g. the CH3OH). However, the underneath molecular mechanism remains unclear. In this work, by performing density functional theory calculations, we for the first time studied the methanol dehydrogenation on the single layer of the Pt lattice (Pt_(13)) under the conditions of electronic neutrality and injection of one electron. On neutral Pt_(13), the O-site is the more preferred adsorption than the methyl-site, though the latter can kinetically induce more facile bond cleavage. By sharp contrast, on anionic Pt_(13) -, the methyl-site is both the more preferred adsorption and can induce the more facile bond cleavage. Thus, the cooperation of the adsorption and bond cleavage caused by the electron injection is responsible for the enhanced catalytic ability of the negatively charged Pt catalyst