Intrinsic Relation between Hot Electron Flux and Catalytic Selectivity during Methanol Oxidation

Abstract

Catalytic selectivity, or the production of only one desired molecule that may be used as a fuel or chemical out of several thermodynamically possible molecules, is the foundation of surface chemistry. During catalytic reactions, electronic excitation taking place on the surface creates energetic electrons called “hot electrons” that have a significant impact on catalytic reactions. Despite its importance in fundamentally understanding electronic excitation on the surface, no reports show the relation between hot electron flow and catalytic selectivity. Here, using a Pt/n-type TiO2 Schottky nanodiode, we show the intrinsic relation between hot electron flow and catalytic selectivity. On the Pt thin film, hot electron flow was generated by methanol oxidation exhibiting a two-path reaction of either full oxidation to CO2 or partial oxidation to methyl formate; a steady-state chemicurrent was detected. We show that the activation energy of the chemicurrent is quite close to that of the turnover frequency, in...