Fig. 1: Schematic illustration of a model heterogeneous platform composed of CeOx nanowire arrays with modulated physicochemical properties on Pt catalysts (CeOx/Pt) for an accurate analysis of their role and influence on methyl formate (MF) selectivity toward methanol oxidation reaction (MOR).
Two different methods are utilized to evaluate the partial oxidation selectivity of each catalyst: electrical signal (hot electron flux) using ammeter and sensing signal (Turnover frequency and MF detection) using gas chromatography. Crystallinity gives well-formed and evenly distributed active sites that can enhance both reaction rates and MF selectivity compared to the amorphous state. Moreover, the oxygen vacancies within the ceria induce electron accumulation at the heterogeneous interfaces and as a result, supply more electrons to the reactant molecules for alkoxy hemiacetal formation. Therefore, the activation barrier for alkoxy hemiacetal formation is reduced, leading to highly improved MF selectivity, thereby generating enhanced hot electron flux.
