Deep oxidation of propane over WO3 - promoted Pt/BN catalysts: The critical role of Pt - WO3 interface

The addition of WO3 in the Pt/BN catalyst significantly promotes the performance for deep oxidation of propane. A catalyst with a W content of 7 wt.% (1 Pt-7 W/BN) has the highest activity (a reaction rate of 367.1 mu mol g(Pt)(-1) s(-1) at 220 degrees C), which is 7-fold as high as that on the 1 Pt/BN (a reaction rate of 52.4 mu mol g(Pt)(-1) s(-1)). The W-promoted catalysts are stable under dry and wet reaction conditions, showing promising potential in practical applications. Based on detailed kinetics and in-situ diffuse reflectance infrared spectroscopy results, the Pt-WO3 interfacial sites serve as new active sites which are responsible for the improved activity. The facile reaction between propane adsorbed on Pt atom and surface hydroxyl groups on adjacent WOx accelerates the cleavage of the C-H bond, which is the kinetically essential step in this reaction system.