Regulating the C–H Bond Activation Pathway over ZrO2 via Doping Engineering for Propane Dehydrogenation

Abstract

The efficient activation of the C–H bond in light alkanes and their catalyst design are significant for alkane-related catalytic processes in view of theoretical and practical aspects. Here, we report the C–H bond activation mechanism and structure–reactivity relationships of Ga-doped ZrO2 catalysts in propane dehydrogenation. Experimental and theoretical calculation results suggest that the introduction of Ga into the framework of ZrO2 alters the C–H bond activation pathway from a stepwise mechanism to a concerted mechanism involving simultaneous cleavage of two C–H bonds in propane, leading to a superior C–H bond activation ability and a lower reaction barrier than state-of-the-art metal oxide catalysts. In addition, a volcano-type dependence of the rate of propene formation on the Ga/Zr ratio is established due to a compromise of intrinsic activity and active site concentration. The strategy of metal incorporation into bulk metal oxide may provide an alternative solution to control the C–H bond activation pathway for efficient propene production.