Mechanistic Study of the Direct Hydrodeoxygenation of <i>m</i>-Cresol over WO_<i>x</i>-Decorated Pt/C Catalysts

Abstract

Hydrodeoxygenation (HDO) of m-cresol to produce toluene over carbon-supported Pt and Pt-WOx catalysts was studied. In stark contrast to Pt/C that exhibits only modest selectivity and low stability for this reaction, Pt-WOx/C was found to be unusually active and selective to toluene with greater than 94% selectivity to this product while exhibiting little to no deactivation under a wide range of reaction conditions. Reactivity studies in combination with density functional theory (DFT) calculations for the adsorption and reaction of m-cresol on structurally optimized WOx-decorated Pt(111) structures indicate that the HDO reaction on Pt-WOx/C proceeds via a direct hydrogenolysis of the C–O bond in m-cresol adsorbed on oxygen vacancy (or redox) sites on WOx species. The DFT results also indicate that Pt helps stabilize the WOx film while facilitating oxygen vacancy formation.