Insight into H ₂ adsorption and activation over Pt-WO _<i>x</i> sites for glycerol efficient hydrodeoxygenation

Pt-WO<em>_x</em>-based catalysts, known for their bifunctional nature, have shown promise in selective hydrodeoxygenation (HDO) reactions. Gaining insights into the activation process of H₂ and the origin of Brønsted acidity on Pt-WO<em>_x</em> sites is essential for enhancing reaction performance. In this work, we have developed a methodology to meticulously regulate the domain size of WO<em>_x</em> species on SBA-15 support by utilizing the in-situ hydrolysis of WCl₆ with the hydroxyl groups on SBA-15. This approach allowed us to achieve different polymeric degrees of WO<em>_x</em> species on SBA-15. Notably, the low polymeric WO<em>_x</em> species associated with Pt, demonstrated significantly augmented catalytic activity in glycerol hydrogenolysis to 1, 3-propanediol. The adsorption and activation of H₂ on such catalysts were systematically examined using in-situ DRIFTS. It was found that the Pt-WO<em>_x</em> interface facilitates the heterogeneous dissociation of H₂, generating hydride species (W-OH^δ+) that act as Brønsted acid sites, thereby enhancing catalytic activity. Our findings offer a new perspective on understanding the HDO reaction mechanism and provide valuable insights for the development of highly efficient catalysts for such reactions.