Catalytic reduction of pyrolyzed biomass is required to remove oxygen and produce transportation fuels, but limited knowledge of how hydrodeoxygenation (HDO) catalysts work stymies the rational design of more efficient and stable catalysts, which in turn limits deployment of biofuels. This work reports results from a novel study utilizing both isotopically labeled phenol (which models the most recalcitrant components of biofuels) with D 2 O and DFT calculations to provide insight into the mechanism of the highly efficient HDO catalyst, Ru/TiO 2 . The data point to the importance of interface sites between Ru nanoparticles and the TiO 2 support and suggest that water acts as a cocatalyst favoring a direct deoxygenation pathway in which the phenolic OH is replaced directly with H to form benzene. Rather than its reducibility, we propose that the amphoteric nature of TiO 2 facilitates H 2 heterolysis to generate an active site water molecule that promotes the catalytic C−O bond scission of phenol. This work has clear implications for efforts to scale-up the hydrogen-efficient conversion of wood waste into transportation fuels and biochemicals.
The structure of supported platinum and platinum-tin nanoparticles was investigated by Pt L(3) high-energy resolution fluorescence detected X-ray absorption spectroscopy (HERFD XAS) and resonant inelastic X-ray scattering (RIXS). The incorporation of tin decreased the ability of particles to adsorb both hydrogen and carbon monoxide due to tin enrichment on the surface. The platinum d band of platinum-tin particles was narrower and was shifted down relative to the Fermi level in comparison to platinum particles. The difference in electronic structure between pure and alloyed particles persisted after adsorption of hydrogen. The Pt-H antibonding state was clearly identified for the pure platinum particles. The strong adsorption of carbon monoxide changed the geometric structure of the PtSn particles. After carbon monoxide adsorption, the geometric structures of both systems were very similar. Room temperature adsorption of carbon monoxide affects the structure of platinum catalysts.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.