Modulating Oxygen Vacancy in Pt/TiO₂ for Thermo-Photo Reforming Lignin and Its Derivatives to H₂ and Value-Added Product

Photocatalysis coupling of H-2 evolution and lignocellulose oxidation remain great foreground, but slow photodynamic process limits its development. Here, we explored the effect of defect engineering on the electronic structure and d-band center of the Pt/TiO2 catalyst. Oxygen vacancies lead to the delocalization of electrons near the O atom, and the d-band center moves down, which will redistribute electrons and facilitate the desorption of intermediates of the Pt/TiO2 catalyst. The density functional theory results indicate that the Pt and TiO2 surfaces form electron-rich and electron-deficient regions, respectively. Meanwhile, in situ electron paramagnetic resonance shows that the thermal energy accelerated the generation of free radicals. Thus, H-2 evolution rate and lignin and its derivative conversion were effectively facilitated. Especially, the H(2 )evolution efficiency in the thermo-photo reforming lignin can reach 989.7 mu mol g(-1) h(-1), which is 18.2 times that of photo reforming. This work not only delves deeply into the modulation of the electronic structure of defect-type catalysts but also offers new insights into the efficient conversion and utilization of lignin-based biomass.