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

Photocatalysis coupling of H2 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, H2 evolution rate and lignin and its derivative conversion were effectively facilitated. Especially, the H2 evolution efficiency in the thermo-photo reforming lignin can reach 989.7 μmol 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.