Modulating Oxygen Vacancy in Pt/TiO<sub>2</sub> for Thermo-Photo Reforming Lignin and Its Derivatives to H<sub>2</sub> and Value-Added Product
Weidong Wu, Bowen Liu, Xueqing Qiu, Jinxin Lin, Xiaofei Wang, Xuliang Lin, Yanlin Qin
Abstract
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/TiO 2 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/TiO 2 catalyst. The density functional theory results indicate that the Pt and TiO 2 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 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.