Zinc Vacancy Promotes Photo-Reforming Lignin Model to H₂ Evolution and Value-Added Chemicals Production

Lignin, rich in beta-O-4 bonds and aromatic structure, is a renewable and potential resource for value-added chemicals and promoting H-2 evolution. However, direct photo-reforming lignin remains a huge challenge due to its recalcitrant structure. Herein, a collaborative strategy is proposed by dispersing Pt on zinc-vacancy-riched ZnIn2S4 (Pt/V-Zn-ZIS) for revealing the effect of lignin structure during photo-reforming process with lignin models. And a series of theoretical calculations and experimental results show that lignin model substances with more nucleophilic group structures will have a stronger tendency to occur the photo-reforming reactions. In addition, benefiting of Pt-S electronic channel is formed by occupying Pt atom onto zinc vacancies in ZnIn2S4, which can effectively reduce the energy barrier of H-2 evolution and accompany the selective oxidation of lignin model from C alpha-OH to C alpha = O under simulated sunlight. The natural lignin is used to further demonstrate this selective oxidation mechanism. The presented work demonstrates the photo-reforming lignin model mechanism and the influence of lignin-structure during the process of photo-reforming.