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

Abstract

Lignin, rich in β‐O‐4 bonds and aromatic structure, is a renewable and potential resource for value‐added chemicals and promoting H2 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/VZn‐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 H2 evolution and accompany the selective oxidation of lignin model from Cα‐OH to Cα = 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.

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

“…Then, different lignin derivatives have been used for thermo-photo reforming over Pt/TiO 2 –O V (M) (Table ). The differences exhibited by the thermo-photo reforming efficiencies are due to the differences in substituent electronic effects and electrostatic potentials . Besides that, the reforming activity of Pt/TiO 2 –O V (M) did not significantly reduce after five cycles (Figure d).…”

“…The differences exhibited by the thermo-photo reforming efficiencies are due to the differences in substituent electronic effects and electrostatic potentials. 43 Besides that, the reforming activity of Pt/TiO 2 −O V (M) did not significantly reduce after five cycles (Figure 3d). The results of XRD and XPS further indicated the structural stability of Pt/TiO 2 −O V (M) after the thermo-photo reforming process (Figures S14 and S15).…”

“…52 The absorption peak appearing near 1700 cm −1 can be attributed to ν(C�O) vibration, indicating the formation of aldehyde groups. 43 The negative absorption peak at 3683 cm −1 and the broad absorption peak at 3481 cm −1 are caused by hydroxyl group interference (Figure S22). 53 The above results suggest that the alcohol hydroxyl group of 4-MBA forms a strong adsorption on the Pt/TiO 2 −O V (M) surface, which facilitates the alcohol hydroxyl group oxidation during thermo-photo reforming reaction.…”

Highly Efficient Conversion of Lignin into Diethyl Maleate Catalyzed by Molybdenum-Based Hybrid Catalysts

“…The conversion of biomass into chemicals has become a priority for reducing dependence on fossil fuels and mitigating greenhouse gas emissions. − Biomass is a renewable source of carbohydrates that immobilizes CO 2 , producing approximately 170 billion tons per year. ,− Lignin, a natural aromatic heteropolymer, accounts for ∼40% of the energy content and 10–35% of the weight of lignocellulosic materials . Lignin is composed of sinapyl alcohol, coniferyl alcohol, and p -coumaric alcohol, which are connected by β-O-4, β-5, 5-5, and other linkages. , Despite the abundance of lignin, only ∼3% is currently utilized for commercial applications, and the rest is typically burned, resulting in air pollution . Consequently, an efficient valorization strategy is required for the effective utilization of lignin.…”

“…7 Lignin is composed of sinapyl alcohol, coniferyl alcohol, and p-coumaric alcohol, which are connected by β-O-4, β-5, 5-5, and other linkages. 8,9 Despite the abundance of lignin, only ∼3% is currently utilized for commercial applications, 10 and the rest is typically burned, resulting in air pollution. 11 Consequently, an efficient valorization strategy is required for the effective utilization of lignin.…”