Catalytic roles of Mo-based sites on MoS2 for ethanolysis of enzymatic hydrolysis lignin into aromatic monomers

Abstract

| openaire: EC/H2020/101006744/EU//EHLCATHOL Funding Information: This work is supported by the National Natural Science Foundation of China (21808163 and 21690083). This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 101006744. The content presented in this document represents the views of the authors, and the European Commission has no liability in respect of the content. Funding Information: This work is supported by the National Natural Science Foundation of China ( 21808163 and 21690083 ). This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 101006744 . The content presented in this document represents the views of the authors, and the European Commission has no liability in respect of the content. Publisher Copyright: © 2022 The Authors ; The depolymerization of enzymatic hydrolysis lignin (EHL) is examined over one-step hydrothermal-synthesized MoS2 in ethanol without hydrogen gas. Value-added aromatic molecules, mainly including alkyl-substituted phenols (A-Ps), are obtained without char or tar formation. The MoS2 samples prepared with different Mo and S precursors have been tested and the highest aromatic monomer yield of 226.4 mg/g EHL is achieved over the MoS2 prepared with thioacetamide and sodium molybdate as precursors (STA-MoS2) at 320 °C for 12 h. Proper ratios of Mo6+/Mo5+ (~0.46–0.65) and (Mo6++Mo5+)/Mo4+ (~0.47–0.62) on the surface of MoS2 catalysts are found to be significant for the achievement of high overall aromatic monomer yield. MoOxSy species with Mo5+ and S22- is proposed as the active site for the production of complex alkyl phenols via demethoxylation and alkylation. The carbon deposition and the exchanges of sulfur and oxygen atoms resulted from the oxidization are likely responsible for the deactivation of catalyst. ; Peer reviewed