Suchergebnisse

| openaire: EC/H2020/101006744/EU//EHLCATHOL This work is supported by the National Natural Science Foundation of China (21808163). 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. ; Low selectivity and complex product distribution are the main challenges for the utilization of lignin. Herein, the selective production of 2-(tert-butyl)-3-methylphenol (TBC), an antioxidant in the polymer industry, from depolymerization of enzymatic hydrolysis lignin (EHL) on a hydrothermally synthesized MoS2 catalyst is studied. The total aromatic monomer yield is 124.1mg/g EHL and the selectivity of TBC is up to 40.3wt% in methanol at 280oC under 2MPa H2 for 6h. The FT-IR analysis of products reveals that MoS2 has a high activity for demethylation, dehydroxylation and alkylation, and the dimer conversions reveal that C-O and C-C bonds in EHL are broken with MoS2. The guaiacol and its derivants are identified as the intermediate for formation of TBC in EHL depolymerizaiton according to the effect of time on product distribution and monomer converison. ; Peer reviewed

| 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

| openaire: EC/H2020/101006744/EU//EHLCATHOL This work has received funding from the European Union's Horizon 2020 research and innovation program, (BUILDING A LOW-CARBON, CLIMATE RESILIENT FUTURE: SECURE, CLEAN AND EFFICIENT ENERGY) 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. This work was also supported by the National Natural Science Foundation of China (21808163 and 21690083). ; A Mo(OCH2CH3)x/NaCl catalyst showed high efficiency in supercritical ethanol without adding H2 in the conversion of Kraft lignin to chemicals, including C6 alcohols, C8-C10 esters, benzyl alcohols and arenes. Control experiments were done with MoCl5, NaOC2H5 and the physical mixture of them. The Mo(OCH2CH3)x/NaCl catalyst exhibited superior activity among the samples examined. The overall yield increased as the reaction temperature increased from 260 to 300 °C. The yield of aromatic compounds achieved 303mg/g lignin over the Mo(OCH2CH3)x/NaCl catalyst at 300oC for 6h. MoCl5 and NaOC2H5 forms Mo(OCH2CH3)x in the catalyst preparation, which behaves as the active species in Kraft lignin conversion. The primary aromatics formed from the catalytic lignin depolymerization steps may undergo secondary reactions to form the final products. ; Peer reviewed