Solvent Effect on the Hydroconversion of Lignin-Related Model Compounds over MoO3

Benzyloxybenzene (BOB) and oxybis(methylene)dibenzene (OBMDB) were used as lignin-related model compounds (LRMCs). Three protic solvents (PSs), i.e., methanol, ethanol (E), and isopropanol, and two aprotic solvents (ASs), i.e., ethyl acetate and n-hexane, were selected to evaluate their effects on the catalytic hydroconversion (CHC) of the LRMCs over MoO3. Under the same conditions, the PSs are more effective for the CHC of LRMCs than the ASs. Under the optimal conditions in E, both BOB and OBMDB are completely converted and the total product yields are 200 and 198.1 mol %, respectively. MoO3 undergoes the surface modification, such as carburization and oxygen vacancy (OV) formation, during the reaction, which is crucial for the CHC of the LRMCs. The OV formation is determined by the self-transformation degree of PSs and the dispersity of ASs to MoO3 through the analyses of solvent-related environmental variables. In addition, solvents affect the CHC of LRMCs by controlling the adsorption performance of MoO3.