Ultrathin CoMoS Nanosheets Vertically Grown on Reduced Graphene Oxide for Selective Hydrodeoxygenation of 4-Methylphenol to Toluene

Maximizing the exposure of edge sites and achieving sufficient promotion remain arduous tasks for designing efficient bimetallic MoS2-based catalysts. Herein, ultrathin CoMoS nanosheets vertically grown on reduced graphene oxide (CoMoS/rGO-DMF) were fabricated by a facile one-pot solvothermal method using dimethylformamide (DMF) as solvent. The vertically aligned structure and good Co promotion endow CoMoS/rGO-DMF with abundant Co-Mo-S active sites and excellent catalytic performance in the hydrodeoxygenation (HDO) reaction. Consequently, CoMoS/rGO-DMF afforded a conversion of 98.2% and a toluene selectivity of 98.8% at 240 °C, 3.0 MPa, and 4 h in the HDO of 4-methylphenol. In addition, CoMoS/rGO-DMF showed a 3-fold larger turnover frequency value than that of CoMoS/rGO-DW prepared in deionized water. The reusability test of CoMoS/rGO-DMF showed a slight activity loss after six catalytic cycles, which resulted from the surface oxidation by water product, but the HDO performance of the spent catalyst can be easily regenerated by a simple sulfidation process. This work provides new insights for the rational design of sulfide catalysts with excellent HDO activity and arene selectivity.