Synergistic effect for selective hydrodeoxygenation of anisole over Cu-ReOx/SiO2

Selective hydrodeoxygenation (HDO) of lignin derived oxygenated aromatic compounds has great significance for lignin utilization and chemicals production. Hereby, bifunctional catalysts of Cu-MOx/SiO2 (M = Re, Mo or W) were prepared to study the synergistic effect of Cu and MOx on the performance of anisole HDO. Characterizations indicated that Cu interacted strongly with the second metal species. As a result, more efficient sites exposed on catalysts surface, and metal dispersion and surface properties both were improved. Besides, adsorption strength for both oxygen atom and aromatic ring in reactant were all adjusted due to Cu-MOx interaction. Bimetallic catalyst Cu-ReOx/SiO2 showed the highest HDO activity, while Cu-MoOx/SiO2 and CuWOx/SiO2 both preferred transmethylation because of their prominent acid properties. The Cu-ReOx composition was found to evidently affect the anisole conversion and selectivity of benzene, toluene and xylene (BTX). The highest BTX yield of 50.5 % could be achieved when Cu/Re ratio was 3.