Temperature-Dependent Hydrogenation, Hydrodeoxygenation, and Hydrogenolysis of Anisole on Nickel Catalysts

Hydrogenation stands out as one of the most promising techniques for converting biomass-derived molecules into valuable products. The expected products of upgrading biomass molecules include hydrocarbon, oxygenate, and methane. Ni-based catalysts have attracted considerable interest owing to their unique properties and relatively low cost. In this work, NiO prepared by the calcination and urea precipitation methods, namely NiO-C and NiO-U, is investigated for the hydrogenation of anisole. It is found that reaction temperature exerts a significant influence on the hydrogenation pathways. At 150 degrees C, C-reduced NiO proves more inclined towards hydrogenation, while U-reduced NiO demonstrates a tendency for hydrodeoxygenation (HDO). Moreover, as the temperature rises, both nickel catalysts change the reaction route to hydrogenolysis and eventually only produce methane at 300 degrees C, whereas metallic Ni is formed as the catalytic active phase. In situ FTIR experiments suggest the hydrogenolysis pathway and the formation of methane. This work investigates a route to produce methane from biomass molecules.