In situ hydrogenation is a novel method for hydrogenating complex
chemical compounds [12,13]. Liquid hydrogenation donors
were used during the hydrogenation process instead of hydrogen
gas. Tan [14] and Fisk [15] used acids as hydrogenation donors
for hydrogenating bio oil model compounds and raw bio-oil. But
the study on the effects of the coupling and the application for in
situ hydrogenation are still lacking. Ford [16] investigated the
approach to disassembling biomass-derived lignin in supercritical
methanol over Cu-doped porous metal oxide catalyst. The hydrogen
generated from methanol transferred to the organosolv lignin.