Selective hydrogenolysis of lignin for phenolic monomers with a focus on β-O-4 cleavage and C = O hydrodeoxygenation

Catalytic hydrogenolysis of lignin for the production of phenolic monomers has received a lot of attentions. During the hydrogenolysis process, the cleavage of beta-O-4 is important for high conversion and the hydrodeoxygenation of C = O is favor for high selectivity of monophenols. Herein, multiple functional metal modified molybdenum carbide catalyst was designed for beta-O-4 cleavage and C = O hydrodeoxygenation in lignin and model compound. Experiments coupled with various characterization methods (X-ray diffraction, chemisorption-desorption, X-ray photoelectron spectroscopy) showed that the combined acidity and hydrogenation performance of molybdenum carbide was modified by Ni metal, and was beneficial for the complete cleavage of beta-O-4. Meanwhile, due to the synergistic effects between Ni and Cu/Fe, the totally hydrodeoxygenation of C = O was also obtained without excessive hydrogenation of benzene rings. Moreover, by using Ni7Fe3-Mo2C/AC as the catalyst, maximally 35.42% of phenolic monomers and 85.11% of ethyl acetate soluble products from corn straw lignin hydrogenolysis were obtained.