Selective hydrogenolysis of C-O bonds in lignin and its model compounds over a high-performance Ru/AC catalyst under mild conditions

• Catalysts of Ru supported on AC from coal tar pitch were successfully synthesized. • Ru/4-1AC exhibited the best catalytic performance for the cleavage of C-O bonds. • BPE was preferentially adsorbed on Ru metal for the C-O bond cleavage than DPE. • The reaction pathways of DPE and BPE were explored and analyzed in detail. • Oxygenated low-molecular-weight products were obtained from lignin over Ru/4-1AC. Selective hydrogenolysis of C-O bonds in lignin is regarded as the most promising strategy to produce high value-added biofuels and chemicals. Herein, Ru/AC catalysts of Ru supported on AC from coal tar pitch were successfully prepared and could effectively promote the cleavage of C-O bonds in diphenyl ether (DPE), benzyl phenyl ether (BPE) and lignin under mild conditions. In the case of an activation ratio of 4:1, the obtained Ru/4-1AC possessed the large specific surface area, more defects, small Ru metal particle size and low Ru 0 bonding energy, exhibiting the high catalytic performance. The conversion investigation of the mixture of DPE and BPE revealed that BPE was preferentially adsorbed on Ru metal of the catalyst surface for the C-O bond cleavage due to the lower bond dissociation energy of C-O bonds of BPE and the stronger adsorption energy of BPE calculated by a density functional theory.