Hydrogenolysis of organosolv hydrolyzed lignin over high-dispersion Ni/Al-SBA-15 catalysts for phenolic monomers

Efficiency and recycling of catalysts are important for the lignin hydrogenolysis to obtain phenolic monomers. In this work, a series of high-dispersion Ni/Al-SBA-15 catalysts were prepared by a direct and effective preparation method, and then used in the hydrogenolysis of diphenyl ether(DE) and organosolv hydrolyzed lignin(OHL) for phenolic monomers. The universality of as-made catalysts in different solvents and cyclic performance were investigated. Results showed that the addition of ethylene glycol(EG) during the loading process of Ni promoted the dispersion of metal efficiently. High dispersion of Ni species could highly enhance the conversion of DE and the OHL which Ni/Al-SBA-15(1 EG) exhibited the excellent catalytic performance. Decalin was found to be most effective solvent on the conversion of DE(99.16%). 84.77% liquefaction ratio and 21.36% monomer yield were achieved, and no obvious char was observed after the depolymerization of OHL in ethanol solvent at 280 ℃ for 4 h over the Ni/Al-SBA-15(1 EG) catalyst.