Selective hydrogenolysis of lignin in the presence of Ni3Fe1 alloy supported on zirconium phosphate

Abstract

Lignin is a promising renewable starting material for various value-added petrochemicals and high-quality fuels. However, current techniques for utilization of this natural aromatic biopolymer are challenging by the poor selectivity of desired products and the serious char formation. In this study, we provide a novel and efficient approach for selective hydrogenolysis of lignin using the cost-effective catalyst of Ni3Fe1 nanoparticles supported on zirconium phosphates. 77.0 % of lignin is converted, yielding 19.6 % monophenols, whereas, the formation of biochar is insignificant (1.7 %) at the conditions of 260 °C for 5 h in a 2.0 MPa hydrogen. Importantly, 42.1 % of these obtained monophenols are identified to be a versatile bulk chemical of para ethyl phenol (yield of 8.2 %), because of the selective cleavage of the p-coumaryl units of the lignin. The results of catalyst characterization further reveal that the formation of Ni3Fe1 nanoparticle facilitates the breakage of the specific structure of lignin and suppresses the phenolic oligomer's recondensation, which consequently enhance the lignin hydrogenolysis and char inhibition. These insights unveil that the production of bulk chemicals from sustainable resources is realizable through the rational design of catalytic processes, which substantially increase the economic feasibility of biomass biorefinery.