Nb2C MXene assisted CoNi bimetallic catalysts for hydrogenolysis of aromatic ethers

Hydrogenolysis of biomass-derived lignin sources is highly important for the conversion of renewable biomass resources to biofuels. However, lots of developed catalysts suffer from the drawbacks of expensive precious metal catalysts and/or operation under harsh conditions. In the present work, Co–Ni bimetallic catalysts were prepared and applied in catalyzing hydrogenolysis of Caryl–O aromatic ethers with high activities under the promotion of Nb2C MXene additive. Especially, the hydrogenolysis of diphenyl ether (DPE), a 4–O–5 model compound, to cyclohexane (cy) and cyclohexyl alcohol (cy-ol) could be achieved over the Co2Ni1Ox–Nb2C MXene catalytic system at 120 °C and under 5 bar of H2, which are mild conditions in comparison with those for the developed heterogeneous precious-metal-free catalysts. The excellent catalytic performances stemmed from the strong interaction between Co and Ni species and the promotion of Lewis acidic sites offered by Nb2C MXene. The proposed reaction pathway involved the direct hydrogenolysis of DPE route, in which DPE was initially hydrogenolyzed to benzene and phenol. They were further hydrogenated to cy and cy-ol. The present work not only develops a noble-metal-free bimetallic catalyst for utilization of biomass-derived lignin sources, but also provides a novel strategy for using the Nb2C MXene material.