Catalytic transfer hydrogenolysis of lignin launched by the chemo-splitting of water

Conversion of lignin to value-added chemicals with endogenous hydrogen is of great significance but highly challengeable. In this work, an external hydrogen-free strategy has been proposed for aqueous transfer hydrogenolysis of lignin launched by the chemo-splitting of water using a series of Ni-Co bimetallic catalysts. With Ni 0.2 Co 0.1 -MgAl-LDO, 82.7 % of lignin conversion was achieved, affording a 20.8 % yield of monophenols, and 62.0 % of which was identified as 4-ethylphenol (yield of 12.9 %). Further investigations demonstrated that the lignin hydrogenolysis was triggered by the water splitting, and enhanced by the tandem demethoxylation and subsequent aqueous reforming reaction. Intensive characterizations using TEM, XPS and XAFS, etc, illustrated that the formation of highly dispersed Ni-Co alloy nanoparticles exhibited a strong metal-support interaction with MgAl-LDO. The electronic transfer effect between Ni and Co components and the strong basic sites are responsible for its excellent catalytic performance of Ni 0.2 Co 0.1 -MgAl-LDO on the lignin hydrogenolysis. Therefore, this work provides novel insight into the catalytic transfer hydrogenolysis of lignin.