Catalytic self-transfer hydrogenolysis of lignin over Ni/C catalysts

Lignin is composed of phenylpropyl alcohol through the C-O and C-C bonds, where β-O-4 accounts for the majority. Self-transfer hydrogenolysis (STH) is a promising method to produce valuable chemicals and fuels from lignin by cleaving the β-O-4 bond without exogenous hydrogen, but all the reported work used noble metal-based catalysts. In this work, a highly efficient Ni/C catalyst was derived from a Ni-containing metal-organic framework (Ni-MOF), and its self-transfer hydrogenolysis performance towards ether bonds in lignin model compounds was evaluated using 2-phenoxy-1-phenylethanol as a model compound in detail. It was found that the catalyst pyrolyzed under a nitrogen atmosphere at 500 °C (Ni-NDC-500) was very efficient for the reaction. Moreover, it could also catalyze the reaction of native lignin into monomers effectively without exogenous hydrogen. In addition, Ni-NDC-500 was recycled three times without an obvious reduction of the activity.