Relatively Electron-Rich Ni Nanoparticles Supported on α-Al<sub>2</sub>O<sub>3</sub> for High-Efficiency Hydrogenolysis of Lignin and Its Derivatives under Mild Conditions
Wei Jiang, Jing‐Pei Cao, Zu-Xing Huan, Xin Hu, Wen Tang, Chen-Xu Chen, Hongyan Wang, Zi‐Meng He, Xiao-Yan Zhao, Hongcun Bai
Abstract
Catalytic C–O bond hydrogenolysis is an essential route to produce sustainable chemicals and fuels from lignin and its derivatives. Herein, various Ni-based catalysts were successfully prepared and evaluated in the C–O bond hydrogenolysis of lignin-derived diphenyl ether (DPE) and benzyl phenyl ether (BPE). It is found that 10%Ni/α-Al 2 O 3 shows the highest activity for cleaving C–O bonds of DPE and BPE at low reaction temperatures and low H 2 pressures. Compared to 10%Ni/γ-Al 2 O 3 and 10%Ni/γ-Al 2 O 3 -2, 10%Ni/α-Al 2 O 3 exhibits a higher initial reaction rate for the conversion of DPE and BPE. Different characterizations reveal that the high activity of 10%Ni/α-Al 2 O 3 is ascribed to relatively electron-rich Ni metals, providing a large number of Ni–Ni bonds, which is mainly responsible for a rapid H 2 adsorption–activation–dissociation and for driving substrate hydrogenolysis. Furthermore, 10%Ni/α-Al 2 O 3 not only catalyzes C–O bond hydrogenolysis of other lignin derivatives but also achieves the depolymerization of real lignin to produce guaiacol with a high yield.