Tuning the Electron Density of Metal Nickel via Interfacial Electron Transfer in Ni/MCM-41 for Efficient and Selective Catalytic Hydrogenation of Halogenated Nitroarenes
Lei Huang, Feiying Tang, Fang Hao, Hao Zhao, Wenyuan Liu, Yang Lv, Pingle Liu, Wei Xiong, He’an Luo
Abstract
Catalytic hydrogenation of nitrocompound is an environment-benign strategy for the production of important aniline intermediates. Herein, MCM-41 was synthesized from sepiolite via an in situ self-assembled method, and the modified MCM-41 supported nickel-based catalysts were prepared and applied in halogenated nitrobenzene hydrogenation to halogenated aniline. As compared to Ni/MCM-41, the Sn- or La-modified MCM-41 supported nickel-based catalysts exhibited better catalytic performance. The electron transfer from Sn or La species to Ni led to a downshift in the d-band center of Ni, which was in favor of H desorption and hence promoted hydrogenation activity. It was found that chloronitrobenzene preferred the tilted adsorption orientation mode on the surface of Ni–Sn and Ni–La2O3 to flat adsorption orientation. Moreover, the C–Cl bond scission on Ni–Sn and Ni–La2O3 was thermodynamically unfavorable in comparison with pure-phased Ni, leading to higher selectivity to chloroaniline. Ni/LaMCM-41-NH2 gave the best catalytic performance of 100% conversion and 99.6% selectivity to m-chloroaniline.