Tuning the Electron Density of Metal Nickel via Interfacial Electron Transfer in Ni/MCM-41 for Efficient and Selective Catalytic Hydrogenation of Halogenated Nitroarenes

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.