Engineering nano-ordered of Ni nanoparticles on KIT-6 for enhanced catalytic hydrogenation of nitrobenzene

Abstract

Catalytic hydrogenation of nitrobenzene by Ni nanoparticles on supports with high surface area is an economical and green route to produce aniline. To overcome the challenge of Ni nanoparticles blockage in the mesopores of KIT-6, a series of Ni-based KIT-6 catalysts were synthesized by designed engineering approaches. It was found that the engineering approaches were able to tune the nano-ordered of Ni nanoparticles and then remove the blockage on KIT-6, which significantly influence catalytic properties for nitrobenzene hydrogenation. The proposed engineering nano-ordered Ni nanoparticles blockage removal (ENBR) mechanism was systematically characterized. The characterization results confirmed that Ni dispersion, valence and metal surface area were adjusted by the ENBR process. The Ni particles located in the pore were not agglomerated, while the Ni particles located on the surface re-ordered to form larger particles and expose Ni particles blocked in the KIT-6 pores, which is the key factor for the remarkable enhancement of catalytic activity. Among all catalysts, with a specific surface area of 521.4 m2/g and Ni metal surface of 88.2 m2/g, Ni/KIT-6cal+red exhibited the best catalytic activity. This work was promising for the development of supported Ni catalysts to improve catalytic performance by engineering approaches.