Catalytic evaluation of tunable Ni nanoparticles embedded in organic functionalized 2D and 3D ordered mesoporous silicas from the hydrogenation of nitroarenes

The current drive to explore non-noble metal nanoparticles (NPs) utilized for the hydrogenation of nitroarenes encourages an extensive study of Ni NPs for their affordable price and magnetic properties. However, fabrication of stable and highly dispersed metal NPs against aggregation remains a great challenge. In this study, carboxylic acid modified siliceous supports with two distinctive pore architectures, so called 2D hexagonal channel SBA-15 and 3D cage-type SBA-16 are utilized for the controllable confinement growth of ultra-small Ni NPs. The catalytic activity of Ni-x/SBA-16C is found to be higher than that of Ni-x/SBA-15C and Ni-x/SiO₂ in the hydrogenation of nitroarenes to aminoarenes and greatly influenced by the Ni particle size, pore architectures, textural properties and Ni amounts. In addition, the magnetic properties allow facile and rapid recovery of the catalysts for reuse. This approach offers an affordable and easily separable catalyst for industrial applications.