One-pot synthesis of porous silica-supported ultrafine Ni nanoparticles as efficient and stable catalyst for selective hydrogenation of benzophenone

Abstract

In this work, we report a silica-supported ultrafine Ni catalyst for the selective hydrogenation of benzophenone. This material was developed by a facile one-pot co-assembly syntheses strategy, using Ni(II) chelated alginate hydrogel as metal precursor and sacrificial template. Due to the highly active and uniformly dispersed Ni nanoparticles (NPs), 99.8% of benzophenone conversion was achieved. Remarkably, it also reached a 97.7% of selectivity for benzhydrol during benzophenone hydrogenation. Temperature-programmed desorption of ammonia (NH3-TPD) and Density Functional Theory (DFT) results reveal that the in-situ generated sodium carbonate (Na2CO3) derived from sodium alginate is essential in tuning the selectivity of benzhydrol: the existence of Na2CO3 reduces the surface acidity of catalyst and promotes the desorption of intermediate benzhydrol, preventing its further hydrogenolysis on the surface acidic sites of catalyst. Moreover, the supported Ni catalyst shows no significant loss of its activity during 20 times of recycling.