Transition Metal Oxide-Modified Ir Nanoparticles Supported on SBA-15 Silica for Selective Hydrogenation of Substituted Nitroaromatics

Abstract

Modification of active metals with metal oxide modifiers has attracted considerable attention in heterogeneous catalysis due to their synergistic effect. However, a controllable synthesis of highly reactive and stable metal–metal oxide hybrid nanocatalysts is difficult. To solve this problem, presynthesized IrM (M = Fe, Co, and Ni) bimetallic nanoparticles were initially confined in the mesopores of SBA-15 and were then in situ transformed to Ir-MOx hybrids. The obtained Ir-MOx/SBA-15 nanocatalysts show superior activity and selectivity in the hydrogenation of substituted nitroaromatics to corresponding aromatic amines compared to Ir/SBA-15. Among these Ir-based catalysts, Ir-FeOx/SBA-15 exhibits the highest activity and selectivity and has a wider substrate scope due to the interaction between Ir and FeOx. Therefore, our research provides a way to design reactive and stable hydrogenation catalysts.