Mechanistic insights into the catalytic reduction of nitrophenols on noble metal nanoparticles/N-doped carbon black composites

Abstract

Noble metal-based catalysts with rationally designed nanostructures have attracted considerable attention due to their excellent catalytic activity for important chemical reactions. It is highly desired to develop efficient nanostructured noble metal based catalysts and to understand the mechanism underlying their catalytic activities. Here, highly efficient nitrophenol reduction was achieved on Pd and Au nanoparticles decorated nitrogen-doped carbon black (NCB). Pd/NCB nanohybrids showed a better performance in the catalytic reduction reaction of 4-nitrophenol compared to Au/NCB catalysts. The improved performance of catalyst can be ascribed to the size of metal nanoparticles, good dispersity and interactions between noble metal nanoparticles and the support. Density functional theory (DFT) calculations reveal that stronger binding energy and greater charge transfer exist between Pd and NCB, implying that N dopant can boost the activity and stability of the hybrid catalysts through enhanced binding energy, more efficient electron transfer and rich active catalytic sites.