Surface Engineering of ZnO with 2-Methylimidazole for Highly Dispersed Au–Pt Nanoparticles and Enhanced Hydrogenation Catalysis

The development of highly dispersed supported noble-metal catalysts is crucial for maximizing atomic utilization and enhancing catalytic performance. This work demonstrates a highly efficient Au–Pt bimetallic catalyst supported on 2-methylimidazole-modified ZnO (N-ZnO) for the chemoselective hydrogenation of nitroarenes. The modification creates strong anchoring sites for metal precursors, which, as confirmed by DFT calculations, effectively suppress metal aggregation and yield highly dispersed nanoparticles with an average size of 2.9 nm. The resulting Au–Pt/N-ZnO catalyst exhibits exceptional performance in the hydrogenation of p-chloronitrobenzene under mild conditions (50 °C and 0.5 MPa H2), achieving >99% conversion and 98.6% selectivity to p-chloroaniline, significantly outperforming its monometallic counterparts due to the synergistic effect. The catalyst also exhibited excellent recyclability and broad substrate applicability for various substituted nitroarenes. This work provides an effective strategy for fabricating highly efficient supported bimetallic catalysts through the organic ligand-mediated surface modification of metal oxide supports.