Stabilizing Ag/CuO Core/Shell Nanotriangles for Selective Hydrogenation Reaction

Abstract

Designing high-performance catalysts for selective hydrogenation of nitrostyrolene compounds is challenging. Herein, we present an innovative approach to the creation of reusable CuO-based non-noble metal nanomaterials, which serve as highly efficient catalysts. We describe the use of Ag nanotriangles as a support to in situ grow CuO to form a unique core/shell structure, creating Ag/CuO core/shell nanotriangles catalysts. The well-defined catalyst exhibits excellent activity and selectivity toward the hydrogenation of 4-nitrostyrene to 4-aminostyrene under ambient temperature and atmospheric pressure conditions. The conversion rate and selectivity reach 99%, respectively, with a turnover frequency of 957 h^–1. After five cycles of experiments, we found that the selectivity did not significantly decrease, indicating the good stability of the catalysts. In situ Fourier transform infrared spectroscopy confirms the preferential adsorption of Ag/CuO core/shell nanotriangles catalysts for -NO₂. As there are certain oxygen vacancies on the surface of copper oxide, it has a strong adsorption capacity for the nitro group in p-nitrostyrene molecules. This brings the nitro group closer to the active center of the catalyst, thereby facilitating the hydrogenation reaction to occur preferentially on the nitro group. The strategy opens a new approach for designing effective catalysts to meet the requirements and applications for selective hydrogenation reaction.