Photothermal conversion enhances selective hydrogenation over MOF-derived Cu–MoO2 interfaces under ambient conditions†

Abstract

The selective hydrogenation of nitroaromatic compounds to produce phenylamines plays a crucial role in various industrial processes. Here, we introduce a Cu–MoO₂@C catalyst, which is synthesized by pyrolyzing a polyoxometalate-based metal–organic framework (POMOF), exhibiting remarkable catalytic efficiency in the selective hydrogenation of nitroaromatics. Specifically, nearly 100% conversion and 97% selectivity in hydrogenation of 4-nitrostyrene (4-NS) to 4-aminostyrene (4-AS) were achieved over the Cu–MoO₂@C catalyst under light irradiation. This promoted yield of 4-AS is ascribed to the plasmonic photothermal effect of Cu nanoparticles (NPs), which facilitate efficient photothermal conversion, as well as the strong electronic interactions at Cu/MoO₂ interfaces, which facilitate the selective reduction of the NO bond while minimizing the reduction of the CC bond. Furthermore, the Cu–MoO₂@C catalyst demonstrates outstanding stability, maintaining high catalytic activity over eight cycles with minimal performance degradation. Its versatility was evidenced by the effective hydrogenation of a variety of nitroaromatic substrates containing different reducible functional groups. This study underscores the potential of Cu–MoO₂@C as an efficient, stable, and adaptable catalyst for the selective hydrogenation of nitroaromatic compounds, presenting a promising solution for industrial applications.