Ultrathin 2D NiCo-MOF bimetallic nanosheets as single-atom catalysts for chemoselective hydrogenation of nitroarenes

Abstract

Exploration of non-noble-metal-based catalysts with high catalytic activity and selectivity is significant for driving innovation in green chemistry and technology. Herein, we report a facile synthesis of two-dimensional (2D) NiCo-MOF bimetallic nanosheets, which exhibited excellent catalytic performance, in terms of high conversion rate (99.9%), high selectivity (98.0–99.9%), rapid reduction kinetics (1–10 min) and mild reaction conditions (room temperature), for the catalytic hydrogenation of various nitroarenes and aldehyde compounds. These excellent catalytic performances were distinctly superior to those of other catalysts, and they can stem from the unique structure of the 2D NiCo-MOF bimetallic catalyst. The bimetallic system could effectively enhance the reaction selectivity with considerable reactivity, and the maximized utilization of the dispersed catalytic sites in the 2D MOF-based single-atom catalytic system could efficiently enhance the overall catalytic activity. Thus, the co-action of the synergistic effect of the bimetallic system and the maximal utilization of the catalytic sites endowed the 2D bimetallic MOF catalytic system with rapid, efficient, and highly selective catalysis under extremely gentle conditions. The reaction mechanism of the hydrogenation was investigated by density functional theory calculations and X-ray photoelectron spectroscopy. Our study provides an appealing strategy for constructing highly efficient and selective catalysts and demonstrates the significance of 2D ultrathin MOF nanosheets in the catalysis field.