Unveiling the origin of enhanced catalytic performance of CePO4/Pt for selective hydrogenation of nitroarenes

Abstract

Supported catalysts are widely used in selective hydrogenation of nitroarenes, in which the choice of support has an important effect on the catalytic reaction rate and the selectivity of products. Herein, CePO4 as support to stabilize Pt nanoparticles for selective hydrogenation of nitroarenes is presented. The catalyst achieves a remarkable selectivity of aromatic amine production (>95 %) with a high turnover frequency (1476 h−1). Mechanistic studies reveals that the electronic structure of Pt is modulated by CePO4. In comparison to conventional CeO2/Pt catalyst, the Pt sites on CePO4 are negatively charged. Such configuration allows facile dissociation of H2 on Pt sites. Meanwhile, the potential-determining step (the formation of Ph-HNOH from Ph-HNO) on CePO4/Pt (0.73 eV) is a significantly lower than CeO2/Pt (1.15 eV), thereby favoring the pathway for aromatic amine production on Pt sites. Moreover, the CePO4 support has strong adsorption capacity of substrate, which plays a role as new active sites when adsorbed substrates are activated by active hydrogen species via hydrogen spillover. This work provides a new perspective into the development of selective nitroarenes conversion through the artful design of supported catalysts.