Selectivity control of Pt/SiC catalysts for photothermocatalytic hydrogenation of 3-nitrostyrene

Abstract

Chemoselective hydrogenation of 3-nitrostyrene to 3-aminostyrene is a challenge because there are two easily reducible functional groups in one molecule. Bimetallic catalysts usually exhibit enhanced selectivity for the selective hydrogenation, but require higher reaction temperatures (~100 °C). Herein, we report that SiC-supported Pt-Fe catalyst can efficiently catalyze the selective hydrogenation of a variety of substituted nitroarenes to corresponding amines under mild conditions (20 °C, 1 atm of H2, white LED light irradiation and triethylamine (TEA) as sacrificial electron donor). For the hydrogenation of 3-nitrostyrene to 3-aminostyrene, the turnover frequency can be as high as 2366 h−1. The characterization results suggest that both the electronic structure of Pt and the adsorption mode of 3-nitrostyrene have changed after Fe incorporation. The iron species and TEA jointly consumed the holes on the SiC support, which favored the activation of CC bonds, thus increased the selectivity of 3-aminostyrene evidently. These results are helpful for designing Pt-based catalysts with excellent chemoselectivity.