UV Light-Assisted Synthesis of Highly Efficient Pd-Based Catalyst over NiO for Hydrogenation of o-Chloronitrobenzene.

Supported Pd-based catalyst over active nickel oxide (NiO) was repared using the impregnation method companying with UV-light irradiation. Moreover, the catalytic performance of the obtained Pd-based catalysts was evaluated towards the hydrogenation of <italic>o</italic>-chloronitrobenzene (<italic>o</italic>-CNB). Observations indicate that the as-prepared UV-irradiated Pd/NiO catalyst with a mole fraction 0.2% (0.2%Pd/NiO) has higher activity and selectivity in the <italic>o</italic>-CNB hydrogenation. Especially, UV-light irradiation played a positive role in the improvement of catalytic activity of 0.2%Pd/NiO catalyst, exhibiting an excess 11-fold activity superiority in contrast with non-UV-irradiated 0.2%Pd/NiO catalyst. In addition, it was investigated that effects of varied factors (i.e., reaction time, temperature, <italic>o</italic>-CNB/Pd ratio, Pd loading, hydrogen pressure) on the selective hydrogenation of <italic>ο</italic>-CNB catalyzed by UV-irradiated 0.2%Pd/NiO catalyst. Under the reaction conditions of 60 °C, 0.5 h, 1 MPa H2 pressure, 100% conversion of <italic>o</italic>-CNB, and 81.1% <italic>o</italic>-CAN selectivity were obtained, even at high molar ratio (8000:1) of <italic>o</italic>-CNB to Pd. [ABSTRACT FROM AUTHOR]