Enhancing the chemoselective hydrogenation of o-chloronitrobenzene over nanoporous Ni/NiAl3 catalysts

Halogenated aniline, which is usually produced by hydrogenation of halogenated nitrobenzene, is extensively employed in a variety of fields, including insecticides, medicines, pigments, and cosmetics. The design of cata-lysts to increase their selectivity in this application has become one of the research objectives. Herein, the nanoporous Ni/NiAl3 catalysts with a high specific surface area were designed and prepared by chemical dealloying of NiAl alloy, and the thickness of surface Ni could be easily adjusted. In the hydrogenation of o-chloronitrobenzene (o-CNB) to o-chloroaniline (o-CAN), the catalyst demonstrated great catalytic activity (TOF up to 155 h-1), the TOF is three times that of Raney Ni, and the selectivity to o-CAN remained over 99 % at complete conversion under 50 degrees C and 2 oa of H2. The findings demonstrate that at low surface Ni thickness, NiAl3 and Ni have a synergistic effect that alters the electron cloud density of the active site in a way that strengthens the adsorption of intermediates and can successfully modulate selectivity while maintaining high activity. These provide the foundation for designing high selectivity catalysts and preparing nanoporous intermetallic compound catalysts.