N,S-Co-doping Significantly Improves the Co–Nx Content of the Co-NSPC Catalyst and Enhances the Catalytic Performance for Selective Hydrogenation of Halogenated Nitrobenzenes

Abstract

Non-noble metals have attracted worldwide attention for the catalytic hydrogenation of halonitrobenzene due to their high activity, low price, and abundance on Earth. However, the construction of effective and stable non-noble-metal catalysts for the selective hydrogenation of halonitrobenzene to haloaniline by a simple method remains challenging. Herein, we report a facile one-pot method for the synthesis of N,S-co-doped mesoporous carbon-supported non-noble-metal catalysts through carbonization of a mixture of metallic precursors and 2-aminothiazole in molten ZnCl2. The prepared Co-NSPC catalyst showed excellent activity and selectivity with a turnover frequency of 84.4 h–1 in the hydrogenation of p-chloronitrobenzene to p-chloroaniline. Furthermore, Co–Nx was found to be the main active site for this reaction on the basis of characterization and experimental data, and the introduction of S promoted the formation of Co–Nx sites. Moreover, the Co-NSPC-800 catalyst can be reused at least four times and applied to the hydrogenation of 10 kinds of halogenated nitrobenzenes with excellent selectivity.