Chinese Journal of Catalysis ›› 2021, Vol. 42 ›› Issue (5): 824-834.DOI: 10.1016/S1872-2067(20)63697-X

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MIL-53 (Al) derived single-atom Rh catalyst for the selective hydrogenation of m-chloronitrobenzene into m-chloroaniline

Weiyin Wanga,b, Lu Linb, Haifeng Qib,c, Wenxiu Caod, Zhi Lie, Shaohua Chenf, Xiaoxuan Zoua,#(), Tiehong Chenf, Nanfang Tangb, Weiyu Songe, Aiqin Wangb,g, Wenhao Luob,*()   

  1. aCollege of Chemistry, Xiangtan University, Xiangtan 411105, Hunan, China
    bCAS Key Laboratory of Science and Technology on Applied Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
    cUniversity of Chinese Academy of Sciences, Beijing 100049, China
    dCollege of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, Hunan, China
    eState Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
    fInstitute of New Catalytic Materials Science, School of Materials Science and Engineering, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Nankai University, Tianjin 300350, China
    gState Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
  • Received:2020-05-08 Accepted:2020-05-08 Online:2021-05-18 Published:2021-01-29
  • Contact: Xiaoxuan Zou,Wenhao Luo
  • About author:# E-mail: zouxiaoxuan@xtu.edu.cn
    * Tel: +86-411-84379738; Fax: +86-411-84685940; E-mail: w.luo@dicp.ac.cn;
    First author contact:

    Contributed equally to this work.

  • Supported by:
    Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020100);National Natural Science Foundation of China(21703238);National Natural Science Foundation of China(21690084);National Natural Science Foundation of China(21802134);Educational Commission of Hunan Province(19B463);Collaborative Innovation Center of Manganese-Zinc-Vanadium Industrial Technology(MXF202001);Research Startup Foundation of Jishou University(21)

Abstract:

The catalytic hydrogenation of halonitroarenes to haloanilines is a green and sustainable process for the production of key nitrogen-containing intermediates in fine chemical industry. Chemoselective hydrogenation poses a significant challenge, which requires the rational design of the catalysts with proper hydrogenation ability for nitro group and simultaneously preventing dehalogenation of halogen group. Herein, a highly effective Rh@Al2O3@C single-atom catalyst (SAC) was developed for the hydrogenation of m-chloronitrobenzene (m-CNB) to m-chloroaniline (m-CAN), through an in-situ grafting of metal during the assembly of MIL-53 (Al), followed by confined pyrolysis. Extensive characterizations reveal an exquisite structure of the Rh@Al2O3@C, containing atomically dispersed Rh sites onto Al2O3 confined by the amorphous carbon. The five-coordinated aluminum (AlV) species are essential for achieving the atomic dispersion of Rh atoms, providing the unsaturated coordinative sites for metal. Compared to the benchmark Rh/γ-Al2O3 and Rh/C nanocatalysts, the Rh@Al2O3@C SAC affords an excellent turnover frequency of 2317 molm-CNB·molRh-1·h-1, the highest value to date in heterogeneous catalyst systems for the hydrogenation of m-CNB at 313 K and 20 bar H2, together with a sustained selectivity to m-CAN (~98%) during five consecutive runs. The superior catalytic performance of the Rh@Al2O3@C is attributed to a proper modulation of electronic structure of hydrogenation metal by forming SAC, together with an enhanced accessibility of acid function sites.

Key words: Single-atom catalyst, Rhodium, Metal-organic framework, Hydrogenation, Chemoselectivity