SCI和EI收录∣中国化工学会会刊

›› 2017, Vol. 25 ›› Issue (3): 306-312.DOI: 10.1016/j.cjche.2016.08.005

• Catalysis, Kinetics and Reaction Engineering • 上一篇    下一篇

High halogenated nitrobenzene hydrogenation selectivity over nano Ir particles

Lei Ma, Jianguo Wang, Hanbing Wang, Qunfeng Zhang, Chunshan Lu, Xiaobo He, Xiaonian Li   

  1. Industrial Catalysis Institute of Zhejiang University of Technology, State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, Hangzhou 310032, China
  • 收稿日期:2016-03-20 修回日期:2016-08-02 出版日期:2017-03-28 发布日期:2017-04-15
  • 通讯作者: JianguoWang, Xiaonian Li
  • 基金资助:
    Supported by the National Natural Science Foundation of China (Nos. 21473159 and 91334013).

High halogenated nitrobenzene hydrogenation selectivity over nano Ir particles

Lei Ma, JianguoWang, HanbingWang, Qunfeng Zhang, Chunshan Lu, Xiaobo He, Xiaonian Li   

  1. Industrial Catalysis Institute of Zhejiang University of Technology, State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, Hangzhou 310032, China
  • Received:2016-03-20 Revised:2016-08-02 Online:2017-03-28 Published:2017-04-15
  • Supported by:
    Supported by the National Natural Science Foundation of China (Nos. 21473159 and 91334013).

摘要: The selective hydrogenation of halogenated nitrobenzene over noblemetal catalysts (Pd, Pt, and Ir) has attracted much attention owing to its high efficiency and environmental friendliness. However, the effect of size on the catalytic performance varies among different metal catalysts. In this study, sub-nano (<3 nm) Ir and Pd particles were prepared, and their catalytic properties for hydrogenation of halogenated nitrobenzene were evaluated. Results show that high selectivity (>99%) was achieved over small Ir nanoparticles, in which the selectivity over the Pd with same size was much lower than that on Ir nanoparticles. Meanwhile, Ir and Pd have different hydrogen consumption rates and reaction rates. Density functional theory calculations showed that p-chloronitrobenzene (CNB) has different adsorption properties on Ir and Pd. The distance between oxygen (cholorine) and Ir is much shorter (longer) than that between oxygen and Pd. The reaction barriers of dechlorination of p-CNB and p-chloroaniline over different Irmodels aremuch larger than those on Pd. Especially, lower coordination of Ir leads to larger barriers of dechlorination reaction. These theoretical results explain the difference between Ir and Pd on hydrogenation of halogenated nitrobenzene.

关键词: Halogenated nitrobenzene, Selective hydrogenation, Sub-nano Ir, Density functional

Abstract: The selective hydrogenation of halogenated nitrobenzene over noblemetal catalysts (Pd, Pt, and Ir) has attracted much attention owing to its high efficiency and environmental friendliness. However, the effect of size on the catalytic performance varies among different metal catalysts. In this study, sub-nano (<3 nm) Ir and Pd particles were prepared, and their catalytic properties for hydrogenation of halogenated nitrobenzene were evaluated. Results show that high selectivity (>99%) was achieved over small Ir nanoparticles, in which the selectivity over the Pd with same size was much lower than that on Ir nanoparticles. Meanwhile, Ir and Pd have different hydrogen consumption rates and reaction rates. Density functional theory calculations showed that p-chloronitrobenzene (CNB) has different adsorption properties on Ir and Pd. The distance between oxygen (cholorine) and Ir is much shorter (longer) than that between oxygen and Pd. The reaction barriers of dechlorination of p-CNB and p-chloroaniline over different Irmodels aremuch larger than those on Pd. Especially, lower coordination of Ir leads to larger barriers of dechlorination reaction. These theoretical results explain the difference between Ir and Pd on hydrogenation of halogenated nitrobenzene.

Key words: Halogenated nitrobenzene, Selective hydrogenation, Sub-nano Ir, Density functional