Effects of the Supports on Activity of Supported Nickel Catalysts for Hydrogenation of m-Dinitrobenzene to m-Phenylenediamine  

作　　者：刘迎新 陈吉祥 张继炎 

机构地区：[1]College of Pharmaceuitcal Science, Zhejiang University of Technology,Hangzhou 310032, China [2]School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China

出　　处：《Chinese Journal of Chemical Engineering》2007年第1期63-67,共5页中国化学工程学报（英文版）

摘　　要：The hydrogenation of m-dinitrobenzene to m-phenylenediamine in liquid phase was studied with the nickel catalysts supported on SiO2, TiO2, γ-Al2O3, MgO and diatomite carders. Based on the experiments of X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, temperature-programmed reduction （TPR）, temperature-programmed desorption of hydrogen （H2-TPD） and activity evaluation, the physico-chemical and catalytic properties of the catalysts were investigated. Among the catalysts tested, the SiO2 supported nickel catalyst showed the highest activity and selectivity towards m-phenylenediamine, over which 97.3% m-dinitrobenzene conversion and 95.1% m-phenylenediamine yield were obtained at 373K under hydrogen pressure of 2.6MPa after reaction for 6 h when using ethanol as solvent. Although TiO2 and diatomite supported nickel catalysts also presented high activity, they had lower selectivity towards m-phenylenediamine. As for γ-Al2O3 and MgO supported catalysts were almost inactive for the object reaction. It was shown that both the activity and selectivity of the catalysts were strongly depended on the interaction between nickel and the support. The higher activities of Ni/SiO2, Ni/TiO2 and Ni/diatomite could be attributed to the weaker metal-support interaction, on which Ni species presented as crystallized Ni metal particles. On the other hand, there existed strong metal-support interaction in Ni/MgO and Ni γ-Al2O3, which causes these catalysts more difficult to be reduced and the availability of Ni active sites decreased, resulting in their low catalytic activity.The hydrogenation of m-dinitrobenzene to m-phenylenediamine in liquid phase was studied with the nickel catalysts supported on SiO2, TiO2, γ-Al2O3, MgO and diatomite carriers. Based on the experiments of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), temperature-programmed desorption of hydrogen (H2-TPD) and activity evaluation, the physico-chemical and catalytic properties of the catalysts were investigated. Among the catalysts tested, the SiO2 supported nickel catalyst showed the highest activity and selectivity towards m-phenylenediamine, over which 97.3% m-dinitrobenzene con-version and 95.1% m-phenylenediamine yield were obtained at 373K under hydrogen pressure of 2.6MPa after re-action for 6 h when using ethanol as solvent. Although TiO2 and diatomite supported nickel catalysts also presented high activity, they had lower selectivity towards m-phenylenediamine. As for γ-Al2O3 and MgO supported catalysts were almost inactive for the object reaction. It was shown that both the activity and selectivity of the catalysts were strongly depended on the interaction between nickel and the support. The higher activities of Ni/SiO2, Ni/TiO2 and Ni/diatomite could be attributed to the weaker metal-support interaction, on which Ni species presented as crystal-lized Ni metal particles. On the other hand, there existed strong metal-support interaction in Ni/MgO and Ni/γ-Al2O3, which causes these catalysts more difficult to be reduced and the availability of Ni active sites de-creased, resulting in their low catalytic activity.

关 键 词：HYDROGENATION M-PHENYLENEDIAMINE M-DINITROBENZENE supported nickel catalyst metal-support interaction 

分 类 号：O643.36[理学—物理化学]