Ni/SiO_2催化剂上间二硝基苯液相加氢制间苯二胺  

Liquid-Phase Hydrogenation of m-Dinitrobenzene to m-Phenylenediamine over Silica-Supported Nickel Catalyst

作　　者：刘迎新[1] 陈吉祥[2] 张继炎[2] 

机构地区：[1]天津大学化工学院,天津300072 [2]天津大学化工学院催化科学与工程系,天津300072

出　　处：《催化学报》2003年第3期224-228,共5页

摘　　要：将等体积浸渍法制备的Ni SiO2 催化剂应用于间二硝基苯液相加氢制间苯二胺反应中 ,通过BET ,XRD ,TEM ,TPR ,H2 TPD和活性评价等方法对催化剂的物化性质及催化性能进行了研究 ,考察了镍含量对催化剂活性的影响 .结果表明 ,Ni SiO2 催化剂不仅具有很高的催化活性 ,而且对间苯二胺表现出很高的选择性 ;催化剂的活性随着镍含量的不同而有所变化 .当w(Ni) <2 0 %时 ,随着镍负载量的增加 ,催化剂的活性逐渐升高 ,而当w(Ni) ≥ 2 0 %时 ,催化剂的活性和选择性基本趋于稳定 .m-Phenylenediamine is an important organic chemical raw material and intermediate. The catalytic hydrogenation technology for m-dinitrobenzene in liquid phase can be an attractive and elegant routine for production of m-phenylenediamine. A series of silica-supported nickel catalyst samples with a wide range of nickel contents ( w(Ni)=10%～50%), prepared by incipient impregnation method, were used in hydrogenation of m-dinitrobenzene to m-phenylenediamine. Based on the experimental results of nitrogen adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), temperature-programmed desorption of hydrogen (H_2-TPD) and activity evaluation, the physico-chemical properties and catalytic performance of the catalyst were investigated. The silica-supported nickel catalyst exhibited very high catalytic activity and selectivity for m-phenylenediamine, suggesting that this kind of catalyst is a promising catalyst for the synthesis of m-phenylenediamine. After reaction for 6 h, the conversion of m-dinitrobenzene increased from 94% to 97%, and the selectivity for m-phenylenediamine correspondingly changed from 96% to 97.7%, with w(Ni) increasing from 10% to 20%, while the activity and the selectivity of the samples with w(Ni)≥20% almost reached a plateau. The nickel content obviously affected the physico-chemical and reductive properties of the catalyst. The BET surface area of the catalyst samples decreased with the increase in nickel content, while the nickel particle size increased owing to the gather of nickel on the catalyst surface. The results of TPR and H_2-TPD characterization showed that the reduction temperature, the amount of free state NiO and the active surface area of the catalyst increased, and the adsorption of hydrogen on the catalyst was strengthened.

关 键 词：Ni/SiO2催化剂 液相加氢 镍 二氧化硅 负载型催化剂 间二硝基苯 间苯二胺 

分 类 号：O643.3[理学—物理化学]