非晶态Ni-P合金上硝基苯催化加氢制苯胺的本征动力学  

Intrinsic kinetics of catalytic hydrogenation of nitrobenzene to aniline on Ni-P amorphous alloy catalyst

作　　者：蒋月秀[1] 刘瑞雯[1] 秦祖赠[1,2] 纪红兵[1,2] 邓小波[1] 

机构地区：[1]广西大学化学化工学院,广西南宁530004 [2]中山大学化学化工学院,广东广州510275

出　　处：《工业催化》2014年第2期95-101,共7页Industrial Catalysis

基　　金：国家自然科学基金(21006013)资助项目

摘　　要：Ni-P非晶态合金催化剂因其晶体结构的特殊,具有较好的催化活性.以硝基苯液相催化加氢合成苯胺为目标反应,运用Matlab软件并借助Levenberg-Marquardt算法估计反应动力学模型的参数,根据参数估计结果筛选动力学机理模型,对新型Ni-P非晶态合金催化剂的本征动力学进行研究,为催化剂的进一步开发和反应器设计提供理论依据.结果表明,Ni-P非晶态合金催化剂的颗粒较小,过程内扩散的影响可以忽略不计,当搅拌速率达到600 r·min-1时,反应过程的外扩散影响也可忽略.在（373.15～403.15）K、氢压1.0 MPa、非晶态Ni-P催化剂质量0.2 g、硝基苯质量2.0g和无水乙醇质量8.0g条件下,硝基苯分子不吸附,硝基苯分子与解离吸附的氢原子在催化剂表面反应,苯胺脱附为硝基苯加氢合成苯胺反应的速率控制步骤,本征动力学模型为：rj=kcA/1＋√bH2αH2PH2,表面反应的指前因子为1.08×105 min-1,活化能为51.81 kJ·mol-1,氢气吸附热为64.12 kJ·mo1-1.Ni-P amorphous alloy catalyst shows excellent catalytic activity due to its special crystal structures.In this paper,the values of reaction kinetics parameters for the catalytic hydrogenation of nitrobenzene to aniline were estimated by applying Matlab software and Levenberg-Marquardt method.According to the results of estimated parameters,the most appropriate kinetics mechanism model was selected.The study of the intrinsic kinetics of Ni-P amorphous alloy catalyst could provide the theoretical foundation for the further development of the catalysts and the design of the reactors.The results showed that the internal diffusion effect in the reaction process was negligible due to the small particles of Ni-P amorphous alloy catalyst and the external diffusion effect was also negligible when the stirring speed was 600 r · min-1 Under the condition of reaction temperature （373.15-403.15） K,hydrogen pressure 1.0 MPa,amorphous Ni-P catalyst dosage 0.2 g,nitrobenzene amount 2.0 g,and absolute alcohol amount 8.0 g,the reaction between dissociative adsorption hydrogen and nitrobenzene which was not adsorbed was carried out on the catalyst surface,and the desorption of aniline was the rate-determining step in the hydrogenation of nitrobenzene to aniline.The kinetic equation was rj =kcA/1＋√bH2αH2PH2,The pre-exponential factor was 1.08 × 105 min-1.The activation energy of the reaction was 51.81 kJ · mol-1.The adsorption heat of hydrogen was 64.12 kJ · mol-1.

关 键 词：催化化学 硝基苯 催化加氢 本征动力学 非晶体Ni-P合金 

分 类 号：O643.1[理学—物理化学] TQ426.94[理学—化学]