摘要
以3种不同孔径-γAl2O3为载体制备固载化AlCl3/-γAl2O3催化剂,考察了各催化剂在苯与苄基氯烷基化合成二苯基甲烷反应中的催化活性及产物选择性,并同纯AlCl3催化剂进行了比较.采用气相色谱法分析反应产物组成,获得了不同催化剂在不同反应温度下的烷基化反应试验数据,在确定反应动力学方程及消除外扩散影响前提下,计算了反应速率常数、反应表观活化能和扩散系数.结果表明,同均相纯AlCl3催化剂相比,在固载化AlCl3催化剂上反应速率较低而且存在诱导期,且载体孔径越小,该现象越明显.动力学分析认为产生这一现象的主要原因是载体对反应内扩散的影响.
The catalyst of AlCl3 immobilized on γ-AlCl3 with different pores was prepared and tested in the benzylation reaction of benzene with benzyl chloride to form diphenylmethane. Conventional homogeneous pure AlCl3 was also included for comparison especially on temperature. The experimental data of forming diphenylmethane for different reaction temperature and catalyst were gained by gas chromatography. The kinetics model of the reaction, in which internal diffusion factors were considered, was established. Then the parameters of diphenylmethane apparent formation rate constant, apparent activation energy and diffusion coefficient were obtained in a liquid-solid reaction system. The results indicate that the immobilized AlCl3 catalyst was found to be more selective but less active compared to pure AlCl3 due to its pore diffusion resistance. With the decrease of the pore diameter of the supports, the diffusion coefficient of the reaction decreases sharply. The internal diffusion resistance plays an important role in the activity of benzylation reaction of benzene with benzyl chloride to form diphenylmethane over the immobilized AlCl3 catalysts.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2008年第2期168-172,共5页
Journal of Dalian University of Technology
基金
大连理工大学"九八五"重点资助项目(200488Q91)
大连理工大学青年教师培养基金资助项目(2003893212)
