四水硫酸铈催化合成丁二酸二乙酯及催化剂失活原因分析

以Ce(SO4)2.4H2O为催化剂合成了丁二酸二乙酯,考察了影响反应的条件并获得最优的试验结果。并从理论上分析了催化剂失活的原因,认为四水硫酸铈的催化活性与表面质子酸性质有关。在反应过程中,催化剂发生结晶水的丢失,铈离子价态的降低及晶体结构的变化,使催化剂的质子酸量降低,质子酸强度减弱,从而导致催化剂的催化活性下降。

Deactivation of Ce(SO4)2·4H2O catalyst for synthesis of diethyl succinate

In this paper,Ce(SO4)2.4H2O was applied to esterification of succinic acid with ethyl alcohol.Reaction conditions were studied and the optimum condition was obtained.But the catalytic activity of the catalyst for esterification reduced to a great extent when Ce(SO4)2.4H2O was used repeatedly.The causes for the deactivation of catalyst were discussed by the theoretic analysis.It was found that the catalytic activity of Ce(SO4)2.4H2O catalyst resulted from the sites of Br?nsted acid.In the process of reaction,the amount of Br?nsted acid decreased and its intensity became weaker because of the loss of crystal water,the reduction of Ce4 and the variation of crystal structure,so the catalytic activity of catalyst decreased.