提高稀土氧化物催化酯化活性的新方法

A NEW METHOD OF INCREASING THE CATALYTIC ACTIVITY OF RARE EARTH OXIDES FOR ESTERIFICATION

有机羧酸与醇的酯化反应,原是用酸作催化剂,缺点甚多.近年来,非酸催化发展很快,其中用金属氧化物作为酯化催化剂已屡见报导,如ZnO,SnO等在工业上已用于催化合成增塑剂DOP(邻苯二甲酸二辛酯).关于稀土氧化物在酯化反应中的催化作用,曾有人对低沸点酸和醇的酯化用高温气相催化的方式作过一些研究。

The activation of the rare earth oxides as catalysts for esterification of 2-ethylhexanol with phathalic anhydride has been studied. The results show that the activity of the rare earth oxides can not be increased by calcination alone. But the rare earth oxides, such as Gd2O3, Ho2O3, Tm2O3 and Lu2O3, prepared from their corresponding HPMBP complexes upon calcination show higher activity than the light Ln,O3. During calcination, probably the rare earth oxide-HPMBP complexes release a large amount of gases which make the rare earth oxides expand and become porous as shown by the increasing of the relative surface area from 1-3m2/g to 11-15m2/g.