KOH/4A分子筛催化剂对环氧丙烷、二氧化碳和甲醇合成碳酸二甲酯反应的催化性能

 首次开发出对环氧丙烷、二氧化碳和甲醇合成碳酸二甲酯反应具有较高活性和稳定性的KOH/4A分子筛固体催化剂,考察了反应温度和催化剂活性组分KOH的负载量等因素对催化剂性能的影响. 在优化的实验条件下,环氧丙烷可以完全转化,碳酸二甲酯的收率为168%. 从实验结果推测,产物碳酸二甲酯是由环氧丙烷和二氧化碳加成生成碳酸丙烯酯,然后与甲醇发生酯交换反应生成的,甲醇对环氧丙烷和二氧化碳合成碳酸丙烯酯反应具有助催化作用.

Synthesis of Dimethyl Carbonate from Propylene Oxide, Carbon Dioxide and Methanol on KOH/4A Molecular Sieve Catalyst

The synthesis of dimethyl carbonate (DMC) from propylene oxide (PO), carbon dioxide and methanol on solid catalysts has been studied for the first time. A series of supported solid base catalysts were prepared by impregnation and their catalytic activity was evaluated. The KOH/4A molecular sieve was found to be the most effective catalyst for this reaction. The effects of the reaction temperature and KOH loading on the activity of the KOH/4A molecular sieve have been investigated. Under optimized conditions, PO could be converted completely and the yield of DMC reached 16.8%. It was proposed that DMC was formed from the transesterification of methanol with propylene carbonate which was formed from PO and carbon dioxide in this reaction. Methanol was favorable to the cycloaddition of PO with carbon dioxide.