ZnO催化尿素和丙二醇合成碳酸丙烯酯的反应研究

尿素和丙二醇合成碳酸丙烯酯(PC)在热力学上是可进行的。根据ZnO对尿素和丙二醇的催化反应性能，讨论了合成PC的反应历程。结果表明，该反应是分步进行的，首先尿素分解生成氨气和异氰酸，异氰酸与ZnO作用形成异氰酸物种，在丙二醇的作用下生成中间产物羟丙基氨基甲酸酯(HPC)，然后由HPC脱氨气生成PC。 ZnO在尿素分解和HPC脱氨气转化为PC的反应过程中起催化作用。

Synthesis of propylene carbonate from urea and propylene glycol using ZnO catalyst

The thermodynamical stuty indicates that the synthesis of propylene carbonate (PC) from urea and propylene glycol is possible. The reaction process for synthesis of PC was investigated using ZnO catalyst. It was a stepwise process. At first, urea decomposed into isocyanic acid, which interacted with ZnO to form a relatively steady isocyanate species. Then propylene glycol reacted with isocyanate species to form hydroxypropyl carbamate (HPC), and the HPC lost ammonia to form PC. The catalysis of ZnO was striking in urea decomposition and the transformation of HPC to PC.