| 刘文明,李凤仪.稀土氯化物催化丙烯直接环氧化反应研究[J].分子催化,2001,(1):25-28 |
| 稀土氯化物催化丙烯直接环氧化反应研究 |
| Epoxidation of Propylene with O_2 Catalyzed by Rare Earth Chlorides |
| 修订日期：2000-06-09 |
| DOI： |
| 中文关键词: 氯化稀土 催化剂 丙烯 环氧化反应 环氧丙烷 催化作用机制 |
| 英文关键词:Rare earth chloride,Propylene,Oxygen,Catalyst,Epoxidation |
| 基金项目: |
| 刘文明 李凤仪 |
| [1]华南理工大学化工系，广东广州510640 [2]南昌大学应用化学研究所，江西南昌330047 |
| 摘要点击次数: 1161 |
| 全文下载次数: 13 |
| 中文摘要: |
| 以氯化稀土为催化剂，以锌粉为还原剂，对不同羧酸和溶剂条件下的丙烯直接用氧气环氧化进行了研究，并对它的催化反应机理进行了初步探讨，实验结果表明，氯化稀土中有EuCl3对丙烯直接环氧化起催化作用，并且要在锌粉和羧酸共同存在下才有效，所用羧酸中丙酸的效果最佳，使用有机溶剂比不用溶剂效果更好，但不能用碱性物质作为反应体系的溶剂。反应气压力越高越有利于 环氧丙烷（PO）的生成，但反应温度不宜过高，在EuCl3、锌粉、羧酸催化体系中，EuCl3起电子传递的桥梁作用，锌粉提供电子,羧酸提供质子，推测的反应机理与实验结果吻合。 |
| 英文摘要: |
| The formation of propylene oxide from propylene by direct epoxidation with O 2 has been studied over rare earth chloride catalysts with different carboxylic acids and solvents, and a preliminary discussion on the mechanism of this reaction has been given. Significant PO formation was observed only over EuCl 3 catalyst and in the presence of zinc powder and carboxylic acids. As to the carboxylic acids, propanoic acid is the best for epoxidation of propylene. The yields of the epoxide were higher than those without solvents, but basic substance was not suitable as solvent. The higher the pressure used, the more TON obtained. However high reaction temperature was not suitable for epoxidation. In the catalytic system of EuCl 3, zinc powder and carboxylic acids, EuCl 3 plays a role in transferring electron; zinc powder is the e - donor and carboxylic acids is the H + donor. The mechanism given is consistent with the results of the experiments. |
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