The synthesis of 1,4-diazabicyclo (2.2.2) octane (DABCO) over modified ZSM-5 catalysts was carried out selectively in vapor phase with high conversion and yields. Pb, Zr and Cr-modified HZSM-5 zeolites with medium acidity gave high yields of DABCO. The acid sites of medium strength are found to be active for the selective synthesis of DABCO. The life of the catalyst was significantly improved by tuning various reaction parameters. The optimization of reaction parameters like mole ratio of the feed, weight hour space velocity, time on stream, effect of additives in the feed and the mechanism of selective formation of DABCO are described.

中文翻译：

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乙醇胺在修饰的五元硅沸石上分子间环化为1,4-二氮杂双环（2.2.2）辛烷

在改性的ZSM-5催化剂上选择性地在气相中进行1,4-二氮杂双环（2.2.2）辛烷（DABCO）的合成，具有很高的转化率和收率。具有中等酸性的Pb，Zr和Cr改性的HZSM-5沸石可提供高收率的DABCO。发现中等强度的酸位对于DABCO的选择性合成具有活性。通过调节各种反应参数，催化剂的寿命大大提高。描述了反应参数的优化，例如进料的摩尔比，重时空速，流上时间，进料中添加剂的影响以及选择性形成DABCO的机理。