SELECTIVE SYNTHESIS OF DIMETHYLAMINE OVER RARE EARTH MODIFIED MORDENITES

研究了稀土（Ｃｅ、Ｇｄ和Ｙ）改性丝光沸石用作甲醇胺化催化剂在常压固定床反应器中选择性合成二甲胺的催化性能。结果表明，稀土阳离子交换改性能改善丝光沸石的催化性能。丝光沸石经０．１ｍｏｌ／ＬＣｅ４＋溶液处理，与膨润土成型，再于６００℃下焙烧２～３ｈ，这样制得的催化剂在常压４００℃时的活性及二甲胺选择性分别达到９９．８％和５０．３％。此外，详细探讨了不同改性及制备条件对催化剂催化性能及机械强度的影响。

SELECTIVE SYNTHESIS OF DIMETHYLAMINE OVER RARE EARTH MODIFIED MORDENITES

The selective synthesis of dimethylamine from ammonia and methanol over the rare earth modified mordenites in a fixed bed reactor was studied. A mordenite, NaM, was modified by different rare earth elements, such as Ce, Gd and Y, with cation-exchange method. The experimental results show that various modified mordenites have better catalytic properties compared to the unmodified mordenites. The Ce4+ modified mordenite, prepared by treating with a solution of 0.1 mol/L Ce4+ and calcining at 600oC for 2-3h after moulded with a binder (bentonite), exhibits both high conversion of methanol and selectivity to DMA, up to 99.8% and 50.3%, respectively, at 400oC and under ambient pressure, and has an improved stability against coking.