合成云母蒙脱石及其交联物在乙醇氨化反应中的催化行为

Catalytic Behaviour of Synthetic SMM and Pillared SMM in the Animation of Ethanol

用水热法合成了云母蒙脱石,并与羟基铝齐聚物交联,DTA和IR结果表明,由于柱的引进,高温焙烧时层内八面体上羟基脱除变得较为容易。由NH_3-TPD和吡啶吸附测得的表面酸性表明Al-CLS具有较SMM更多的弱酸和强酸中心。催化剂上弱酸中心有利于醇的脱水,而吸附在强酸中心上的NH_3有利于醇的胺化。

Synthetic mica-montmoriilonite (SMM) was synthesized by using the hydrothertnal method. Pillared synthetic dioctahedral clays(Al-CLS) were prepared by crosslinking SMM with hydroxyl aluminium oligomer between the layers. The results obtained by DTA and IR indicate that the dehydroxylation of octahedral hydroxyl group is easier at a high temperature calcination because of pillar introduced. The surface acidity of SMM and Al-CLS measured by NH3-TPD and pyridine adsorption showed that Al-CLS presents even more sites of weaker and stronger acid than SMM. The dehydration-amination of ethanol with ammonia was studied over SMM and Al-CLS at 400℃ under ambient pressure. It is found that the weak acid sites on the surface favour the dehydration of ethanol and the NH3 molecular adsorpted on the strong acid sites favour the amination of ethanol. The results from NH3-TPD, C:H5OH-TPD and estimation test showed that the reaction between NH3 adsorpted on the strong acid sites and gas state C2H5OH perhaps occur in the amination of ethanol.