CaO/KIT-6固体碱催化剂的制备及其在酯交换反应中的催化性能

Preparation of CaO/KIT-6 solid base catalyst and its catalytic performance in transesterification

采用浸渍法将活性氧化钙颗粒负载在介孔二氧化硅(KIT-6)表面,制备了酯交换反应催化剂CaO/KIT-6,并研究了其在大豆油与甲醇酯交换制备生物柴油反应中的催化性能。通过X射线衍射(XRD)、X射线光电子能谱(XPS)、CO_(2)程序升温脱附(CO_(2)-TPD)等测试手段对催化剂进行表征。在酯交换反应中,当醇油物质的量比为12、反应温度为65℃、催化剂用量为8%、Ca/Si原子比为0.4、反应时间为2 h时,生物柴油转化率达到99.9%,CaO/KIT-6重复使用五次后催化活性仍保持在90%以上。与CaO及其他负载型催化剂相比,CaO/KIT-6催化剂在较低醇油物质的量之比、较短反应时间展现出更高的催化性能和良好的重复使用性。

CaO/KIT-6 was successfully prepared by loading activated calcium oxide particles on the surface of mesoporous silica(KIT-6)by post-synthesis method and tested for the transesterification of soybean oil with methanol.The catalyst was characterized by XRD,XPS,CO_(2)-TPD,N2 adsorption-desorption and TEM.It is found that when the molar ratio of methanol to oil is 12,the reaction temperature is 65℃,the addition of catalyst is 8%and the Ca/Si atomic ratio is 0.4,the conversion of soybean oil exceeds 99.9%at 2 h.After 5 cycles,the catalytic activity decreases slightly and the conversion is still up to 90%.Compared with CaO and other supported catalysts,CaO/KIT-6 catalyst exhibits higher catalytic performance and good reusability at lower methanol-to-oil molar ratio.