CaO@SiO2纳米固体碱的制备、表征及其大豆油酯交换反应催化性能

摘要

The CaO@SiO2 alkaline catalyst was prepared by sol-gel method that chooses polystyrene as hard template and P123 as soft template to control the microstructure. Furthermore, the prepared catalyst was applied to the transesterification of soybean and methanol. Also, the nano-solid based catalyst was characterized by X-ray diffraction ( XRD ) , scanning electron microscopy ( SEM ) , transmission electron microscopy ( TEM ) , CO2-TPD and N2 absorption-desorption ( BET ) . The results show that the catalyst possesses an ordered morphology and core-shell structure. In addition, the effect of the ratio of SiO2/CaO (mass ratio), reaction temperatures, catalyst dosages and the ratio of oil/methanol ( mol ratio) on the yield of biodiesel was examined. Under the best reaction condition, the yield of biodiesel can reach 95. 6%.%采用溶胶-凝胶法合成CaO@SiO2固体碱催化剂，以聚苯乙烯有机聚合物为硬模板剂和以P123为软模板剂对CaO的微观形貌进行调控。并将其应用于大豆油与甲醇的酯交换制备生物柴油的反应体系中。通过对CaO@SiO2纳米固体碱催化剂进行X射线衍射( XRD)、扫描电子显微镜( SEM)、透射电镜( TEM)、CO2-TPD及N2的吸附-脱附( BET)表征发现，不仅制备得到了形貌归整的纳米固体颗粒，而且得到了CaO包裹在SiO2表面的核壳结构。进一步考察了不同的硅钙质量比、反应温度、催化剂的用量以及油醇物质的量比对生物柴油收率的影响，生物柴油的收率最高可以达到95.6%。