KF/MgO催化甘油和碳酸二甲酯酯交换合成甘油碳酸酯

采用浸渍法制备KF/MgCO₃前体，经高温焙烧后获得了一系列KF/MgO固体碱催化剂，用于催化碳酸二甲酯（DMC）和甘油（GL）酯交换反应合成甘油碳酸酯（GC）。系统考察了KF负载量和焙烧温度对催化剂活性的影响，并通过X射线衍射、N₂吸脱附等温线、扫描电子显微镜和哈米特酸碱滴定等一系列技术对催化剂的结构性能进行了表征。结果表明，当KF负载量为20%（质量分数）时，经550℃焙烧所获得的20%KF/MgO-550催化剂活性最高。经过反应工艺条件的优化，当催化剂与甘油的相对质量分数为2%，DMC与GL的摩尔比为3∶1，75℃条件下反应1.5h后，GC收率可以达到96.8%。当20%KF/MgO-550催化剂重复使用3次之后，GC的收率由96.8%降低到67.3%，经再生处理后20%KF/MgO-550的催化活性可以恢复并且表现出更优异的稳定性。

KF/MgO catalyzed transesterification of glycerol and dimethyl carbonate to glycerol carbonate

A series of KF/MgO catalysts were prepared from the high temperature impregnated KF/MgCO₃ precursor, and then employed as solid base catalysts for the transesterification of dimethyl carbonate (DMC) and glycerol (GL) to glycerol carbonate (GC). The effects of KF content and calcination temperature on the catalytic performance were systematically investigated, and the structure of these catalysts were characterized by XRD, N₂ adsorption-desorption, SEM and Hammett acid-base titration. The 20%KF/MgO-550 sample calcinated at 550℃ with 20%KF loading was found to be the best catalyst for this reaction. The highest GC yield of 96.8% were obtained at the optimum reaction conditions of molar ratio of DMC to GL 3∶1, catalyst dosage of 2.0% (relative to GL mass), 75℃, and 1.5h reaction time. The GC yield over 20%KF/MgO-550 could drop from 96.8% to 67.3% in the third run, but the catalytic activity can be restored with more excellent stability after regeneration.