新型泥煤生物炭基催化剂催化甘油酯交换合成碳酸甘油酯

A Novel Peat Biochar Supported Catalyst for the Transesterification Reaction of Glycerol to Glycerol Carbonate

以泥煤生物炭为原料,制备了一系列廉价、高效的固体碱复合催化剂,用于催化甘油和碳酸二甲酯进行酯交换反应制备碳酸甘油酯。通过扫描电子显微镜(SEM)、X射线能谱(EDS)、X射线衍射(XRD)、N2吸脱附(BET)、热重分析(TG)及Hammett指示法对催化剂进行表征。同时对催化剂的制备条件、催化反应条件及重复利用进行了分析。结果表明:催化剂30K/PB-600具有最优催化活性,当催化剂用量为5wt%、碳酸二甲酯/甘油摩尔比为4∶1、反应时间为90 min、反应温度为80℃时,甘油的转化率达到99.1%,碳酸甘油酯的产率达到95.7%;经过5次循环利用后,甘油的转化率为94.2%,碳酸甘油酯的产率为69.8%,产率下降的原因主要是由于K+的流失。

A series of low-cost and high-efficiency solid base heterogeneous catalysts were prepared by using peat as raw material, to promote the transesterification reaction of glycerol with dimethyl carbonate to produce glycerol carbonate（GC）. The chemical and structural properties of the catalysts were investigated by scanning electron microscope（SEM）, energy dispersive spectrometer（EDS）, X-ray diffraction（XRD）, N2 adsorption/desorption, thermogravimetric analysis（TG） and the Hammett indicator method. The catalyst preparation conditions, the catalytic reaction factors and the catalyst reusability were studied. The best performance was observed for the resulting 30 K/PB-600 catalyst, glycerol conversion of 99.1% and GC yield of 95.7% were achieved at catalyst load of 5 wt%, DMC/glycerol molar ratio of 4：1, reaction time of 90 min and reaction temperature of 80 oC. After 5 repeated used, the conversion of glycerol and the yield of GC attained 94.2% and 69.8%, respectively. It was found that the leaching of K＋ ions into reaction media led to the deactivation.