K_2O/SiO_2催化剂上正丙醇与碳酸二甲酯合成碳酸二丙酯

Synthesis of Dipropyl Carbonate from Dimethyl Carbonate and Propyl Alcohol on K_2O/SiO_2 Catalyst

采用正丙醇与碳酸二甲酯(DMC)酯交换合成碳酸二丙酯(DPC),筛选出催化性能和稳定性较好的KNO3固体碱催化剂,考察了KNO3负载量对催化剂酯交换性能的影响。实验结果表明,KNO3负载量(以K2O的质量分数计)为15%时,催化剂对酯交换反应的催化性能最好,在丙醇与DMC的物质的量比为2∶1、催化剂和反应物的质量比为0.01、反应时间为6 h的条件下,DMC的转化率和DPC的选择性分别达到85.85%和27.10%。CO2-程序升温脱附表征结果表明,K2O/Si O2催化剂上的弱碱中心是反应的催化活性中心,且碱量越大,催化性能越好。

Synthesis of dipropyl carbonate（DPC） from dimethyl carbonate（DMC） and propyl alcohol by transesterification was studied.A series of different loading quantity of KNO3 supported solid base catalysts were prepared and their catalytic activities were evaluated.Physicochemical properties of catalysts were characterized by means of XRD and CO2-TPD.The effects of preparation methods of supports and loading quantity of KNO3 as well as catalyst dosage,propyl alcohol/DMC mol ratio and reaction time on the activity of the catalyst were investigated.The results indicated that 15wt% K2O/SiO2 exhibited the highest activity for the synthesis of DPC.Under the optimal conditions：n（propyl alcohol）∶n（DMC）=2∶1,m（catalyst）∶m（reactant）=0.01, 100℃,6h,DMC conversion and DPC selectivity were 85.85% and 27.10%.The results indicate that the weak basic sites may be the active sites for the transesterification of propyl alcohol and DMC.