K_2CO_3对Na_2SiO_3+K_2CO_3/MgO催化性能的影响  

Effect of K_2CO_3 on catalyst performance of Na_2SiO_3+K_2CO_3/MgO

作　　者：付长亮 王少鹏 王宇飞 王利平 侯留成 FU Chang-liang;WANG Shao-peng;WANG Yu-fei;WANG Li-ping;HOU Liu-cheng(School of Chemical Engineering and Food Science,Zhengzhou Institute of Technology,Zhengzhou 450044,Henan Province,China;Haohua-Junhua Group Co.,Ltd.,Zhumadian 463002,Henan Province,China)

机构地区：[1]郑州工程技术学院化工食品学院,河南郑州450044 [2]昊华骏化集团有限公司,河南驻马店463002

出　　处：《化学工程》2019年第4期6-10,16,共6页Chemical Engineering(China)

基　　金：河南省科技开放合作计划(172106000067);河南省高校青年骨干教师资助计划(2013GGJS-297)

摘　　要：为提高催化剂的性能,在CO_2、甲醇和环氧丙烷合成碳酸二甲酯和碳酸丙烯酯反应的催化剂Na_2SiO_3/MgO中加入K_2CO_3,制得不同K_2CO_3质量分数的Na_2SiO_3-K_2CO_3/MgO催化剂。采用N_2吸附脱附、XRD、SEM和CO_2-TPD等表征方法对催化剂的孔结构、活性组分分布、表面形貌和活性位数量进行了测定;通过间歇反应釜对催化剂性能进行了评价;对反应条件进行了优化。当K_2CO_3的质量分数为17.5%时,催化剂具有较大的比表面积和孔容、较好的活性组分分布、较优的表面形貌、较多的催化活性碱位,并表现出较优的催化性能。在反应温度180℃、反应压力2.0 MPa、反应时间5 h、甲醇和环氧丙烷体积比为1.5∶1、搅拌转速200 r/min条件下,环氧丙烷的转化率达98.86%,碳酸二甲酯的选择性达54.67%,碳酸丙烯酯的选择性达30.89%,且催化剂的性能稳定。In order to improve the catalytic performance of Na2SiO3/MgO for synthesis of dimethyl carbonate and propylene carbonate from CO2,methanol and epoxy propane,a series of Na2SiO3-K2CO3/MgO catalysts with different K2CO3mass fraction were prepared.The pore structure,distribution of active ingredients,surface morphology,and number of active sites of catalyst were characterized by N2 adsorption desorption,XRD,SEM and CO2-TPD respectively.The performance of catalyst was evaluated and the reaction condition was optimized in a batch reactor.When the mass fraction of K2CO3 is 17.5%,the catalyst has a larger specific surface area and pore volume,better distribution of active components,better surface morphology,more catalytic activity base,and better catalytic performance.The optimum reaction condition are as follows:temperature 180℃,reaction pressure 2.0 MPa,reaction time 5 h,volume ratio of methanol to propylene oxide 1.5∶1,stirring speed 200 r/min.Under the optimum reaction condition,the conversion of epoxy propane is 98.86%,the selectivity of dimethyl carbonate is 54.67%,the selectivity of propylene carbonate is 30.89%.Furthermore,the catalyst displays outstanding catalytic stability.

关 键 词：碳酸钾 硅酸钠 二氧化碳 碳酸二甲酯 碳酸丙烯酯 

分 类 号：O643.38[理学—物理化学]