La和KF改性Y型分子筛催化丙烯醛二乙缩醛/氨合成吡啶和3-甲基吡啶

摘要

在连续流动固定床反应中,以丙烯醛二乙缩醛、水和氨为原料,合成了吡啶和3-甲基吡啶.比较了La-和KF-改性Y型分子筛的活性大小,考察了La负载量和改性方式、KF负载量及KF/Y的焙烧温度的影响.研究结果表明,与纯Y型分子筛相比,La和KF改性Y型分子筛均能增强催化活性.采用浸渍法和La负载量为1％(质量分数)时,吡啶和3-甲基吡啶总收率达到最高值;与浸渍法相比,采用离子交换法制备La-Y的活性更好.采用浸渍法、KF负载量为1％(质量分数)和KF/Y的焙烧温度为700 ℃时,吡啶和3-甲基吡啶总收率达到最大值.%The synthesis of pyridine and 3-picoline from the reaction of acrolein diethyl acetal,water and ammonia was conducted in a fixed-bed reactor.The catalytic activities of La-and KF-modified Y zeolites were compared.Various influencing parameters,including the loadings and modified ways of La species,the loadings of KF and the calcination temperature of KF/Y,were systematically investigated.Compared to pure Y zeolite,La-and KF-modifications can enhance the catalytic activities.The catalytic activity of La-modified Y through ion exchange is better than that of the sample through wet impregnation.The total yield of pyridine and 3-picoline reaches the maximum while the loading of La via the wet-impregnation method is 1％mass fraction and the calcination temperature of KF/Y is 700 ℃.