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

Synthesis of Pyridine and 3-Picoline from Acrolein Diethyl Acetal and Ammonia over La-and KF-modified Y Type Zeolite Catalysts

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 ℃.