高低温磷改性β分子筛制备及其烷基化反应性能研究

对常温和高温条件下的磷改性β分子筛进行热重、核磁共振和酸性分析，并考察其在苯与乙烯烷基化反应中的反应性能。结果表明：β分子筛高温条件下引入铵根离子后，其DTG曲线在220～230 ℃之间有一明显的失重峰出现，即铵根离子进入分子筛内部；其 31P MAS NMR和27Al MAS NMR表征中在化学位移为-30.908和41.392处均有一强吸收峰，即β分子筛的骨架结构中有P（4Al）和Al（4P）四配位结构出现；其NH3-TPD酸性增强，酸量增加。评价结果表明β分子筛高温条件下引入铵根离子后，其烷基化反应性能明显提高。

STUDY ON ALKYLATION PROPERTIES OF ZEOLITE BETA MODIFIED BY PHOSPHORUS AT NORMAL AND HIGH TEMPERATURE

The zeolite beta modified by phosphorus at normal and high temperature was characterized by thermogravimetric, NMR and acid analysis, and their alkylation performance for benzene with propylene was investigated. The analysis shows that after introduction of ammonium ion into zeolite beta at high temperature, an obvious peak appears at 220-230 ℃ in DTG curve, indicating the ammonium ions coming into the zeolite; and 31P MAS NMR and 27Al MAS NMR of zeolite shows two strong peaks at chemical shift -30.908 and 41.392, demonstrating the formation of tetracoordinated structure of P (4Al) and Al (4P); The modification leads more acid sites and stranger acid, proved by NH3-TPD analysis. The alkylation performance is improved significantly after modification of the zeolite at high temperature.