SAPO-11分子筛用i-Pr_2NH导向合成及其酸性研究

STUDIES ON SYNTHESIS AND ACIDITY OF A SINGLE ORGANIC COMPUND TEMPLATED SAPO11 MOLECULAR SIEVE

以ＡｌＰＯ４、Ｈ３ＰＯ４、ＳｉＯ２等为原料采用单一模板剂ｉＰｒ２ＮＨ合成了ＳＡＰＯ１１分子筛，利用Ａｖｒａｍｉ方程等对合成过程进行了定量描述。还利用红外（ＩＲ）、程序升温脱附（ＴＰＤ）、线性丁烯骨架异构反应催化活性测试等手段表征了ＳＡＰＯ１１的酸性。结果表明，合成过程随温度有明显变化，晶化阶段的活化能远高于核化阶段的值。可用Ａｖｒａｍｉ方程的参数来表征合成过程的难易程度。分子筛中存在Ｂ酸和Ｌ酸位，主要在中等强度范围，从而对线性丁烯骨架异构反应有较好的催化活性。提高分子筛中硅含量可明显增大酸位浓度，酸强度也有轻度增强。

SAPO11 molecular sieve was synthesised from mixtures of AlPO 4 and SiO 2 sol using iPr 2NH as a novel template The processes were quantified by Avrami equation IR, TPD and catalytic skeletel isomerization of linear butylenes were used to characterize the acidity of the SAPO11 samples It was found that the crystallization energy was evidently higher than the nucleation energy Parameters in Avrami equation were discussed to elucidate the easeness of the synthesis processes Both Bronsted and Lewis acidic sites were measured and were in medium strength range A sample with a framework composition of (Al 0.50 P 0.45 Si 0.05 )O 2 showed better activity than the other samples for the skeletal isomerization of linear butylenes