摘要
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
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
1997年第6期514-518,共5页
Journal of Fuel Chemistry and Technology
关键词
SAPO-11
分子筛
线性丁烯
骨架异构
催化剂
SAPO11 molecular sieve, synthesis with iPr 2NH, skeletal isomerization of linear butylenes, IR, NH 3TPD