预积炭对FER分子筛催化正丁烯骨架异构反应性能的影响

摘要

A series of FER zeolites with different amount of pre-deposited carbon were prepared by pretreatment at high temperature using mixture of 1-butene and N2. The effect of pre-coking on the catalytic performances of FER zeolite in the skeletal isomerization ofn-butenes into isobutene were studied. TG-DTA results indicated that there were two kinds of carbon deposits,i.e. CarbonLT (mass loss at low temperature) and CarbonHT (mass loss at high temperature). The amount of CarbonLT increased linearly with the extension of pre-coking time,while the amount of CarbonHTremained constant after being treated for one hour. The amount of CarbonLT had closely related to the initial isobutene selectivity and the CarbonLT might deposit on the active sites where propylene and ethylene were produced.%采用1-丁烯和N2混合气对FER分子筛进行高温预积炭处理，得到一系列具有不同预积炭量的FER分子筛。对预积炭的FER分子筛进行表征，研究预积炭行为对其催化正丁烯骨架异构制异丁烯反应性能的影响。热重表征结果表明，预沉积在FER分子筛上的积炭有两种，即CarbonLT（低温失重峰）和CarbonHT（高温失重峰）。CarbonLT含量随预积炭处理时间增加而呈线性增加的趋势，而CarbonHT含量在预积炭处理1h后就基本保持不变。CarbonLT 量与初始异丁烯选择性具有较好的相关性，CarbonLT 可能沉积在诱发生成丙烯和乙烯的副反应活性中心上。