Yu Xue, Liu Bing, Zhang Yuewei
Jilin Institute of Chemical Technology, Jilin, 132022, PR China.
National Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012, PR China.
Heliyon. 2019 May 21;5(5):e01640. doi: 10.1016/j.heliyon.2019.e01640. eCollection 2019 May.
A series of HZSM-5 catalysts with different Si/Al ratio were prepared and characterized with various characteristic methods XRD, BET, NH-TPD, FT-IR spectra of adsorbed pyridine, etc. The effect of Si/Al ratio of HZSM-5 catalysts on the prins condensation of isobutylene and formaldehyde to isoprene was investigated in detail. It is resulted that the catalytic activities are dependent on the acid strength, decreasing with the ratio of Si/Al increases. The optimized catalyst was HZSM-5 (600) with 8.8% of isobutene conversion and 90.2% of selectivity to isoprene, indicating that the higher Si/Al ratio was termed as appropriate for prins condensation of isobutylene and formaldehyde to isoprene. On the contrary, the low Si/Al ratio may lead to the formation of by-products and coke deposits, which leads the catalysts deactivation.
制备了一系列具有不同硅铝比的HZSM-5催化剂，并用XRD、BET、NH-TPD、吸附吡啶的FT-IR光谱等各种表征方法对其进行了表征。详细研究了HZSM-5催化剂的硅铝比对异丁烯与甲醛Prins缩合生成异戊二烯的影响。结果表明，催化活性取决于酸强度，随硅铝比的增加而降低。优化后的催化剂是HZSM-5(600)，异丁烯转化率为8.8%，异戊二烯选择性为90.2%，这表明较高的硅铝比适合异丁烯与甲醛Prins缩合生成异戊二烯。相反，低硅铝比可能导致副产物的形成和焦炭沉积，从而导致催化剂失活。
