【作者】 田亚杰； 刁振恒； 宫思远； 王莅； 刘国柱；

【Author】 Yajie Tian;Zhenheng Diao;Siyuan Gong;Li Wang;Guozhu Liu;School of Chemical Engineering and Technology,Tianjin University;Collaborative Innovation Center of Chemical Science and Engineering(Tianjin),Tianjin University;

【机构】 天津大学化工学院； 天津化学化工协同创新中心；

【摘要】 碳氢燃料的超临界催化裂解由于烃分子在分子筛微孔内的扩散速率大幅下降,影响了分子筛的催化性能~~[1],向微孔分子筛中引入介孔成为解决扩散限制问题的有效途径之一~[2]。本文采用两亲性硅烷(TPOAC)合成了多级孔HZSM-5分子筛~~[3],发现TPOAC可诱导形成孔径为3-5 nm的长程有序晶内介孔,具有适中的有序介孔量及酸量的多级孔HZSM-5呈现最佳的催化裂解性能。采用包埋法合成了多级孔HZSM-5分子筛,发现通过MCM-41相在介孔有序的meso-HZSM-5晶面自组装,可获得核内、壳内均介孔有序的核-壳型多级孔分子筛,其壳层厚度随合成液/meso-HZSM-5质量比而变(33-87 nm)、壳层孔径随表面活性剂链长和扩孔剂三甲苯用量而变(2.5-10 nm)。随壳层孔径增大,分子筛催化裂解性能进一步提高~~[4]。更多还原

【Abstract】 Ordered meso-HZSM-5@A1-MCM-41 zeolites were prepared by surfacant-directed encapsulating process.It was found that ordered meso-HZSM-5 which was used as core could be synthesized using a designed amphiphilic organosilane(TPOAC) as surfactant and that the mesopore size of MCM-41 shell can be adjusted by changing the chain length of surfactant(alkyltrimethylammonium bromide,CnTAB,n = 10 and 16) and the TMB amount.Catalytic cracking of supercritical n-dodecane(500 ℃,4 MPa) over the prepared samples shows that ordered meso-HZSM-5@A1-MCM-41 with the mesopored shell of 4.5-10 nm exhibits a high catalytic activity up to 28%improvement but a low deactivation rate of only one fourth compared with the meso-HZSM-5 zeolite.更多还原