CTAB modification of MCM-49 zeolite containing HMI and its acylation of anisole

详细信息    查看全文

• 作者：Huijuan Wei^a ; ^b ; Sujuan Xie^a ; Kefeng Liu^a ; ^c ; Wenjie Xin^a ; Xiujie Li^a ; Shanhe Liu^d ; Shunming Gu^d ; Shenglin Liu^a ; Longya Xu^a ; ^{lyxu@dicp.ac.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：MCM-49 zeolite ; Template ; Post-treatment ; CTAB ; Acylation
• 刊名：Chinese Journal of Catalysis
• 出版年：2015
• 出版时间：October 2015
• 年：2015
• 卷：36
• 期：10
• 页码：1766-1776
• 全文大小：768 K

文摘

A series of MCM-49 zeolite catalysts containing different amounts of the hexamethyleneimine (HMI) template were calcined at different temperatures, and then modified with cetyltrimethylammonium bromide (CTAB). Changes in structural and acidic properties were investigated by XRD, N₂ adsorption, NH₃-TPD, adsorbed pyridine infrared and DRIFTS measurements, and ²⁹Si and ²⁷Al MAS NMR. There were cleaning off of amorphous particles and extraframework Al atoms inserted into the framework of the zeolite due to the CTAB modification. These two effects resulted in more framework Al in the CTAB modified samples than the untreated samples, and a higher Brönsted acid concentration, which was confirmed by the acylation of anisole with acetic anhydride. The catalytic roles of the acid sites located in the different pore systems in the zeolite were investigated. It was verified that the active sites after CTAB modification were mainly in the HMI-free regions.