催化学报

催化学报 ›› 2009, Vol. 30 ›› Issue (1): 60-64.

• 研究论文 • 上一篇    下一篇

膨胀剂用量、合成体系pH值和MCM-22(P)的硅/铝比对ITQ-2分子筛合成的影响

王保玉1,吴建梅2,袁忠勇3,项寿鹤3   

  1. 1 洛阳师范学院化学化工学院, 河南洛阳 471022; 2 国家海洋局天津海水淡化与综合利用研究所, 天津 300192; 3 南开大学化学学院新催化材料科学研究所, 天津 300071
  • 收稿日期:2009-01-25 出版日期:2009-01-25 发布日期:2012-10-17

Effects of Swelling Agents Amount, pH Value of the System, and the SiO2/Al2O3 Ratio of MCM-22(P) on the Synthesis of ITQ-2 Zeolite

WANG Baoyu1*, WU Jianmei2, YUAN Zhongyong3, Xiang Shouhe3   

  1. 1 College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022, Henan, China; 2 The Institute of Seawater Desalination and Multipurpose Utilization, SOA, Tianjin 300192, China; 3 Institute of New Catalytic Materials Science, College of Chemistry, Nankai University, Tianjin 300071, China
  • Received:2009-01-25 Online:2009-01-25 Published:2012-10-17

PDF

879

被引次数

5

摘要： 考察了膨胀剂的用量、合成体系的pH值和MCM-22(P)的硅/铝比对合成ITQ-2分子筛的影响. 结果表明,同时降低膨胀剂十六烷基三甲基溴化铵和四丙基氢氧化铵的用量,在pH=11.5时4 h即可完成对MCM-22(P)的插层膨胀; pH值降低时,可减小由于脱硅对ITQ-2分子筛硅/铝比下降的影响,并且使产物收率大幅度提高. 同时, pH值降低使后续的超声剥离更加容易,且可避免生成MCM-41介孔分子筛杂相. MCM-22(P)的硅/铝比越大,层表面的电荷密度越低,带负电荷的层板和阳离子插层剂之间的静电引力和分子间作用力也就越小,致使插层膨胀和随后的超声剥离越容易.

关键词: MCM-22分子筛, 十六烷基三甲基溴化铵, 四丙基氢氧化铵, 插层膨胀, 超声剥离, ITQ-2分子筛

Abstract: The amount of swelling agents (CTMABr, TPAOH) and the pH value of the synthesis system were the most important factors for the intercalation swelling of CTMA+ into the sheets of MCM-22(P). The well-swollen MCM-22(P) could be o btained when MCM-22(P)∶CTMABr∶40%TPAOH∶H2O mass ratio was 1∶1∶1.1∶16. With the pH value decreasing, the desiliconization of MCM-22(P), which resulted in a decre a se of the SiO2/Al2O3 ratios of ITQ-2, greatly decreased, the yield of ITQ - 2 zeolite significantly increased, and the ultrasonic exfoliation process becam e more accessible.The MCM-41 mesophase could be avoided when the exfoliat ion process was performed at lower pH value.

Key words: MCM-22 zeolite, cetyltrimethylammonium bromide (CTMABr), tetrapropylammonium hydroxide (TPAOH), intercalation swelling, ultrasonic exfoliation, ITQ-2 zeolite