【摘要】 以工业柱层硅胶为硅源,考察了静态条件下多种因素对高硅MCM-22分子筛合成的影响.结果表明,影响高硅MCM-22分子筛合成的最主要因素是碱度、温度和模板剂浓度的不均匀性.提高成核速率同时降低晶化速率有利于纯的高硅MCM-22分子筛合成.实验发现,晶种的结构和溶解性能对晶化速率及结晶度有影响,几种晶种的效果为:合成母液>ITQ-2（P）>MCM-22（P）>MCM-22.在静态条件下模板剂形成的浓度梯度是合成时易形成杂晶的重要原因之一.静态条件下遵循"快速成核慢速生长"同时晶化期间倒置反应釜减小因模板剂浓度梯度造成影响的合成策略在凝胶组成SiO₂/Al₂O₃=100的体系中成功地合成出了纯的高硅MCM-22分子筛.更多还原

【Abstract】 Using silica gel for column chromatography as silica source,the influences of various factors on the synthesis of high-silica MCM-22 are investigated under static hydrothermal crystallization condition. The results show that the crystallization temperature,alkalinity and nonuniformiry of the concentration of template are the three most important factors to the synthesis of high-silica MCM-22. Improving rate of nucleation and reducing rate of crystallization are beneficial to the synthesis of high-silicon MCM-22. Experiments have found that the structure and dissolution properties of seed crystals have an influence on the crystallization rate and crystallinity. The active order of the several seeds is the synthesis mother liquor≈ITQ-2( P) > MCM-22( P) > MCM-22. The nonuniformiry of the concentration of template owing to concentration gradient formed under static condition is one of the important reasons to affect the synthesis of pure high-silica MCM-22. Pure high-silica MCM-22 zeolite is synthesized successfully under static condition in the synthetic system of Si O2/Al2 O3 gel= 100 by the following synthetic principle : fast nucleation,slow growth and reversing the autoclave during crystallization process for reducing the influence of concentration gradient of template on synthesis.更多还原