晶种辅助蒸气转化Al-SBA-15合成Beta纳米晶团聚体  

Synthesis of Beta Nanocrystal Aggregates from Al-SBA-15 via Seed-assisted Steaming Conversion

作　　者：孙琳 林森[1] 王润伟[2] SUN Lin;LIN Sen;WANG Runwei(College of Materials Science and Engineering,Qingdao University of Science and Technology,Qingdao 266042,China;State Key Laboratory of Inorganic Synthesis and Preparative Chemistry,College of Chemistry,Jilin University,Changchun 130012,China)

机构地区：[1]青岛科技大学材料科学与工程学院,青岛266042 [2]无机合成与制备化学国家重点实验室,吉林大学化学学院,长春130012

出　　处：《高等学校化学学报》2024年第8期35-42,共8页Chemical Journal of Chinese Universities

基　　金：山东省自然科学基金(批准号:ZR2022MB030);国家自然科学基金(批准号:21390394,21771082,21771081,21703128,51472256)资助.

摘　　要：采用晶种辅助蒸气转化(SASC)策略,将有序介孔分子筛Al-SBA-15颗粒直接转化为Beta纳米晶团聚体(BNA).除规则微孔外,BNA含有2种多级介孔结构.研究了骨架组装与多级孔结构的关系.通过调节热分解条件,将P123胶束选择性分解成碳颗粒并分散于Al-SBA-15介孔中,在颗粒内部构建了均匀的三维纳米空间网格.通过浸渍Beta晶种和四乙基铵阳离子(TEA+)强化分子筛成核,采用蒸气处理方法,将Al-SBA-15无定形孔壁在纳米空间中缓慢转化为Beta纳米晶体.通过调节合成参数,使纳米晶体沿Al-SBA-15孔壁方向规则排列,形成有序介观结构.此外,经高温焙烧去除碳颗粒后,BNA内部生成了穴状介孔.实验结果表明,低的溶剂用量可显著降低传质速度,提高骨架组装质量,从而使BNA酸性增强.优异的多级孔结构和较强的酸性使BNA在大分子反应中具有应用潜力.Beta nanocrystal aggregates(BNA)possessing two types of hierarchical mesopores have been synthesized by the one-step conversion of the ordered mesoporous material Al-SBA-15 following a seed-assisted steaming conver-sion(SASC)strategy.The relationship between the assembly of the Beta zeolite and the evolution of hierarchical mesostructure was systematically investigated.Using a controllable thermal treatment,the P123 micelle was selectively decomposed to form the carbonaceous particles that highly dispersed inside the mesopores,and then a new three-dimensional nanosized space network was constructed in the whole Al-SBA-15 bulky particles.With the help of the pre-impregnated Beta seed solution and tetraethylammonium cation(TEA+)template,the amorphous Al-SBA-15 walls were slowly converted to the Beta nanocrystals in these spaces under the low-solvent-content conditions.By adjusting the synthesis parameters,the resulting nanocrystals arranged along the Al-SBA-15 wall direction and formed a newly ordered mesostrcuture.In addition,the BNA has another kind of large cavity that connected through the mesopores after the removal of carbonaceous particles.On the other hand,the high-quality framework assembly derived from the slow mass transfer directly caused the strong acidity of the final BNA.The strong acidity combined with the excellent hierarchical textural characteristic endow BNA with great application potential in acid catalytic reactions involving large molecules.

关 键 词：多级孔Beta纳米晶 Al-SBA-15 晶种辅助蒸气转化 骨架组装 

分 类 号：O614[理学—无机化学] O643.3[理学—化学]