aluminogermanosilicate zeolite,SCM-25,synthesis of zeolite,physicochemical properties,Baeyer-Villiger oxidation,"/>
Al-SCM-25分子筛的合成及其催化性能研究
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Synthesis and Catalytic Performance of Al-SCM-25 Zeolite
FU Wenhua, LI Xiangcheng, TAO Weichuan
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, SINOPEC Shanghai Research Institute of Petrochemical Technology Company Limited, Shanghai 201208, China
摘要 将Al引入硅锗分子筛骨架是提升其骨架稳定性、增强酸性的有效手段。本工作首次采用直接合成法将Al引入SCM-25分子筛骨架，制备了不同铝含量的Al-SCM-25分子筛。考察了水量、铝含量、晶种添加对合成的影响，发现与SCM-25分子筛的合成相比，Al-SCM-25分子筛需要在更高的水量和晶种存在的条件下才可以完全结晶。采用N2物理吸附、27Al魔角旋转固体核磁（27Al MAS NMR）、氨气程序升温脱附（NH3-TPD）等手段表征了Al-SCM-25分子筛的孔结构性质、铝配位状态及酸性。结果表明，Al-SCM-25具有与SCM-25相近的比表面积和微孔体积；大部分铝以四配位形式进入骨架中，从而产生了比SCM-25分子筛数量更多、强度更高的酸性位。在环己酮Baeyer-Villiger氧化制备ε-己内酯反应中，Al-SCM-25分子筛相较SCM-25分子筛表现出更高的环己酮转化率和目标产物的收率，并且具有较好的循环稳定性。
Abstract：Introduction of Al element into framework has been proven to stabilize the framework and enhance the acidity of germanosilicate zeolite. In this contribution, the introduction of Al elements into the framework of SCM-25 zeolite was reported for the first time. Consequently, Al-SCM-25 zeolites with various aluminum content were prepared. The effects of water content, aluminum content, and the addition of seeds were investigated. It turned out that compared to the synthesis of Al-free SCM-25 zeolite, Al-SCM-25 zeolites could only completely crystallize at higher water content and the presence of seeds. The physicochemical properties of Al-SCM-25 zeolites, including textural properties, the coordination state of Al atoms, and the acidity were characterized by the combination of N2 physisorption, 27Al solid-state magic angle spinning solid nuclear resonance (MAS NMR) spectra and temperature-programmed desorption of NH3 (NH3-TPD) techniques. The Al-SCM-25 zeolites were of comparable specific surface area and micropore volume to SCM-25 zeolite. Major Al atoms were incorporated into the framework in tetrahedrally cooperated state, thus generating more substantial and stronger acid sites than SCM-25 zeolite. Moreover, Al-SCM-25 zeolites demonstrated higher cyclohexanone conversion and ε-caprolactone yield than Al-free counterpart in the Baeyer-Villiger oxidation of cyclohexanone, and recycle stability.
FU Wenhua,LI Xiangcheng,TAO Weichuan. Synthesis and Catalytic Performance of Al-SCM-25 Zeolite[J]. Chemical Reaction Engineering and Technology, 2024, 40(2): 142-149.
