School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P.R. China.
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, P.R. China.
Chemistry. 2018 Dec 20;24(72):19300-19308. doi: 10.1002/chem.201804193. Epub 2018 Nov 21.
Single-crystalline sponge-like MFI mesoporous zeolites (SSMZs) have been synthesized by using bolaform surfactants with an axial chiral binaphthyl core in the hydrophobic tail and triquaternary ammonium head groups, as bifunctional organic structure-directing agents (OSDAs). By changing the length of alkyl chain between a triquaternary ammonium head group and a binaphthyl group from 4 to 10 carbons, SSMZs with high specific surface area (382-434 m g ), abundant micropore-mesopore connectivity, and uniform mesopore diameter (4-10 nm) were obtained. OSDAs with an alkyl chain length of 11 and 12 carbons led to the formation of nanorod-constructed mesoporous MFI zeolites. A geometrical matching between the cylindrical arrangement of the binaphthyl groups and the zeolitic framework is speculated to be the key factor for the formation of mesoporous zeolites. The SSMZ zeolites, with abundant mesopores beneficial for the diffusion of reactants, exhibited significantly higher catalytic efficiencies than those of the conventional ZSM-5 with a microcrystal morphology (≈1.5 μm).
采用具有轴向手性联萘基核的棒状表面活性剂作为双功能有机结构导向剂（OSDA），合成了单晶海绵状 MFI 介孔沸石（SSMZ）。通过改变季铵头基团和联萘基之间的烷基链长度从 4 个碳到 10 个碳，得到了具有高比表面积（382-434 m2/g）、丰富的微孔-介孔连通性和均匀介孔直径（4-10nm）的 SSMZ。烷基链长为 11 和 12 个碳的 OSDA 导致形成纳米棒构建的介孔 MFI 沸石。联萘基的圆柱排列与沸石骨架之间的几何匹配被推测是形成介孔沸石的关键因素。具有丰富介孔的 SSMZ 沸石有利于反应物的扩散，表现出比具有微晶体形态（≈1.5μm）的常规 ZSM-5 更高的催化效率。
