西班牙马德里材料科学研究所Miguel A. Camblor等组成的国际研究团队开发出了链间膨胀的特大孔沸石。相关论文于2024年3月27日发表在《自然》杂志上。

在该研究中，小组通过分离和连接链间的嵌入式硅化剂来膨胀一维硅酸盐链，从而产生热稳定和水热稳定硅酸盐，这种策略与层状沸石前驱体的层间膨胀类似。结果表明，他们得到了沿3个晶体学方向分别有20、16和16个硅四面体孔径的超大孔隙的沸石。所制备的链间扩展沸石含有悬垂的Si-CH3基团，通过煅烧，它们相互连接，形成一个真正的、完全连接的(除了可能存在的缺陷)三维沸石框架，密度非常低。此外，它还独具在任何类型的沸石中都没有见过的三重四环单元。

研究人员表示，这里报道的硅酸盐膨胀-冷凝方法可能适用于进一步的超大孔沸石形成。钛可以被引入这种沸石中，从而形成一种催化剂，在涉及较大尺寸分子的液相烯烃氧化中具有活性，这在以过氧化氢异丙苯为氧化剂的环氧丙烷的工业化清洁生产中显示出前景。

据了解，具有超大孔径的、开口环超过12个四面体的稳定的铝硅酸盐沸石，可以处理比目前沸石材料能处理的更大的分子。然而，直到最近它们仍然难以合成。

附：英文原文

Title: Interchain-expanded extra-large-pore zeolites

Author: Gao, Zihao Rei, Yu, Huajian, Chen, Fei-Jian, Mayoral, Alvaro, Niu, Zijian, Niu, Ziwen, Li, Xintong, Deng, Hua, Mrquez-lvarez, Carlos, He, Hong, Xu, Shutao, Zhou, Yida, Xu, Jun, Xu, Hao, Fan, Wei, Balestra, Salvador R. G., Ma, Chao, Hao, Jiazheng, Li, Jian, Wu, Peng, Yu, Jihong, Camblor, Miguel A.

Issue&Volume: 2024-03-27

Abstract: Stable aluminosilicate zeolites with extra-large pores that are open through rings of more than 12 tetrahedra could be used to process molecules larger than those currently manageable in zeolite materials. However, until very recently1,2,3, they proved elusive. In analogy to the interlayer expansion of layered zeolite precursors4,5, we report a strategy that yields thermally and hydrothermally stable silicates by expansion of a one-dimensional silicate chain with an intercalated silylating agent that separates and connects the chains. As a result, zeolites with extra-large pores delimited by 20, 16 and 16 Si tetrahedra along the three crystallographic directions are obtained. The as-made interchain-expanded zeolite contains dangling Si–CH3 groups that, by calcination, connect to each other, resulting in a true, fully connected (except possible defects) three-dimensional zeolite framework with a very low density. Additionally, it features triple four-ring units not seen before in any type of zeolite. The silicate expansion–condensation approach we report may be amenable to further extra-large-pore zeolite formation. Ti can be introduced in this zeolite, leading to a catalyst that is active in liquid-phase alkene oxidations involving bulky molecules, which shows promise in the industrially relevant clean production of propylene oxide using cumene hydroperoxide as an oxidant.

DOI: 10.1038/s41586-024-07194-6

Source: https://www.nature.com/articles/s41586-024-07194-6