复旦大学孙正宗团队报道了二维MWW沸石的外延生长。相关研究成果于2024年3月16日发表于国际顶尖学术期刊《美国化学会杂志》。

具有高纵横比的二维（2D）沸石比其三维（3D）沸石具有更多的开放骨架和可接近的活性位点。然而，获得2D沸石的传统方法往往会导致结构损伤和广泛的骨架缺陷，阻碍分子分离中的有效选择性。

该项研究中，研究人员首次提出了由六方氮化硼（h-BN）引导的2D沸石（Epi-MWW）的直接外延合成，其具有与MWW沸石的位置晶格的重合匹配。生长的Epi-MWW沸石具有高结晶度和完整的六边形2D形态，平均厚度为10nm，纵横比超过50。由于其优异的分子可及性，邻二甲苯（OX）和对二甲苯（PX）的扩散时间常数分别是传统MCM-22的12倍和133倍。根据理想吸附溶液理论计算，Epi-MWW的PX/OX选择性是MCM-22的7.4倍。

附：英文原文

Title: Epitaxial Growth of Two-Dimensional MWW Zeolite

Author: Hongbin Li, Chunna Zhang, Qiang Lin, Feng Lin, Taishi Xiao, Kexin Yan, Bin Shen, Hongbin Zhang, Yi Tang, Zhengzong Sun

Issue&Volume: March 16, 2024

Abstract: Two-dimensional (2D) zeolite, with a high aspect ratio, has more open skeletons and accessible active sites than its three-dimensional (3D) counterpart. However, traditional methods of obtaining 2D zeolites often cause structural damage and widespread skeleton defects, hindering  efficient selectivity in molecular separation. In this study, we present, for the first time, a direct epitaxial synthesis of 2D zeolite (Epi-MWW) guided by hexagonal boron nitride (h-BN) with a coincidence matching of site lattices to MWW zeolite. The as-grown Epi-MWW zeolite possesses a high crystallinity and intact hexagonal 2D morphology, with an average thickness of 10 nm and an aspect ratio of over 50. Thanks to its excellent molecular accessibility, the diffusion time constants of o-xylene (OX) and p-xylene (PX) are as 12 and 133 times higher than those of conventional MCM-22, respectively; the PX/OX selectivity of Epi-MWW is 7.4 times better than MCM-22 as calculated by the ideal adsorbed solution theory.

DOI: 10.1021/jacs.4c00162

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c00162