Two Coexisting Forms of Simple Molecules for Directing Sesqui-Unit-Cell Zeolite Nanosheets
Mingming Peng, Zhiqiang Wang, Ju Huang, Ming Shen, Jingang Jiang, Hao Xu, Yanhang Ma, Bingwen Hu, Xue‐Qing Gong, Haihong Wu, Peng Wu
Abstract
Feasible strategies are desirable for preparing zeolitic nanosheets with opener porosities and more accessible active sites. Highly delaminated FER nanosheets (ECNU-17) with unit-cell scale thickness were hydrothermally synthesized using a simple, small, and low-cost imidazole molecule as the sole organic structure-directing agent (OSDA). The single OSDA directed the formation of the FER framework, while the π–π stacked OSDAs terminated the growth perpendicular to the zeolite sheets. The ECNU-17 nanosheet is only 2.9 nm in thickness, corresponding to one and a half FER unit cells along a-axis. With open hierarchical porosity and an enhanced external surface area of 253 m2 g–1, ECNU-17 is endowed with improved mass transport and a significantly increased number of active acid sites accessible to bulky organic molecules. The ultrathin sheets of ECNU-17 aluminosilicate display excellent activity and selectivity for the protection reaction of benzaldehyde with pentaerythritol as well as the cracking of 1,3,5-triisopropylbenzene.