Design and Synthesis of a Medium‐Pore Aluminosilicate Zeolite SCM‐53

Designing and synthesizing condensed, thermally stable zeolites by inverse sigma expansion of open‐framework zeolites has been well achieved. However, creating thermally stable open‐framework zeolites through sigma expansion of condensed‐frameworks remains rare. Herein, we present the rational design and synthesis of a thermally stable medium‐pore aluminosilicate zeolite SCM‐53, which possesses a 2D 10 × 10‐ring channel system. The framework of SCM‐53 was theoretically predicted by sigma expansion of the framework of SCM‐51, a small‐pore aluminosilicate zeolite featuring a 2D 8 × 8‐ring channel system prepared by calcination of the layered precursor SCM‐50. SCM‐53 was rationally synthesized by successive interlayer silylation and calcination treatments of SCM‐50. The structure of SCM‐53 was validated by powder X‐ray diffraction (PXRD), scanning transmission electron microscopy (STEM), nuclear magnetic resonance (NMR) spectroscopy, and N 2 absorption measurement. Our results demonstrate that SCM‐53 possesses accessible micropores (5.9 × 4.9 Å), an ultrathin nanosheet morphology (∼15 nm), and high thermal stability (up to 800 °C), suggesting its potential for adsorption and catalytic applications. We anticipate that sigma expansion offers a promising approach for the rational design and synthesis of targeted novel zeolite structures.