A Stable Mesoporous Zeolite with Unprecedented 36-Ring Channels

Expanding the pore size of zeolites beyond the microporous regime has long been constrained by conventional organic structure-directing agents (OSDAs). Here we report JU-69, a mesoporous pure-silica zeolite featuring one-dimensional 36-ring channels, which represent the largest apertures observed in any tetrahedral framework, and an ultralow framework density (9.53 T/1000 Å3). A surfactant-like phosphonium OSDA, combining bulky head groups with a long alkyl chain, directs the formation of columnar assemblies that template long-range-ordered mesoporous walls. Three-dimensional electron diffraction reveals a trigonal framework constructed from three composite building units (CBUs), including two previously unknown CBUs that generate chiral clover motifs and circular 36-ring pores. JU-69 shows outstanding stability up to 900 ℃ and hosts periodically arranged silanol groups ideal for metal anchoring, exemplified by active Pd/JU-69 hydrogenation catalysts. This work establishes a new pathway for designing crystalline mesoporous zeolites with unprecedented structural openness.