An "Unachievable" Molecular Sieve with Sole Six-Membered Rings

The frameworks of zeolite molecular sieves constructed from a sole type of ring, such as 6-membered rings (6MRs), are regarded as unachievable structures that would not even be found in hypothetical zeolite databases containing tens of millions of structures. Herein, we for the first time report a novel aluminophosphate ZJM-11 molecular sieve, with a fully 6-membered ring (6MR) framework, which was successfully obtained from topotactic transformation. The obtained structure, which possesses fully opened micropores, represents a rare case of a single-ring zeolite topology with an ultrahigh framework density, viewed from the perspective of conventional wisdom as an "unachievable" molecular sieve. Advanced characterizations unveil the dynamic framework reconstruction mediated by ZJM-9 and/or ZJM-10 intermediates, pinpointing this structural evolution as the essential step toward ZJM-11 formation. This work therefore delivers critical knowledge for the rational design of unconventional zeolite molecular sieves.