AlPO-91: A 16-Layer ABC‑6 Aluminophosphate with Five Distinct Cage Types

The properties and pore structure of microporous materials are dictated by the composite building units that link together to form the crystal structure. Cage-based building units predominate in the ABC-6 family of molecular sieves, and of all the known ABC-6 materials, none are observed to have more than four different cage types in their framework structure. We present here a new aluminophosphate material, AlPO-91, which has five distinct cage types present in its framework. AlPO-91 was discovered through modifications to the synthesis of a related and previously reported material, AlPO-78. AlPO-91 and AlPO-78 represent an interesting subclass of ABC-6 materials in which a number of d6r and s6r subunits are equal. This property has important implications for the porosity and potential applications of AlPO-91 and related materials.