Cobalt Phosphate Based Zeolite Structures with the Edingtonite Framework Topology

Abstract

Hydrothermal syntheses and crystal structures of five zeolite edingtonite analogues are presented. For the first time, the edingtonite framework topology is assembled using an amine-assisted synthesis approach with either 1,2-diaminopropane or 1,2-diamino-2-methylpropane. These materials are created in the cobalt phosphate system with a small concentration of trivalent cations (Al3+ and Ga3+) incorporated into the framework for the host−guest charge matching. ACP-EDI1 and GCP-EDI1 are monoclinic, whereas ACP-EDI2, ACP-EDI3, and GCP-EDI2 are tetragonal (ACP = aluminum cobalt phosphate; GCP = gallium cobalt phosphate). The difference in lattice symmetries between ACP-EDI1 and ACP-EDI2 (or GCP-EDI1 and GCP-EDI2) is related to the synthesis conditions. All five structures have three-dimensional 8-ring channels along the crystallographic [001], [110], and [110] directions, regardless of the difference in symmetry. Amine molecules are more ordered in the monoclinic phases than in the tetragonal phases, and the...