Understanding the Fundamentals of Microporosity Upgrading in Zeolites: Increasing Diffusion and Catalytic Performances

Hierarchical zeolites are regarded as promising catalysts due to their well-developed porosity, increased accessible surface area, and minimal diffusion constraints. Thus far, the focus has been on creation of mesopores in zeolites, however, little is known about a microporosity upgrading its effect catalytic performance. Here authors show that “birth” mesopore formation faujasite (FAU) type zeolite starts by removing framework T atoms from sodalite (SOD) cages followed propagation throughout crystals. This evidenced following xenon (Xe) mesoporous FAU prepared unbiased leaching with NH4F comparison pristine zeolite. A new pathway for Xe proposed. Xenon first penetrates through opened SOD then diffuses supercages Density functional theory (DFT) calculations indicate between cage supercage occurs only hierarchical structure defect-contained six-member-ring separating these two types cages. The performance further indicates upgraded facilitates intracrystalline molecular traffic increases