Extra-large and intersecting pores: Thermally stable zeolites with large pores, such as zeolite Y with 12-membered rings, are used for converting large molecules from petroleum into smaller, more useful hydrocarbons. Lin et al . report the synthesis of ZEO-1, a thermally stable zeolite with extra-large, 16-membered rings. The use of tricyclohexylmethylphosphonium as an organic structure–directing agent created a zeolite with a fully interconnected multidimensional framework and a very high specific surface area. —PDS
Zeolites are microporous silicates with a large variety of applications as catalysts, adsorbents, and cation exchangers. Stable silica-based zeolites with increased porosity are in demand to allow adsorption and processing of large molecules but challenge our synthetic ability. We report a new, highly stable pure silica zeolite called ZEO-3, which has a multidimensional, interconnected system of extra-large pores open through windows made by 16 and 14 silicate tetrahedra, the least dense polymorph of silica known so far. This zeolite was formed by an unprecedented one-dimensional to three-dimensional (1D-to-3D) topotactic condensation of a chain silicate. With a specific surface area of more than 1000 square meters per gram, ZEO-3 showed a high performance for volatile organic compound abatement and recovery compared with other zeolites and metal-organic frameworks.
IDM‐1 is a new silica zeolite with an ordered and well‐defined framework constructed by alternating pentasil layers and interrupted layers, giving rise to an intersecting system of straight medium pores and undulating extra‐large lobed pores. This unique structure was solved by rotation electron diffraction and refined against synchrotron powder X‐ray diffraction data. Despite the presence of both Si(OSi)3(OH) and Si(OSi)2(OH)2 sites, this new zeolite presents high thermal stability, withstanding calcination even to 1000 °C. The location of defects at specific sites of the structure results in alternating hydrophobic SiO2 and hydrophilic SiO(2−x)(OH)2x intracrystalline regions. This peculiar combination of intersecting medium and extra‐large pores and alternating regions of different chemical character may provide this zeolite with unique catalytic properties.