ERS-18: A new member of the NON–EUO–NES zeolite family

ERS-18, a new small pore high silica zeolite, was synthesized using 6-azonia-spiro-[5,5]-undecane hydroxide as structure directing agent. Its crystal structure was determined ab initio by using high-resolution synchrotron X-ray powder diffraction data and the zeolite-dedicated software FOCUS. ERS-18 shows orthorhombic symmetry (s.g. Fmmm) setting with unit cell parameters: a = 34.989, b = 13.667 and c = 22.559 Å. The values of b and c parameters are in common with zeolites of the NON–EUO–NES family (IZA codes for nonasil, EU-1, and NU-87, respectively); within this group the a parameter, corresponding to the layer stacking direction, varies from ∼15.0 (NON) to ∼20.0 (EUO), to ∼25.0 Å (NES). Therefore, ERS-18 can be regarded as a new member of this family having the longest stacking parameter (i.e. ∼35.0 Å) reported so far. The ERS-18 framework is characterized by the presence of 8-ring channels (crystallographic free dimensions: 3.1 × 2.5 Å) running along the [0 1 0] direction and supercages delimited by 12-rings (crystallographic free dimensions: 6.1 × 5.2 Å, cross section; 18.4 Å, depth) aligned along [1 0 0] and off the 8-ring channels.

ERS-18 is a new small pore high silica zeolite synthesized using 6-azonia-spiro-[5,5]-undecane hydroxide as SDA. ERS-18 unprecedentedly reported framework topology is characterized by large [51262082] supercage.Figure optionsDownload as PowerPoint slideResearch Highlights
► Synthesis of a new zeolite by using azonia-spiro compounds as organic additive.
► Crystal structure solution by using high resolution X-ray powder diffraction data.
► Proof of a new framework topology expanding the NON–EUO–NES zeolite family.