The crystal structure of zeolite Linde Q: A proposal based on powder X-ray diffraction and 27Al and 29Si MAS n.m.r. spectroscopy

The BPH topology is proposed for the tetrahedral framework of the synthetic zeolite Linde Q (hexagonal; a = 13.501(9) A; c = 13.403(19) A; P321; unit cell composition (104 °C); 7 K 2 O·7 Al 2 O 3 ·14 SiO 2 ·21.7 H 2 O). The one-dimensional 12-ring channel along [001] intersects with a two- dimensional intersecting channel system parallel to (001) with eight-ring apertures. The “sheetlike” structure accounts for the low framework density and the low thermal stability. The positions of four extraframework cation sites and four water molecules is also proposed. This structure type with completely ordered Si, Al distribution is consistent with 29 Si MAS n.m.r. spectroscopy and with its chemical and physical properties.