A HIGH-SILICA ZEOLITE WITH A 14-TETRAHEDRAL-ATOM PORE OPENING

ZEOLITES (microporous aluminosilicates) and related molecular sieves h ave found wide application as catalysts, sorbents and ionexchange mate rials. New zeolites with large pores are much in demand(1-4), and have been sought for several decades(4-7). All known zeolites, both natura l and synthetic, contain pores comprised of 12 or fewer tetrahedrally coordinated silicon or aluminium atoms (T-atoms), but several micropor ous aluminophosphates with wider pores are now known(2,8-12). The prac tical value of these large-pore phosphate-based materials is limited, however, by their poor thermal and hydrothermal stability. Here we rep ort the synthesis of a high-silica zeolite with pores comprised of 14 T-atoms. Preliminary data indicate that this thermally stable large-po re material exhibits the kind of strong acidity that makes other zeoli tes useful catalysts.