Versatile phosphorus-structure-directing agent for direct preparation of novel metallosilicate zeolites with IFW-topology

Abstract To fabricate a novel metallosilicate zeolite with tridirectional pore system of 8- and 10-ring channels, direct incorporation B, Al Ga into small medium ITQ-52 the IFW-type topology was carried out using phosphorus-containing organic structure-directing agent (P-OSDA, 1,4-butanediylbis[tris(dimethylamino)]phosphonium hydroxide). The solids were characterized by XRD, FT-IR, 11B, 27Al, 31P 71Ga MAS NMR spectroscopy before after post-synthesis treatments steaming. It found that P-species derived from OSDA decomposed heat treatments, forming extra-framework phosphates remain in cavities zeolite. presence not only stabilized or located framework positions which adopted reversible octahedral configuration but also decreased acid strength zeolites. catalytic performance Al- Ga-containing zeolites MTO reaction investigated. We have P enhanced life time, optimum content for samples Si/Al = 120 Si/Ga = 135 to be P/Al = 0.17 P/Ga = 0.14, respectively, showing propene selectivity higher than 35%.