SYNTHESIS AND CHARACTERIZATION OF PHOSPHATED MESOPOROUS ZIRCONIUM-OXIDE

The synthesis of zirconium oxide mesoporous molecular sieves (Zr-TMS1) comprising of hexagonally-packed cylindrical pores was investigated. Sol-gel processing of zirconium n-propoxide ligated with dodecylphosph ate surfactants was found to produce a mesostructure similar to MCM-41 . Surfactant removal without concomitant pore collapse can be accompli shed, yielding mesoporous materials with specific surface areas as hig h as 560 m(2)/g. Zr-TMS1 has been found stable to at least 800 degrees C, retaining surface areas greater than 200 m(2)/g. Longer-chained al kylphosphates led to larger pore diameters and surface areas. Lewis an d Bronsted acidity were found in Zr-TMS1, probably associated with the presence of surface phosphate groups. The extremely high surface area , pore size control, high thermal stability, and surface acidity make this transition metal mesoporous molecular sieve an attractive solid a cid catalyst and catalyst support material. (C) 1997 Acta Metallurgica Inc.