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 dodecylphosphate surfactants was found to produce a mesostructure similar to MCM-4I. Surfactant removal without concomitant pore collapse can be accomplished, yielding mesoporous materials with specific surface areas as high as 560 m²/g. Zr-TMS1 has been found stable to at least 800 °C, retaining surface areas greater than 200 m²/g. Longer-chained alkylphosphates led to larger pore diameters and surface areas. Lewis and Brønsted 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 acid catalyst and catalyst support material.