Highly Ordered Porous Zirconias from Surfactant-Controlled Syntheses: Zirconium Oxide−Sulfate and Zirconium Oxo Phosphate

The syntheses and characterization of mesostructured hexagonally ordered surfactant composites using zirconium sulfate ions as inorganic precursor species are described. On the basis of the mesostructured zirconium sulfate surfactant composites, two porous MCM-41 analogues have been synthesized: zirconium oxide−sulfate and zirconium oxo phosphate. For the zirconium oxo phosphates, a special postsynthetic treatment has been developed. The pore arrangements and wall structures were characterized by XRD, nitrogen adsorption, EXAFS, and TEM. The porous zirconia based materials show hexagonal arrangements of uniformly sized pores and amorphous pore walls. Both zirconium oxide−sulfate and zirconium oxo phosphate show remarkable thermal stability up to 500 °C. Therefore, the surfactant has been completely removed from the structures by calcination. So far, this is the highest thermal stability compared to other porous transition metal oxides prepared via surfactant-controlled synthesis.