Preparation and Characterization of Pillared Zirconium Phosphite-Diphosphonates with Tuneable Inter-Crystal Mesoporosity

A series of -pillared zirconium phosphite-diphosphonates of general formula Zr(O₃PH)_x(O₃P-C₆ H₄-PO₃)_y was prepared in water, dimethylsulfoxide-water andn -propanol-water, by changing the ratios and the concentrations of the reagents. Pure mesoporous solids with a large surface area (230 to 400 m² g^-2) and a great pore volume (0.3 to 0.7 cm³ g^-2) were obtained. These materials showed a narrow distribution of pores that was tuneable over the range 4–14 nm diameter by simply varying the conditions of preparation, especially the concentration of the reagents. The formation of interparticle mesoporosity has been attributed to edge-edge interactions between rigid packets of a few pillared -layers giving rise to stable aggregates with a house of cards structure.