Control of the textural properties of zirconium oxide

Several methods of preparation of pure and doped zirconia are compared, including aqueous precipitations, surfactant-aided syntheses, decomposition of salts, molten salt technique and kneading of wet hydrous zirconia with transition metal salts. The influence of the different preparation parameters on the textural properties of the solids is analysed, in order to design the optimal preparation technique leading to zirconia samples combining high surface areas and large pores required for use in catalytic processes. The best results have been obtained from the ageing of aqueous precipitates (surface area 267 m(2)/g, mean pore size 6 nm), from reactions in molten nitrate-carbonate mixtures (140 m(2)/g, 9 nm) and (Ni)Mo-doped molten salt preparations of ZrO2 (270 m(2)/g, 3.5 nm). This opens a wide field of possible applications for Zr-based catalysts.