Preparation and characterisation of mesoporous zirconium oxide Original Research Article

Mesoporous zirconium oxides were obtained using the polymeric sol–gel procedure. The synthesis was carried out in the presence of two series of surfactants, namely, N(Cn)4Br and N(CH3)3CnBr, with n=8–18, and Cn, the linear alkyl chain. Hydrolysis of zirconium isopropoxide was carried out both under acid and base catalysis, and also using acetylacetone (acac) as a stabiliser. In order to obtain information on the sol–gel procedure in the above conditions, the composition parameters: Zr/H2O and Zr/surfactant ratios were modified in a rather wide interval. Mesoporous textures were obtained, with surface areas and pore size distributions depending on the synthesis conditions. The evolution of the sol–gel process and the resulting oxides were characterised with several tools: nitrogen adsorption–desorption isotherms, TG-DTA, XRD, SAXS, FTIR, 13C-CP/MAS NMR, and XPS measurements. The results showed that the phase structure of ZrO2 is sensitive to the composition parameters, and confirmed that in the presence of surfactants, the synthesis occurred via a scaffolding mechanism.