Investigation of Zr-incorporated mesoporous titania materials via nonsurfactant templated sol-gel route: Synthesis, characterization and stability

The synthesis of Zr-incorporated mesoporous titania materials was achieved by a HCl-catalyzed nonsurfactant templated sol-gel process, followed by solvent extraction to remove the urea template. The materials were characterized by FT-IR, X-ray energy dispersive spectroscopy (XEDS), nitrogen adsorption-desorption measurement (BET), powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). Zirconia has been successfully incorporated into the skeleton of titania and the observed Zr/Ti compositions are close to the designed Zr/Ti molar ratios in the feeds. The content of zirconia has significant effects on the mesoporosity and the pore parameters as well as the thermal and hydrothermal stabilities of the materials. Anatase crystal structures were formed in the materials with low Zr/Ti molar ratios. As the Zr/Ti ratio is increased, the content of anatase structures decreases and the material becomes essentially amorphous at the Zr/Ti ratio of 1/1. The materials have narrowly distributed average pore diameters in the range of 2.5-5.1 nm and disordered pore or channel structures. The incorporation of Zr increases the thermal stability but decreases the hydrothermal stability of the materials. (C) 2003 Kluwer Academic Publishers.