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Synthesis of ZrO2–SiO2 mesocomposite with high ZrO2 content via a novel sol–gel method

2005; Elsevier BV; Volume: 84; Issue: 1-3 Linguagem: Inglês

10.1016/j.micromeso.2005.05.014

1873-3093

Abhijit Tarafdar, Asit Baran Panda, Panchanan Pramanik,

Polyoxometalates: Synthesis and Applications

A novel, convenient, one step sol–gel technique using sodium silicate and carbonate complex of zirconium in basic medium leads to the synthesis of mesostructured zirconia–silica composite with narrow pore size distribution having moderately high surface area (360–500 m2/g). These materials were characterized by powder low angle X-ray diffraction (XRD), N2 sorption isotherms, HRTEM, 29Si-MAS NMR, and FTIR. The surface acidity of the composites has been analyzed through FTIR spectra of pyridine-adsorbed compounds. Nitrogen adsorption data, HRTEM and XRD patterns confirmed that, the structure, high surface area, and uniform pore size distribution are maintained in the synthesized composites with Si/Zr ratio of 2 to 0.5. Further increase in silica loading showed the reduction of surface area. EDX analyses show that this novel sol–gel technique efficiently avoids the leaching of zirconium and silica from the framework of the material. The calcined ZrO2–SiO2 mesocomposite show worm-like pores in the microstructure and have both Brönsted and Lewis acid sites.