PHASE FORMATION IN MIXED TiO2-ZrO2 OXIDES PREPARED BY SOL-GEL METHOD
E. Kraleva1, M.L. Saladino2, R. Matassa3, E. Caponetti4, S. Enzo5, A. Spojakina1
1 Institute of Catalysis Bulgarian Academy of Sciences 2 Dipartimento di Chimica ″S. Cannizzaro″ Università di Palermo and INSTM-Udr Palermo 3 Centro Grandi Apparecchiature-UniNetLab, Università di Palermo 4 Dipartimento di Chimica ″S. Cannizzaro″ Università di Palermo and INSTM-Udr Palermo Centro Grandi Apparecchiature-UniNetLab, Università di Palermo 5 Dipartimento di Chimica, Università di Sassari and INSTM-Udr Sassari e_kraleva@yahoo.com
Ключевые слова: TiO2-ZrO2 mixed oxides, sol-gel method, srilankite, Rietveld method
Страницы: 340-348
Аннотация
Pure titania, zirconia, and mixed oxides (3-37 mol.% of ZrO2) are prepared using the sol-gel method and calcined at different temperatures. The calcined samples are characterized by Raman spectroscopy, X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption porosimetry. Measurements reveal a thermal stability of the titania anatase phase that slightly increases in the presence of 3-13 mol.% of zirconia. Practically, the titania anatase-rutile phase transformation is hindered during the temperature increase above 700 °C. The mixed oxide with 37 mol.% of ZrO2 treated at 550 °C shows a new single amorphous phase with a surface area of the nanoparticles double with respect to the other crystalline samples and the formed srilankite structure (at 700 °C). The anatase phase is not observed in the sample containing 37 mol.% of ZrO2. The treatment at 700 °C causes the formation of the srilankite (Ti0.63Zr0.37Ox) phase.
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