Abstract  

Catalysts of Pt/WO _x –ZrO₂ type with 1 wt% of Pt and 10, 15 and 20 wt% of tungsten were synthesized and characterized. The structural and morphological features of these catalysts were studied. The samples were synthesized by impregnation method and calcined at 600 °C, 700 °C and 800 °C. The characterizations were carried out using different techniques: X-ray diffraction, Raman spectroscopy, scanning electronic microscopy, nitrogen adsorption measurement and refinement of their crystalline structures by Rietveld method. X-ray diffraction patterns revealed the formation ZrO₂ and WO₃ crystalline structures and its crystallite size were determined. The zirconium oxide crystallized into tetragonal and monoclinic phases and tungsten trioxide crystallized into monoclinic phase. Crystalline WO₃ and amorphous WO _x species were detected by Raman spectra.

Index Abstract  

Catalysts of Pt/WO _x –ZrO₂ type with 1 wt% of Pt and 10, 15 and 20 wt% of tungsten were synthesized and characterized. The structural and morphological features of these catalysts were studied. The samples were synthesized by impregnation method and calcined at 600 °C, 700 °C and 800 °C. The characterizations were carried out using different techniques: X-ray diffraction, Raman spectroscopy, scanning electronic microscopy, nitrogen adsorption measurement and refinement of their crystalline structures by Rietveld method. X-ray diffraction patterns revealed the formation ZrO₂ and WO₃ crystalline structures and its crystalline size were determined. The zirconium oxide crystallized into tetragonal and monoclinic phases and tungsten trioxide crystallized into monoclinic phase. Crystalline WO₃ and amorphous WO _x species were detected by Raman spectra.