Structure and properties of bifunctional catalysts based on zirconia modified by tungsten oxide obtained by polymeric precursor method

Bifunctional catalysts of Pt/WOx–ZrO2 (PWZ) type with 1 wt% of Pt and 10, 15 and 20 wt% of tungsten were synthesized by polymeric precursor method and after they were calcined at 600, 700 and 800 °C. The structural and textural properties of the catalysts were by X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), N2 adsorption measurement, temperature programmed reduction by derivative thermogravimetry (TPR–DTG) and transmission electron microscopy (TEM). X-ray diffractogram revealed the presence of tetragonal ZrO2 and platinum (Pt) as the main phases. The infrared spectra of the catalysts showed bands due O–W–O and WO bonds. The catalysts showed specific surface area values in the range of 30–160 m2 g−1. TPR profile showed reduction peaks at high temperatures that were related with the reduction of WOx species. Such catalysts were active in the n-heptane isomerization with high selectivity to branched product.

Bifunctional catalysts of Pt/WOx–ZrO2 (PWZ) type with 1 wt% of Pt and 10, 15 and 20 wt% of tungsten were synthesized by polymeric precursor calcined at 600, 700 and 800 °C and characterized by several techniques. Such catalysts were active in the n-heptane isomerization with high selectivity to branched product.Figure optionsDownload as PowerPoint slide