A series of zirconium-doped nano-titania (Zr/TiO(2)) with various amounts of Zr were prepared by sol-gel method using titanium(iv) isopropoxide and zirconium nitrate as precursors. Zr/TiO(2) samples were characterized using X-ray diffraction (XRD), surface area-pore volume measurements, infrared (FTIR) spectroscopy, UV-vis-diffuse reflectance spectroscopy (UV-vis-DRS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, thermogravimetric (TG) analysis, and transmission electron microscopy (TEM) techniques. XRD data and Raman spectra indicated that even after 5 mol% doping of zirconium in the crystal lattice of TiO(2), the samples were phase pure with the anatase structure. The crystalline size of the anatase decreased with increasing Zr content. An increase in the BET surface area was also observed after doping of zirconium on nano-titania.

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The performance of vanadia-doped zirconia-pillared clay (V/Zr-PILC) for the selective catalytic oxidation of H 2 S was investigated in this study. A series of vanadia-doped zirconia pillared clays (V/Zr-PILCs) with various amounts of vanadia were prepared and characterized using X-ray diffraction (XRD), surface area-pore volume measurements, chemical analysis, infrared (FTIR) spectroscopy, UV-vis-diffuse reflectance spectroscopy (UV-vis-DRS), X-ray photoelectron spectroscopy (XPS), and thermogravimetric (TG) analysis. V/Zr-PILCs showed better catalytic performance than Zr-PILC at temperatures ranging from 220-300 C without any considerable SO 2 emission. The H 2 S conversion over V/Zr-PILCs increased with increasing vanadia content up to 6 wt%. However, it decreased at higher vanadia loadings due to the decrease of surface area and to the formation of the crystalline V 2 O 5 phase. The results of a regeneration experiment using 6 wt% V/Zr-PILC catalyst showed good reproducibility in its catalytic activity, even through five successive sulfidation-regeneration cycles at 280 C.

A series of vanadia-doped iron-oxide-pillared clays (V/Fe-PILCs) with various amounts of vanadia were prepared and their performance for the selective catalytic oxidation of H(2)S was investigated. V/Fe-PILCs were characterized using X-ray diffraction (XRD), surface area- and pore volume measurements, chemical analysis, Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction by H(2) (H(2)-TPR). V/Fe-PILCs showed better catalytic performance than Fe-PILC without any significant SO(2) emissions. The H(2)S conversion over V/Fe-PILCs increased with increasing vanadia content up to 7 wt.%. However, it decreased at higher vanadia loading due to the decrease in surface area and the formation of the crystalline V(2)O(5) phase. The presence of water vapor in the reactant mixture resulted in a decrease of H(2)S conversion.

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