In the present work the deactivation and the catalytic activity of a TiO2 catalyst used in a Claus process were studied. The techniques employed for catalyst characterization were elemental analysis, X-ray diffraction, scanning electron microscopy, thermic gravimetric and differential thermic analyses, and specific surface area analysis. Also, with the aim of evaluate the deactivation degree in the catalyst; the selective oxidation of hydrogen sulfide at different temperatures was performed. Additionally, spent catalyst samples with different sulfate content were analyzed. The catalyst presented a high degree of thermic degradation, which led to a considerable loss of specific surface area and crystalline phase transition. The sulfates in the TiO2 catalyst increases the selectivity and reaction yield, and provides stability to the catalyst.