Current stringent environmental regulations oblige to treat hydrogen sulphide (H2S) emissions originated in petroleum refineries and gas plants. Claus processes are the most common used, but due to thermodynamic limitations a relevant percentage of H2S is not converted to sulphur in the Claus process [1]. The selective oxidation of hydrogen sulphide by using oxygen from air is necessary [1-2] to avoid the formation of SO2 according to the reaction:H 2 S + ½ O 2 ➝H 2 O + 1/x S x The nature vanadium species, as well as the characteristics of metal oxide support and the catalyst preparation procedure, influence the catalytic performance of vanadium containing catalysts and the catalyst stability [14,15 16], but the nature of active and selective sites well as impregnated or strstructural vanadium is still under discussion V4O9 has been recently proposed [7-16].