V2O5/Nb2O5, V2O5/Al-x and V2O5/TiO2 and promoted Ni-Nb-M-O (M=Cr, Mo, W) catalysts were prepared by impregnation and evaporation methods, respectively. All these catalysts were characterized by several physico-chemical techniques. The catalytic performance of these solids was evaluated towards the ODHE in a fixed bed quartz reactor at 500-600 °C for supported vanadia samples and 300-450 °C for Ni-Nb-M-O catalysts. Special emphasis is devoted to gain deeper insights on the physico-chemical characteristics of the catalysts in relation to their activity/selectivity properties.