V₂O₅/TiO₂ and heteropoly acid promoted V₂O₅/TiO₂ catalysts were prepared and characterized by N₂ physisorption, XRPD and NH₃-TPD. The influence of the calcination temperature from 400 to 700 °C on crystallinity and acidic properties was studied and compared with the activity for the selective catalytic reduction (SCR) of NO with ammonia. The SCR activity of heteropoly acid promoted catalysts was found to be much higher than for unpromoted catalysts. The stability of heteropoly acid promoted catalysts is dependent on calcination temperature and there is a gradual decrease in SCR activity and acidity with increase in calcination temperatures. Furthermore, the heteropoly acid promoted V₂O₅/TiO₂ catalysts showed excellent alkali deactivation resistance and might therefore be alternative deNO_x catalysts in biomass fired power plants.