Selective catalytic reduction of NO with ammonia over V₂O₅-Sb₂O₃-TiO₂ at low temperature and resistance to H₂O and SO₂ poisoning

The V₂O₅-Sb₂O₃-TiO₂ catalyst was prepared by impregnation method. The influences of V₂O₅and Sb₂O₃ loading, pH value, and calcination temperature on the low temperature selective catalytic reduction (SCR) activities of NO with ammonia over V₂O₅-Sb₂O₃-TiO₂ catalyst were studied. The performance of V₂O₅-Sb-TiO₂ catalyst in resisting the H₂O and SO₂ poisoning was also discussed. The results show that the catalyst has the best SCR activity. When the V₂O₅ and Sb₂O₃ loading is 5% and 2%, respectively, the calcination temperature is 400℃, and the pH value is 4. The NO removal efficiency of 97% is obtained at the reaction temperature of 220℃. The addition of Sb₂O₃ not only strengthens the catalytic activity of V₂O₅-TiO₂, but also improves the resistance to the deactivation by both H₂O and SO₂. The SO₂ and NO adsorption transient response and TG-DTG test demonstrate that the promoting mechanism of Sb₂O₃is mainly to promote the catalyst adsorption of NO, and weaken the interaction between ammonium sulfate and the catalyst, which can result in the decomposition of ammonium sulfate easier.