V2O5-Sb2O3-TiO2催化剂 低温NH3还原NO及其抗H2O和SO2毒化性能

浸渍法制备了催化剂V₂O₅-Sb₂O₃-TiO₂,考察了V₂O₅、Sb₂O₃负载量、pH值和焙烧温度对催化剂V₂O₅- Sb₂O₃-TiO₂低温氨选择性催化还原(SCR)NO活性的影响;同时,考察了催化剂V₂O₅-Sb₂O₃-TiO₂抗H₂O和SO₂毒化性能。结果表明,V₂O₅和Sb₂O₃负载量分别为5%和2%、焙烧温度为400℃、pH值为4时,催化剂SCR活性最好,反应温度220℃时,可达97%。Sb₂O₃的加入不仅能增强V₂O₅/TiO₂的催化活性,而且能明显提高催化剂的抗H₂O和SO₂毒化性能。SO₂、NO吸附暂态反应和TG-DTG测试表明,Sb₂O₃的促进机制主要是促进了催化剂在SO₂存在条件下对NO的吸附,同时,减弱了硫酸铵盐与催化剂之间的相互作用,硫酸铵盐更容易分解。

Selective catalytic reduction of NO with ammonia overV2O5-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.