制备方法对V_2O_5-WO_3/TiO_2选择性催化还原催化剂性能的影响

采用共沉淀法、溶胶-凝胶法和浸渍法制备了V2O5质量分数4%和WO3质量分数6%的V2O5-WO3/TiO2选择性催化还原催化剂,对比了3种方法制备的催化剂选择性催化还原NO性能。采用X射线衍射、热重、N2吸附-脱附和程序升温还原等对制备的V2O5-WO3/Ti O2催化剂的结构和性质进行表征,结果表明,共沉淀法制备的V2O5-WO3/TiO2催化剂具有更好的选择性催化还原NO活性和更大的比表面积,影响共沉淀法选择性催化还原NO活性的主要因素是催化剂的热稳定性、表面羟基数量、比表面积、粒径分布以及V、W与Ti之间的内在作用。

Influence of preparation methods on the performance of V2 O5-WO3/TiO2 catalysts for NO selective catalytic reduction

V₂O₅-WO₃/TiO₂ selective catalytic reduction(SCR) catalysts with mass fraction of V₂O₅ 4% and WO₃ 6% were prepared by co-precipitation,sol-gel and impregnation methods,respectively.The activities of the catalysts prepared by the three methods for selective catalytic reduction of NO were investigated.The catalysts were characterized by X ray diffraction,thermo gravimetric analyzer,N2 adsorption-desorption and temperature programmed reduction.The results indicated that compared with the catalysts prepared by sol-gel and impregnation methods,V₂O₅-WO₃/TiO₂ catalyst prepared by co-precipitation method exhibited better SCR activity and possessed larger surface area.The activity of the catalyst prepared by co-precipitation for NO selective catalytic reduction related to its thermal stability,surface hydroxyl groups amount,surface area,pore size distribution and the interaction among V,W and Ti.