ZrO2-TiO2-CeO2的制备及其在NH3选择性催化还原NO中的应用

采用共沉淀法制备了载体材料TiO2、ZrO2-TiO2及ZrO2-TiO2-CeO2, 并利用X射线衍射(XRD)实验、比表面积测定(BET)、程序升温脱附(NH3-TPD)、储氧性能测定(OSC)及程序升温还原(H2-TPR)等方法对三种载体材料进行了表征. 结果表明, ZrO2-TiO2-CeO2具有较多的表面强酸位, 并具有一定的储氧性能和较强的氧化还原性能. 以三种材料为载体, 制备了质量分数分别为1%、9%的V2O5、WO3的整体式催化剂. 研究了三种催化剂在富氧条件下用NH3选择性催化还原NO的催化性能. 结果表明, 以ZrO2-TiO2-CeO2为载体的催化剂在反应空速为10000 h-1, 275 ℃时, NO的转化率接近100%, 具有最好的催化活性,并有良好的应用前景。

Prepareration of ZrO2-TiO2-CeO2 and Its Application in the Selective Catalytic Reduction of NO with NH3

TiO2, ZrO2-TiO2, and ZrO2-TiO2-CeO2 were prepared by co-precipitation method and characterized by X-ray diffraction (XRD), specific surface area measurements (BET), temperature-programmed desorption (NH3-TPD), oxygen storage capacity (OSC), and temperature-programmed reduction (H2-TPR). The results showed that ZrO2-TiO2-CeO2 exhibited large number of surface strong acidity, possessed some oxygen storage capacity, and strong redox property. The three materials were used as supports and the monolith catalysts were prepared with 1% (w) V2O5 and 9%(w) WO3 for selective catalytic reduction (SCR) of NO with ammonia in the presence of excessive O2, and the results of catalytic activity showed that the catalyst used ZrO2-TiO2-CeO2 as support yielded nearly 100% NO conversion at 275 ℃ at a gas hourly space velocity (GHSV) of 10000 h-1, and it had the best catalytic activity and showed great potential for practical application.