ZrO_2-TiO_2-CeO_2的制备及其在NH_3选择性催化还原NO中的应用

Prepareration of ZrO_2-TiO_2-CeO_2 and Its Application in the Selective Catalytic Reduction of NO with NH_3

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10000h-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.

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.