以MnO2为活性组分,Fe2O3为助剂,制备了以TiO2及ZrO2-TiO2为载体的整体式催化剂.考察了它们在不同温度焙烧后应用于富氧条件下,NH3选择性催化还原(NH3-SCR)氮氧化物的低温反应性能和高温稳定性.用X射线衍射(XRD)实验、比表面积测定(BET)、储氧性能测定(OSC)及程序升温还原(H2-TPR)等方法对催化剂进行了表征.结果表明,以ZrO2-TiO2为载体的催化剂具有很好的高温热稳定性,并具有较高的比表面积和储氧能力,同时具有较强的氧化能力.催化剂的活性测试结果表明,以ZrO2-TiO2为载体的整体式锰基催化剂明显地提高了NH3-SCR反应的低温活性,具有良好的应用前景.
Monolith catalysts were prepared using TiO2 and ZrO2-TiO2 as supports with MnO2 as active component and Fe2O3 as promoter. The catalytic activities at low temperature and stability at high temperature for selective catalytic reduction of NOx with NH3 (NH3-SCR) in the presence of excessive O2 were studied after the catalysts calcined at different temperatures. The catalysts were characterized by X-ray diffraction (XRD), specific surface area measurements (BET), oxygen storage capacity (OSC), and temperature programmed reduction (H2-TPR). The results indicated that the catalyst supported on ZrO2-TiO2 had excellent stability at high temperature, and possessed high specific surface area and oxygen storage capacity, and had strong redox property. The results of the catalytic activities indicated that the monolith manganese-based catalyst using ZrO2-TiO2 as support had evidently improved the activity of NH3-SCR reaction at low temperature, and it showed great potential for practical application.