采用共沉淀法制备了MnOx-CeO2-WO3-ZrO2催化剂,考察了催化剂焙烧温度对O2和H2O存在下NH3选择性催化还原(NH3-SCR) NO的影响,并利用低温N2吸附、X射线衍射(XRD)、透射电镜(TEM)、X射线光电子能谱(XPS)、NH3程序升温脱附(NH3-TPD)和CO脉冲反应对催化剂进行了表征.结果表明在NH3-SCR反应中,催化剂的低温活性随焙烧温度的提高而降低,这是由于催化剂表面化学吸附氧和酸性位减少引起的；催化剂的高温活性随焙烧温度的提高先增加后减小,这与催化剂表面最易释放氧数量的变化趋势相反.700°C焙烧的催化剂具有良好的低温活性和最宽的反应温度窗口,在空速为90000 h-1的条件下,该催化剂的起燃温度(50%NO转化率)为189°C,且反应温度在218-431°C范围内, NO转化率可达到80%-100%.%MnOx-CeO2-WO3-ZrO2 catalysts were prepared by co-precipitation and calcined at various temperatures (500, 600, 700, and 800 ° C). The effect of calcination temperature on their performance in the selective catalytic reduction (SCR) of NO with ammonia in the presence of O2 and H2O was investigated. The structural and physicochemical characterization of the catalysts were performed by N2 adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), NH3 temperature-programmed desorption (NH3-TPD), and CO pulse reaction. The results show that the low temperature activity decreased with an increase in the calcination temperature, which is due to a decrease in the amount of surface chemisorbed oxygen and acid sites. As the calcination temperature increased the high temperature activity first increased and then decreased, which is contrary to the variation found for the most readily releasable oxygen on the catalyst surface. The catalyst calcined at 700 ° C exhibited good low temperature activity and had the widest reaction temperature window. The light-off temperature (50% NO conversion) was 189 ° C for this catalyst and the NO conversion was 80%-100%between 218 and 431 °C at a space velocity of 90000 h-1.
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