焙烧温度对CuO/γ-Al_2O_3和CeO_2-CuO/γ-Al_2O_3催化剂NO还原活性的影响

EFFECT OF CALCINATION TEMPERATURE ON C_3H_6-SCR OF NO OVER CuO/γ-Al_2O_3 AND CeO_2-CuO/γ-Al_2O_3

用浸渍法制备了CuO γ Al2O3催化剂和CeO2改性的CeO2 CuO γ Al2O3催化剂,考察了焙烧温度对CuO γ Al2O3和CeO2 CuO γ Al2O3催化剂C3H6还原NO反应活性的影响,以及CeO2的添加量对CeO2 CuO γ Al2O3催化剂C3H6还原NO反应活性的影响。结果表明,在200℃～500℃的焙烧温度范围内,焙烧温度对CuO γ Al2O3催化剂的活性影响很小;在500℃～800℃的焙烧温度范围内,随着焙烧温度的升高CuO γ Al2O3催化剂的活性急剧下降,由XRD物相测定结果可知,归因于对反应表现惰性的尖晶石CuAl2O4相的生成。当焙烧温度为500℃时,CeO2的添加对CuO γ Al2O3催化剂的活性影响很小;当焙烧温度为800℃时,CeO2的添加对CuO γ Al2O3催化剂有明显的助催化作用,当Ce和Cu的摩尔比为1∶10时,NO转化率较为理想。

CuO/γ-Al_2O_3 and CeO_2-CuO/γ-Al_2O_3 catalysts were prepared by impregnation. The effect of calcination temperature on C_3H_6-SCR of NO over CuO/γ-Al_2O_3 and CeO_2-CuO/γ-Al_2O_3 catalysts CeO_2 with different loadings was investigated. The results showed that calcination temperature had little effect on the activity of C_3H_6-SCR of NO over CuO/γ-Al_2O_3 when calcinated from 200?℃ to 500?℃. NO conversion sharply decreased when increasing the calcination temperature from 500?℃ to 800?℃. It could be caused by the formation of CuAl_2O_4, which was confirmed in XRD patterns. The activity of C_3H_6-SCR of NO over CuO/γ-Al_2O_3 catalyst could not be promoted by the addition of CeO_2 calcinated at 500?℃, while could be improved calcinated at 800?℃. The highest NO conversion was achieved while the mole ratio of Ce to Cu was 1∶10.