焙烧温度对CuO/γ-Al2O3和CeO2-CuO/γ-Al2O3催化剂NO还原活性的影响
焙烧温度对CuO/γ-Al2O3和CeO2-CuO/γ-Al2O3催化剂NO还原活性的影响
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摘要: 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。Abstract: CuO/γ-Al2O3 and CeO2-CuO/γ-Al2O3 catalysts were prepared by impregnation. The effect of calcination temperature on C3H6-SCR of NO over CuO/γ-Al2O3 and CeO2-CuO/γ-Al2O3 catalysts CeO2 with different loadings was investigated. The results showed that calcination temperature had little effect on the activity of C3H6-SCR of NO over CuO/γ-Al2O3 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 CuAl2O4, which was confirmed in XRD patterns. The activity of C3H6-SCR of NO over CuO/γ-Al2O3 catalyst could not be promoted by the addition of CeO2 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.