载体对铜基催化剂NH_3-SCR低温脱硝性能的影响

采用浸渍法制备载体负载铜氧化物催化剂。通过XRD、TG-MS、XPS、NO-TPD、NH_3-TPD和H_2-TPR等手段对催化剂进行表征,考察了有氧条件下载体对催化剂NH_3-SCR低温脱硝性能的影响。结果表明,铜物种在载体上以CuO和Cu_2O形式共存,载体影响铜物种的分散性和氧化态,影响催化剂酸性、氧化还原性和对反应物的吸脱附能力。Cu/HZSM-5催化剂,铜物种分散度高,氧化还原性能好,具有适宜的酸性和酸量,对反应物有良好的吸附-脱附性能,在NH_3-SCR脱硝反应中具有较好的催化活性,反应温度低,T_(50)和T_(90)分别为137和165℃,活性窗口温度宽,NO转化率高于90%的温度为165-358℃。

Effect of carrier on the performance of copper based catalyst for selective catalytic reduction of NO with NH3 at low temperature

The catalysts of supported copper oxide were prepared by impregnation method, which were characterized by XRD, TG-MS, XPS, NO-TPD, NH₃-TPD and H₂-TPR and the effect of carrier on the performance of catalysts for the selective catalytic reduction of NO with NH₃ at low-temperature in the presence of oxygen was investigated.The results show that the copper species exist in the form of CuO and Cu₂O on carriers.The dispersion and oxidation state of copper species, the acidity and redox ability of the catalysts and the performance of adsorption/desorption are affected by the carriers.The Cu/HZSM-5 catalyst with highly dispersed copper speicies has excellent redox properties, suitable acidity and acid capacity, and good adsorption/desorption performance for reactants, which shows a good catalytic activity in the NH₃-SCR denitrification reaction.The reaction temperature is lower, T₅₀ and T₉₀ is 137 and 165℃, respectively, and the active window temperature is wide.The temperature range for the NO conversion of over 90% is 165-358℃.