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以高锰酸钾和硝酸锰为锰源,采用改进的共沉淀法制备了不同Ce/Mn摩尔比的Ce O2-Mn Ox催化剂.以NH3为还原剂,考察了催化剂低温(小于150℃)NH3选择性催化还原NO的性能.并采用XRD,BET,H2-TPR,NH3-TPD和XPS等手段对催化剂的物理化学性质进行表征.结果表明,Ce O2-Mn Ox催化剂在50~150℃温度区间内表现出了良好的催化活性.引入适量的Ce可以有效地改变催化剂的晶粒大小,增强其氧化还原能力;而Mn的加入,促进了其低温SCR活性.当Ce/Mn摩尔比为1∶3时(C1M3),低温活性最佳,在82~150℃温度区间内NO去除率达到90%以上,这主要是由于C1M3催化剂有较高含量的表面吸附氧、大量的弱酸性位点、良好的氧化还原性能以及表面较高含量的Mn4+物种.
CeO2-MnOx catalysts with different molar ratios of Ce / Mn were prepared by the improved coprecipitation method using potassium permanganate and manganese nitrate as the manganese source.The catalytic activity of the catalyst at low temperature (<150 ℃) NH3 The results showed that the catalytic activity of CeO2-MnOx catalyst in the temperature range of 50-150 ℃ was demonstrated by XRD, BET, H2-TPR, NH3-TPD and XPS. , And the addition of Mn promoted the low-temperature SCR activity.When Ce / Mn molar ratio was 1: 1, At 3 o’clock (C1M3), the activity at low temperature was the best, and the NO removal rate reached more than 90% at the temperature range of 82-150 ℃. This was mainly due to the higher content of surface adsorbed oxygen and a large number of weakly acidic sites on the C1M3 catalyst, Redox properties and higher surface Mn4 + species.