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为探究纳米钙钛矿型复合氧化物ABO3中不同B位元素及Cu的掺杂量对催化剂的结构、形貌、表面性质和催化活性的影响规律及原因,并优化出具有更好活性的催化剂,采用柠檬酸-溶胶-凝胶法制备得到8个钙钛矿型复合氧化物Y0.7Ce0.1Sr0.2Fe1-xCuxO3和Y0.7Ce0.1Sr0.2Mn1-xCuxO3(x=0.1~0.4),通过X射线衍射(XRD)、扫描电镜(SEM)、比表面积(BET)、X射线光电子能谱(XPS)等分析方法对其进行了表征,并测试了8个样品对CO+NO的催化活性。结果表明,在Fe、Mn两个系列中,x=0.3时的两个样品对CO+NO分别具有最高的催化活性,Y0.7Ce0.1Sr0.2Fe0.7Cu0.3O3对NO和CO的转化率均在225℃时达到100%,而Y0.7Ce0.1Sr0.2Mn0.7Cu0.3O3对NO和CO的转化率则分别在325℃和225℃时达到100%。Y0.7Ce0.1Sr0.2Fe0.7Cu0.3O3的催化活性优于Y0.7Ce0.1Sr0.2Mn0.7Cu0.3O3,这是由于Fe4+/Fe3+的摩尔比高于Mn4+/Mn3+,并且Y0.7Ce0.1Sr0.2Fe0.7Cu0.3O3中所有Ce4+/Ce3+、Cu+/Cu2+和OA/OL的摩尔比均高于Y0.7Ce0.1Sr0.2Mn0.7Cu0.3O3中相应的摩尔比,而这些因素均有利于NO+CO的催化活性。通过适量的Cu取代B位离子可提高催化剂对NO+CO的氧化还原性,同时Cu的掺杂对于Fe、Mn两个系列中OA/OL的摩尔比具有不同的影响。
In order to explore the rules and causes of the structure, morphology, surface properties and catalytic activity of different B-site elements and Cu in nano-perovskite composite oxide ABO3 and optimize the catalyst with better activity , Eight perovskite-type composite oxides Y0.7Ce0.1Sr0.2Fe1-xCuxO3 and Y0.7Ce0.1Sr0.2Mn1-xCuxO3 (x = 0.1-0.4) were prepared by citric acid-sol-gel method. XRD, SEM, BET, XPS and other analytical methods were used to characterize the catalytic activity of 8 samples for CO + NO. The results show that the two samples have the highest catalytic activity for CO + NO in the two series of Fe and Mn, respectively. The conversion of NO and CO for Y0.7Ce0.1Sr0.2Fe0.7Cu0.3O3 Reached 100% at 225 ° C, whereas the conversion of NO and CO at Y0.7Ce0.1Sr0.2Mn0.7Cu0.3O3 reached 100% at 325 and 225 ° C, respectively. The catalytic activity of Y0.7Ce0.1Sr0.2Fe0.7Cu0.3O3 is superior to that of Y0.7Ce0.1Sr0.2Mn0.7Cu0.3O3 because the molar ratio of Fe4 + / Fe3 + is higher than that of Mn4 + / Mn3 + and Y0.7Ce0.1Sr0. The molar ratios of Ce4 + / Ce3 +, Cu + / Cu2 + and OA / OL in 2Fe0.7Cu0.3O3 are all higher than the corresponding molar ratios in Y0.7Ce0.1Sr0.2Mn0.7Cu0.3O3, and these factors are in favor of NO + CO Catalytic activity. The amount of Cu replaced by B ions can improve the catalyst of NO + CO redox, while Cu doping for Fe, Mn two series of OA / OL molar ratio has a different impact.