摘要
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 investigate the influence of different B cations and the amount of Cu substitution for B on catalyst structure,morphology,surface properties and catalytic activity of the nanoperovskite ABO3,eight nanoscale perovskite- type oxides Y0. 7Ce0. 1Sr0. 2（ Fe,Mn）1- xCuxO3 were prepared by citric acid sol- gel method and characterized by X- ray diffraction（ XRD）,scanning electron microscopy（ SEM）,Brunauer- Emmett- Teller（ BET） and X- ray photoelectron spectroscopy（ XPS）. The results indicate that Y0. 7Ce0. 1Sr0. 2（ Fe,Mn） 0. 7Cu0. 3O3 exhibited best catalytic activities of NO ＋ CO in these two series samples. A better catalytic performance（ 100% NO and CO conversion at 225 ℃） was found over Y0. 7Ce0. 1Sr0. 2Fe0. 7Cu0. 3O3 compared to Y0. 7Ce0. 1Sr0. 2Mn0. 7Cu0. 3O3（ 100% NO and CO conversion at 325 ℃ and 225 ℃ respectively. This may be because the ratio of Fe4 ＋/ Fe3 ＋is higher than Mn4 ＋/ Mn3 ＋. Furthermore,the ratios of Ce4 ＋/ Ce3 ＋,Cu＋/ Cu2 ＋and OA / OL for Y0. 7Ce0. 1Sr0. 2Fe0. 7Cu0. 3O3 are higher than those for Y0. 7Ce0. 1Sr0. 2Mn0. 7Cu0. 3O3,which is beneficial to the reaction of NO and CO. An appropriate amount of Cu substitution for B can promote the reduction and oxidation of NO ＋ CO,and Cu substitution has different effects on the ratio of OA / OL for the two different series.
出处
《稀土》
EI
CAS
CSCD
北大核心
2016年第1期18-26,共9页
Chinese Rare Earths
基金
浙江省自然科学基金(Y5080288)
宁波市自然基金项目(2013A610077)
宁波大学研究生创新基金项目(G14039)
