材料工程  2017, Vol. 45 Issue (9): 72-80   PDF    
http://dx.doi.org/10.11868/j.issn.1001-4381.2016.001320
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文章信息

史艳华, 赵杉林, 王玲, 梁平, 关学雷
SHI Yan-hua, ZHAO Shan-lin, WANG Ling, LIANG Ping, GUAN Xue-lei
稀土Ce掺杂纳米晶Mn-Mo-Ce氧化物阳极及其选择电催化性能
Nanocrystalline Mn-Mo-Ce Oxide Anode Doped Rare Earth Ce and Its Selective Electro-catalytic Performance
材料工程, 2017, 45(9): 72-80
Journal of Materials Engineering, 2017, 45(9): 72-80.
http://dx.doi.org/10.11868/j.issn.1001-4381.2016.001320

文章历史

收稿日期: 2016-11-07
修订日期: 2017-03-31
稀土Ce掺杂纳米晶Mn-Mo-Ce氧化物阳极及其选择电催化性能
史艳华 , 赵杉林, 王玲, 梁平, 关学雷    
辽宁石油化工大学 机械工程学院, 辽宁 抚顺 113001
摘要: 采用阳极电沉积技术制备纳米晶Mn-Mo-Ce氧化物阳极,利用SEM,EDS,XRD,HRTEM,电化学等检测技术及析氧效率测试方法研究氧化物阳极的纳米结构和选择电催化性能,探讨析氧抑氯选择电催化的机理。结果表明:少量Ce掺杂获得了具有网孔状纳米结构的Mn-Mo-Ce氧化物阳极,该阳极在海水中具有99.51%析氧效率的高效选择电催化性能。由于γ-MnO2结构特性优先吸附OH-,抑制Cl-吸附,OH-在Mn4+/Mn3+变价电催化作用下完成析氧,实现选择电催化过程;Ce掺杂增加反应活性,促进吸附与放电过程;活性(100)晶面的晶面间距增大促进OH-的流动和新生O2的逸出,从纳米形貌效应上实现高效析氧抑氯选择电催化性能。
关键词: Mn-Mo-Ce氧化物    稀土掺杂    阳极电沉积    选择电催化   
Nanocrystalline Mn-Mo-Ce Oxide Anode Doped Rare Earth Ce and Its Selective Electro-catalytic Performance
SHI Yan-hua , ZHAO Shan-lin, WANG Ling, LIANG Ping, GUAN Xue-lei    
School of Mechanical Engineering, Liaoning Shihua University, Fushun 113001, Liaoning, China
Abstract: The anode oxide of nanocrystalline Mn-Mo-Ce was prepared by anode electro-deposition technology, and its nanostructure and selective electro-catalytic performance were investigated using the SEM, EDS, XRD, HRTEM, electrochemical technology and oxygen evolution efficiency testing. Furthermore, the selective electro-catalytic mechanism of oxygen evolution and chlorine depression was discussed. The results show that the mesh-like nanostructure Mn-Mo-Ce oxide anode with little cerium doped is obtained, and the oxygen evolution efficiency for the anode in the seawater is 99.51%, which means a high efficiency for the selective electro-catalytic for the oxygen evolution. Due to the structural characteristics of γ-MnO2, the OH- ion is preferentially absorbed, while Cl- absorption is depressed. OH- accomplishes the oxygen evolution process during the valence transition electrocatalysis of Mn4+/Mn3+, completing the selective electro-catalysis process. Ce doping greatly increases the reaction activity, and promotes the absorption and discharge; the rising interplanar spacing between active (100) crystalline plane promotes OH- motion and the escape of newborn O2, so that the selective electro-catalytic property with high efficient oxygen evolution and chlorine depression is achieved from the nano morphology effect.
Key words: Mn-Mo-Ce oxide    rare earth doped    anodic deposition    selective electro-catalytic   

电解海水氢能开发应用中,最理想的析氧抑氯阳极材料是过渡族元素Mn的二元或三元复合氧化物,其中以阳极沉积制备的γ-MnO2物相结构Mn-Mo氧化物及其基础上开发的Mn-Mo-Fe,Mn-Mo-V等氧化物最为成熟,在碱性海水介质中具有95%以上析氧的高效选择电催化性能[1-3]。Mn系氧化物由于其结构具有较大的隧道空间和比表面积、高的晶格氧浓度等而具有高的电催化性能[4-6],元素掺杂和纳米化是提高Mn系氧化物阳极电催化性能的重要途径[7-9]。但Mn的氧化物阳极的电催化稳定性有待进一步提高,而且其选择电催化的机理也少有报道。稀土元素具有未充满的4f层电子结构,可以产生多种电子能级;具有大的原子磁矩、很强的自旋轨道耦合,使其具有独特的光、电、磁等物理化学性质,有“工业味精”之称,极少量的加入就可改善性能,在众多高新材料领域受到高度关注[10, 11]。研究表明:电沉积技术是稀土实现其功能性的重要途径,阴极电沉积复合CeO2和La2O3等稀土氧化物或阳极电沉积CeO2