Li Shuai, Lu Xia, Shi Siqi, Chen Liquan, Wang Zhaoxiang, Zhao Yusheng
Department of Physics, Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China.
Shenzhen Key Laboratory of Solid State Batteries, Guangdong Provincial Key Laboratory of Energy Materials for Electric Power, Southern University of Science and Technology, Shenzhen, China.
Front Chem. 2020 May 25;8:348. doi: 10.3389/fchem.2020.00348. eCollection 2020.
CeO-based materials have been studied intensively as anodes for intermediate temperature solid oxide fuel cells (IT-SOFCs). In this work, pristine and europium (Eu)-doped CeO nanowires were comprehensively investigated as anode materials for IT-SOFCs, by a combination of theoretical predictions and experimental characterizations. The results demonstrate: (1) Oxygen vacancies can be energetically favorably introduced into the CeO lattice by Eu doping; (2) The lattice parameter of the ceria increases linearly with the Eu content when it varies from 0 to 35 .%, simultaneously resulting in a significant increase in oxygen vacancies. The concentration of oxygen vacancies reaches its maximum at a ca. 10 .% Eu doping level and decreases thereafter; (3) The highest oxygen ion conductivity is achieved at a Eu content of 15 .%; while the 10 .% Eu-doped CeO sample displays the highest catalytic activity for H-TPR and CO oxidization reactions. The conducting and catalytic properties benefit from the expanded lattice, the large amount of oxygen vacancies, the enhanced reactivity of surface oxygen and the promoted mobility of bulk oxygen ions. These results provide an avenue toward designing and optimizing CeO as a promising anode for SOFCs.
基于CeO的材料作为中温固体氧化物燃料电池（IT - SOFCs）的阳极受到了广泛研究。在这项工作中，通过理论预测和实验表征相结合的方式，对原始的和铕（Eu）掺杂的CeO纳米线作为IT - SOFCs的阳极材料进行了全面研究。结果表明：（1）通过Eu掺杂可以在能量上有利地将氧空位引入CeO晶格中；（2）当氧化铈的Eu含量从0变化到35.%时，其晶格参数随Eu含量线性增加，同时导致氧空位显著增加。氧空位浓度在约10.%的Eu掺杂水平时达到最大值，此后降低；（3）在Eu含量为15.%时实现了最高的氧离子电导率；而10.% Eu掺杂的CeO样品对H - TPR和CO氧化反应表现出最高的催化活性。导电和催化性能得益于晶格的扩大、大量的氧空位、表面氧反应性的增强以及体相氧离子迁移率的提高。这些结果为设计和优化CeO作为SOFCs的有前景的阳极提供了一条途径。
