气候变化领域集成服务门户(CCPortal): Enhanced oxygen exchange of perovskite oxide surfaces through strain-driven chemical stabilization

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DOI	10.1039/c7ee00770a
	Enhanced oxygen exchange of perovskite oxide surfaces through strain-driven chemical stabilization
	Koo B.; Kwon H.; Kim Y.; Seo H.G.; Han J.W.; Jung W.
发表日期	2018
ISSN	17545692
起始页码	71
结束页码	77
卷号	11 期号:1
英文摘要	Surface cation segregation and phase separation, of strontium in particular, have been suggested to be the key reason behind the chemical instability of perovskite oxide surfaces and the corresponding performance degradation of solid oxide electrochemical cell electrodes. However, there is no well-established solution for effectively suppressing Sr-related surface instabilities. Here, we control the degree of Sr-excess at the surface of SrTi0.5Fe0.5O3-δ thin films, a model mixed conducting perovskite O2-electrode, through lattice strain, which significantly improves the electrode surface reactivity. Combined theoretical and experimental analyses reveal that Sr cations are intrinsically under a compressive state in the SrTi0.5Fe0.5O3-δ lattice and that the Sr-O bonds are weakened by the local pressure around the Sr cation, which is the key origin of surface Sr enrichment. Based on these findings, we successfully demonstrate that when a large-sized isovalent dopant is added, Sr-excess can be remarkably alleviated, improving the chemical stability of the resulting perovskite O2-electrodes. © The Royal Society of Chemistry.
英文关键词	Chemical stability; Conductive films; Degradation; Electrochemical electrodes; Electrodes; Iron compounds; Perovskite; Perovskite solar cells; Phase separation; Positive ions; Solid oxide fuel cells (SOFC); Surface segregation; Titanium compounds; Chemical instability; Chemical stabilization; Compressive state; Electrode surfaces; Experimental analysis; Performance degradation; Solid oxide electrochemical cells; Surface instability; Strontium compounds; electrochemical method; electrode; oxygen; performance assessment; perovskite; reaction kinetics; stabilization; strontium
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/190335
作者单位	Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea; Department of Chemical Engineering, University of Seoul, Seoul, South Korea
推荐引用方式 GB/T 7714	Koo B.,Kwon H.,Kim Y.,et al. Enhanced oxygen exchange of perovskite oxide surfaces through strain-driven chemical stabilization[J],2018,11(1).
APA	Koo B.,Kwon H.,Kim Y.,Seo H.G.,Han J.W.,&Jung W..(2018).Enhanced oxygen exchange of perovskite oxide surfaces through strain-driven chemical stabilization.Energy & Environmental Science,11(1).
MLA	Koo B.,et al."Enhanced oxygen exchange of perovskite oxide surfaces through strain-driven chemical stabilization".Energy & Environmental Science 11.1(2018).