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通过电化学潜能提高氧气还原活性和稳定性在矿氧化物表面
Sanaz Koohfar1,2, Masoud Ghasemi3,4, Tyler Hafen5
1Laboratory for Electrochemical Interfaces, Massachusetts Institute of Technology, Cambridge, MA, USA.
Nature communications
|November 8, 2023
概括
应用正极电位可以通过稳定表面化学和增强氧降低电化学活性来提高固体氧化物电化学细胞中氧气电极的耐用性.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 表面化学 表面化学
背景情况:
- 过渡金属氧化物矿中的表面化学不稳定性限制了固体氧化物电化学电池中的氧电极的长期耐用性.
- 这种不稳定性主要是由从矿晶格到表面的A位点剂分离引起的.
研究的目的:
- 研究正极电位对氧电极稳定性和电化学活性的影响.
- 了解由阴极电位诱导的表面和地下化学和结构变化.
主要方法:
- 从La1-xSrxCo1-xFexO3与Sm0.2Ce0.8O1.9混合而成的多孔电极的制造.
- 在操作过程中应用正极电位.
- 使用X射线光电子光谱学 (XPS) 和二次离子质谱学 (SIMS) 进行表面和地表分析.
主要成果:
- 阴极潜力显著提高了氧降解反应的稳定性和电化学活性.
- 表面附近的矿区的分解导致了鲁德尔斯登-波珀阶段的形成.
- 观察到抑制A位点剂分离,并将催化活性 (Co) 颗粒溶解到表面.
结论:
- 阴极潜能是一种有效的方法,可以产生理想的表面化学物质,以实现稳定和活跃的氧气减少.
- 拉德尔斯登 - 波珀相的形成和溶解的Co粒子是维持表面活动的关键因素.
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