通过Sr装饰改善和降低La0.6Sr0.4CoO3-的氧气交换动力学
Matthäus Siebenhofer1,2, Christoph Riedl1, Andreas Nenning1
1Institute of Chemical Technologies and Analytics, TU Wien Vienna Austria matthaeus.siebenhofer@tuwien.ac.at.
Journal of materials chemistry. A
|June 22, 2023
概括
装饰对固体氧化物燃料电池 (SOFC) 阴极性能产生不同的影响,这取决于沉积条件. 氧化是有益的,而由二氧化碳形成的 SrCO3 对氧气交换动力学是有害的.
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:
- 在空气电极上最大限度地降低过量的电位对于固体氧化物燃料电池 (SOFC) 的适用性至关重要.
- 表面修改提供了一种灵活的方法来增强SOFC阴极表面的氧气交换动力学.
- 表面装饰效应,特别是 (Sr) 的精确机制仍在争论中,之前的发现相互矛盾.
研究的目的:
- 在不同的沉积条件下,研究SOFC阴极氧气交换动力学上的Sr装饰机制.
- 通过检查表面 Sr. 的不同化学环境来解决有关 Sr. 装饰影响的相互矛盾的报告.
主要方法:
- 在现场阻抗光谱与脉冲激光沉积相结合,以研究Sr装饰.
- 近环境压力X射线光电子光谱 (NAP-XPS) 和非环境X射线衍光度 (NA-XRD) 用于化学状态分析.
- 控制的沉积温度变化和气相相互作用.
主要成果:
- 观察到Sr装饰的相反效应,取决于沉积温度和气相相互作用.
- 在高温下,Sr以SrO的形式沉积,有利于影响氧气交换动力学.
- 在低温下,SrCO3从微量CO2中形成吸附物,降低了氧气交换率.
结论:
- 表面Sr的化学环境决定其对氧气交换动力学的影响,SrO是有益的,SrCO是有害的.
- 表面酸度作为表面装饰对SOFC阴极性能影响的描述符.
- 分离本身最初不会降低性能,但分离的很容易与酸性化合物发生反应,降低了催化能力.
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