氧化演化反应过程中矿物质表面演化的动态稳定活性点
Pietro P Lopes1, Dong Young Chung1, Xue Rui2
1Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.
Journal of the American Chemical Society
|January 5, 2021
概括
矿氧化物表现出氧化演化反应 (OER) 活性,这是由于表面的氧化层. 这层与铁杂质相互作用,产生稳定的活性位点,增强催化剂的性能和寿命.
科学领域:
- 材料科学
- 电化学
- 催化剂
背景情况:
- 矿氧化物是性环境中的关键氧化反应催化剂.
- 确定这些催化剂中的精确活性位点仍然是一个重大挑战.
研究的目的:
- 在La1-xSrxCoO3 (LSCO) 矿模型中阐明OER活动的起源和活动地点动态.
- 研究表面演变和电解质相互作用在催化剂性能中的作用.
主要方法:
- 在OER条件下LSCO矿的表面特征.
- 电化学分析以确定活性和稳定性.
- 在现场研究以观察动态活性部位的形成.
主要成果:
- OER活动源于LSCO表面的氧化 (CoOH) 层.
- 电解质中的铁微量与CoOH相互作用,形成动态稳定的活性位点.
- 与纳米级CoOH/LSCO集群相比,CoO/LSCO系统的稳定性增加了10倍,活动稳定性因子提高了3倍.
结论:
- 表面演变,包括A位溶解和O位空的形成,是形成活性CoOH层的关键.
- CoOH层与微量Fe物种之间的相互作用对于稳定和活跃的OER催化是至关重要的.
- 从这些发现可以得出强大的氧化物OER催化剂的新设计原则.
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