在Ni/Fe (氧) 氧化物中的反应性Fe位点对异常的氧气电催化活性负责
Michaela Burke Stevens1, Christina D M Trang1, Lisa J Enman1
1Department of Chemistry and Biochemistry, University of Oregon , Eugene, Oregon 97403, United States.
Journal of the American Chemical Society
|August 10, 2017
概括
-铁氧化催化剂中的铁显著增加了氧化演化反应 (OER) 的活性. 这种增强源于局部缺陷的铁,而不是散装替代,强调了具体结构安排的重要性.
科学领域:
- 电化学
- 材料科学
- 催化剂
背景情况:
- -铁氧化 (Ni(Fe) OxHy) 是氧化演化反应 (OER) 的高活性催化剂.
- 铁 (Fe) 在提高OER性能中的确切作用尚不完全理解.
- 了解Fe的功能对于设计更高效的电催化剂至关重要.
研究的目的:
- 阐明不同铁物种在Ni (Fe) OxHy催化剂中的不同作用.
- 确定散装或局部化Fe是否有助于增强开放式资源活动.
- 为了澄清 Fe 结合,Ni 电量测量和催化性能之间的关系.
主要方法:
- 合成和表征NiOxHy材料.
- 电化学测量,包括循环电压测量,以评估OER活动.
- 分析以区分散装和表面/缺陷相关的Fe物种.
主要成果:
- 确定了两种类型的Fe物种:在边缘/缺陷上快速集成的Fe和大量的Fe替代Ni.
- 快速结合的Fe物种直接导致了增强的OER活动.
- 大量Fe替代影响观察到的电量测量,但不影响内在的OER增强.
结论:
- 特殊的OER活性是由于Fe在局部部位 (边缘/缺陷),而不是Fe在散装中被替代.
- 大量离子的电位特征不仅解释了催化剂的高性能.
- 局部原子结构和缺陷点是Ni(Fe) OxHy中优质OER催化的关键因素.
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