在氧演化反应中识别氧含量丰富的CO3的动态行为
Zhaohui Xiao1, Yu-Cheng Huang2, Chung-Li Dong2
1State Key Laboratory of Chem/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China.
Journal of the American Chemical Society
|June 16, 2020
概括
在氧化物 (Co3O4) 电催化剂中的氧空隙通过促进位在催化过程中的表面重建和预氧化来加速氧化演变反应 (OER).
科学领域:
- 材料科学
- 电化学
- 催化剂
背景情况:
- 过渡金属化合物中缺陷结构对氧演化反应 (OER) 的作用尚不清楚.
- 在操作条件下了解缺陷部位的动态行为对于阐明反应机制至关重要.
研究的目的:
- 在电催化OER过程中调查Co3O4中缺陷机制和缺陷部位的动态行为.
- 为了比较纯斯宾尔CO3O4与富含氧气空位 (VO) 的CO3O4作为催化剂模型.
主要方法:
- 使用电化学阻抗光谱 (EIS) 和循环电压测量 (CV).
- 使用了近操作式X射线光电子光谱 (XPS) 和操作式X射线吸收细结构 (XAFS).
主要成果:
- 氧气空缺 (VO) 在较低的电位下促进低价值 (CO2+) 的预氧化.
- 在OER启动之前,富含VO的CO3O4经历了表面重建.
- 用基物种 (OH•) 填充氧气空缺,促进预氧化和中间Co-OOH•重建.
结论:
- 缺陷工程,特别是氧气空缺,在OER的CO3O4电催化中发挥着动态作用.
- 这些发现提供了关于缺陷电催化剂表面和活性位点的动态演变的见解.
- 这项研究鼓励进一步研究缺陷电催化剂的动态行为,以提高OER性能.
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