确定电化学调节的LiCoO2的活性表面,用于氧气演化反应
Zhiyi Lu1, Guangxu Chen1, Yanbin Li1
1Department of Material Science and Engineering, Stanford University , Stanford, California 94305, United States.
Journal of the American Chemical Society
|April 19, 2017
概括
在氧化物 (LCO) 上的边缘位置是氧化演化反应 (OER) 催化的关键. 电化学脱 (De-LCO) 通过暴露这些活性边缘部位而不是基底 (0001) 表面来增强OER活性.
科学领域:
- 材料科学
- 电化学
- 催化剂
背景情况:
- 识别活性位点对于设计高效的催化剂至关重要.
- 层状氧化物 (LCO) 是一种有趣的催化应用材料.
- 氧化演化反应 (OER) 是许多电化学系统中的一个关键过程.
研究的目的:
- 调查OER的LCO的活性表面.
- 了解电化学解 (De-LCO) 对LCO的OER活动的影响.
- 将理论预测与有关LCO表面活动的实验观测联系起来.
主要方法:
- 预测不同LCO表面的OER活动的理论计算.
- 电化学分离LCO.
- 用于OER的LCO纳米片和纳米颗粒的实验性表征.
- 用酸蚀刻LCO来改变表面的特性.
主要成果:
- 在LCO的稳定 (0001) 表面显示高的OER超电位,独立于含量.
- 预计边缘区域,特别是 (112̅0) 和 (011̅2) 表面对OER非常活跃,对 (脱) 石化很敏感.
- 实验结果显示LCO纳米片 (暴露 (0001) 表面) 的OER增强值微不足道,但LCO纳米颗粒 (暴露边缘) 的增强值显著.
- 用酸蚀刻LCO创建更多的边缘区域改善了OER活动,支持理论发现.
结论:
- 在LCO上的OER活动主要由边缘区域决定,而不是基底 (0001) 表面.
- 通过增加活性CO4+位点的比例和转移氧2p状态,电化学脱增强了OER.
- 表面工程,例如创建更多的边缘站点,是一种可行的策略,以提高LCO对OER的催化性能.
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