一个由N-Doped石墨碳电催化氧降解反应的pH依赖选择性模型
Benjamin W Noffke1, Qiqi Li1, Krishnan Raghavachari1
1Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
Journal of the American Chemical Society
|October 14, 2016
概括
用添加的碳材料催化氧降解反应 (ORR). 一个新的模型解释了基于界面溶解的ORR选择性,在性条件下偏好四电子路径.
科学领域:
- 电化学
- 材料科学
- 催化剂
背景情况:
- 用添加的石墨碳材料是氧降解反应 (ORR) 的催化剂的有希望的替代品.
- 了解这些材料的催化机制和选择性决定因素至关重要.
- 目前关于化碳材料的ORR选择性的知识有限.
研究的目的:
- 阐明在化石墨碳材料中控制ORR选择性的催化机制.
- 提出一个理论模型来解释观察到的pH依赖ORR选择性.
- 合理化这些先进材料中ORR选择性的实验发现.
主要方法:
- 在模型石墨烯纳米结构上进行ORR选择性的理论计算.
- 理论预测与实验结果的比较.
- 基于界面溶解效应的模型的开发.
主要成果:
- 一个基于界面溶解的模型成功地解释了性电解质中的四电子ORR路径的偏好.
- 活动部位周围的疏水环境阻碍了水的进入,并使过氧化物中间体不稳定.
- 该模型准确地预测了酸性电解质向两电子通路的转移,与实验数据一致.
结论:
- 表面溶解是决定氧化碳材料ORR选择性的关键因素.
- 拟议的模型为pH依赖的ORR选择性提供了统一的解释.
- 这种机制的理解可以指导用于能源应用的更高效的电催化剂的设计.
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