表面质子转移促进了溶液中的金纳米晶表面的四电子氧降低
Fang Lu1, Yu Zhang2, Shizhong Liu2
1Center for Functional Nanomaterials, Energy & Photon Sciences Directorate, Brookhaven National Laboratory , Upton, New York 11973, United States.
Journal of the American Chemical Society
|May 12, 2017
概括
研究人员发现了一种新的黄金表面 ({310}),可以有效地催化四电子氧降解反应 (4e-ORR). 这一发现有助于理解表面结构如何影响能量转化中的催化活性.
科学领域:
- 电化学
- 材料科学
- 催化剂
背景情况:
- 四个电子的氧降解反应 (4e-ORR) 对于高效的能量转化至关重要,超越了两个电子路径的有限的氧解离.
- 黄金表面在ORR中对原子结构具有很高的敏感性,之前在狭窄的潜在窗口中为4e-ORR记录了{100}个方面.
研究的目的:
- 在不同的金纳米晶体面,特别是{310}表面上研究ORR路径.
- 了解性溶液中黄金上的面依赖性4e-ORR活性背后的机制.
主要方法:
- 对具有特定面向的金纳米晶体进行实验研究 (例如,截断的二三角镜 - TDP).
主要成果:
- 在TDP型Au纳米晶体的 {310} 表面上观察到整个潜在范围的4e-ORR.
- 其他面的ORR路径 (在纳米八面体上{111},在纳米立方体上{100}) 反映了它们的单晶对应物.
- 密度函数理论 (DFT) 的计算揭示了由共同吸收的水分子的表面质子转移的关键作用.
结论:
- 表面原子结构通过影响键分裂和水和中间体的形成来决定ORR路径.
- 从水中的质子转移是激活性介质中的黄金面和电位依赖的4e-ORR的关键.
- 这为设计面特异性纳米催化剂提供了可增强的能量转化反应的见解.
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