在双修改的Au表面上进行过氧化物电还原:振动光谱和密度函数计算
1Department of Chemistry and Fredrick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Journal of the American Chemical Society
|June 5, 2003
概括
澄清了对 bismuth 修饰黄金表面的过氧化物的电还原. 木-基物种是过氧化物电还原中的关键中间体,其活性取决于木原子间距.
科学领域:
- 电化学 电化学 电化学
- 表面科学是一门学科.
- 计算化学计算化学
背景情况:
- 了解过氧化物电还原对于各种电化学应用至关重要.
- 探讨了对电极表面的木修饰的催化活性.
- 特定表面物种在反应机制中的作用需要详细研究.
研究的目的:
- 为了阐明 bismuth-submonolayer-modified Au(111) 表面上过氧化物电还原的机制.
- 调查土覆盖面和阿达托姆间距对催化活性的影响.
- 确定参与电还原过程的关键中间物种.
主要方法:
- 用表面增强的拉曼散射 (SERS) 测量来识别表面物种.
- 进行密度函数理论 (DFT) 计算,以建模反应路径和能量.
- 电化学实验在Au(111) 表面上进行,这些表面经过修改,覆盖了不同种 bismuth.
主要成果:
- 通过SERS光谱检测出水氧化物 (Bi-OH) 和氧化物 (Bi-O) 的物种,其潜力与过氧化物减少有关.
- DFT计算显示,过氧化物在催化活性 (2x2) Bi/Au111) 表面相对于Bi-OH是不稳定的.
- 观察到对子单层石覆盖物的催化活性,对全石单层的不活性行为,与 adatom 间距相关.
结论:
- 这项研究表明,甲-氧化物 (M-OH) 种在过氧化物的电还原中发挥着关键作用.
- 催化活性在很大程度上取决于 bismuth adatoms 在 Au ((111) 表面的特定配置和间距.
- 这些发现为改造的电极表面的过氧化电还原机制提供了基本的见解.
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