合金上的演变反应的电催化活性是由元素特定的吸附点决定的,而不是d波段特性
Maximilian Schalenbach1, Rebekka Tesch2,3, Piotr M Kowalski2,3
1Fundamental Electrochemistry (IEK-9), Institute of Energy and Climate Research, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany. m.schalenbach@fz-juelich.de.
Physical chemistry chemical physics : PCCP
|May 7, 2024
概括
这项研究质疑d波段理论如何解释合金中的演化反应 (HER) 活性. 对于AuPt合金,在吸附点的局部电子效应,而不是d带中心,更好地预测HER性能.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 计算化学计算化学
背景情况:
- 演化反应 (HER) 的电催化活性通常与过渡金属的d波段特性有关.
- 这种d波段理论,侧重于d波段的中心或边缘位置相对于费米水平,当应用于合金时面临挑战.
研究的目的:
- 研究d波段理论的普遍性,以解释HER在过渡金属合金中的活性.
- 以实验和计算方法来研究AuPt合金系统作为一个案例研究.
主要方法:
- 在AuPt合金上进行了电催化测量.
- 密度函数理论 (DFT) 的计算被用来分析电子结构和吸附能.
- 实验 HER 活动与基于 d 波段属性和局部电子效应的理论预测进行比较.
主要成果:
- 纯金属Tafel动力学的线性组合准确地预测了AuPt合金中的HER活动在低超电位时.
- DFT的计算显示,吸附能量在很大程度上独立于邻居,并受到当地的电子密度的影响.
- 反映非局部化的电子的状态的d频段密度,未能捕捉到对HER至关重要的局部键性强度.
结论:
- 这项研究挑战了d频段中心理论在合金中的HER电催化学的广泛适用性.
- 当地电子环境和特定元素的吸附点对于理解HER在合金中的活性至关重要.
- 一个多维的火山情节的重新解释,考虑到超电位依赖机制和局部吸附能量,调和了合金电催化中的活性和粘合不一致性.
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