单原子 Pt 位点的几何对称性破裂对于高效的电催化作用的重要性
Junsic Cho1, Taejung Lim2, Haesol Kim1
1Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
Nature communications
|June 3, 2023
概括
这项研究确定了低协调 (II) 种作为碳基单原子催化剂的关键活性位点. 这些发现澄清了位的难以捉摸的性质,并指导了未来的催化剂设计.
科学领域:
- 不同类型的电催化.
- 材料科学是一种材料科学.
- 表面化学 表面化学
背景情况:
- 单原子催化剂 (SAC) 对电催化有前景,但活 (Pt) 位点的精确性质仍然不太清楚.
- 实验观测和理论预测之间的差异引发了关于SAC中活跃Pt位点的身份的持续辩论.
- 了解Pt的协调和氧化状态对于优化催化剂性能至关重要.
研究的目的:
- 确定基于碳的SAC中的活性位的特定化学性质和协调.
- 研究不同种在演化反应 (CER) 中的作用.
- 为设计基于d8金属离子的高性能SAC提供准则.
主要方法:
- 使用先进的现场光谱技术来探测Pt SACs的电子和结构性质.
- 合成的基于碳的SACs具有不同的Pt负载,低至0.15 wt.%,以区分活性站点.
- 研究了这些SACs在演化反应中的催化活性.
主要成果:
- 在基于碳的SAC上确定了低协调 (PtII) 种类的稳定.
- 除了通常提出的四个协调的PtII-N4站点之外,还揭示了多个PtII部分.
- 证明了低协调的PtII物种对于高效的演化反应至关重要,特别是在低Pt负载下.
结论:
- 低协调的PtII物种,很少被观察到在同质催化中作为中间体,是异质Pt SAC中至关重要的活性位点.
- 该研究阐明了PtII在碳支上的复杂物种化,超越了理想化的模型.
- 这些发现为优化SAC提供了总体策略,通过针对其他d8过渡金属的特定低协调金属物种来优化SAC.
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