在半导体氧化物中单个原子位置的可见光光解
Michael G Allan1, Rachel A Yang1, Silvia Marino2
1Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.
Journal of the American Chemical Society
|December 27, 2024
概括
可见光激活氧化物中的催化剂以在温和的温度下去除一氧化碳 (CO). 这克服了紫外线激活的催化剂的局限性,使高效的CO光消耗和稳定的催化循环成为可能.
科学领域:
- 不同质的催化
- 材料科学
- 摄影化学
背景情况:
- 催化反应通常通过异质表面上的缩放关系而受到限制.
- 一氧化碳可以通过与 (Rh) 等金属形成稳定的复合物来毒害活性部位.
- 现有的从Rh位点的CO光衰减方法通常需要高能UV光子.
研究的目的:
- 设计具有可见光响应活性点的催化剂,以克服催化限制.
- 用可见光在温和条件下从明确的Rh位移除强结合的CO.
- 阐明不同催化系统中二氧化碳光消耗的不同机制.
主要方法:
- 将单个Rh位点纳入光活性氧化物 (Rh-doped SrTiO3).
- 在可见红光 (635 nm) 辐射下在323K处进行CO去除的研究.
- 进行严格的动力实验,以比较Rh-doped SrTiO3与支持的Rh/γ-Al2O3催化剂.
- 通过中间能量状态分析电子激发机制.
主要成果:
- 与支持的Rh催化剂不同的是,使用低能量的红光在温和的温度 (323K) 中从Rh辅助的SrTiO3中去除CO.
- 确定了不同的光消耗机制:Rh/γ-Al2O3的直接金属到配体电荷转移和Rh-doped SrTiO3的电子孔对形成.
- 可见光通过中间状态诱导Rh-doped SrTiO3中的电子激发,从而促进CO的去除.
- 在多次CO光消耗循环中, Rh-doped SrTiO3中的孤立Rh位点显示出极好的稳定性.
结论:
- 将单个Rh位点纳入光活性氧化物是可见光驱动表面化学的有效策略.
- 这种方法克服了依赖紫外线光解的局限性,并使温和温度的CO去除成为可能.
- 这些发现为设计超越化学反应缩放关系的先进催化剂提供了途径.
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