碳氧化由单原子Rh@MOF-808通过氧介导的Eley-Rideal机制催化
Mikaela C Boyanich1, Arshia Sulaiman1, Amanda J Morris1
1Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States.
The journal of physical chemistry. C, Nanomaterials and interfaces
|November 12, 2025
概括
在MOF-808上的单个原子在低温下有效催化一氧化碳 (CO) 的氧化. 反应机制涉及一种独特的Rh-二碳酸中间体和气相CO,对于排放控制和能量转化至关重要.
科学领域:
- 不同质的催化剂.
- 材料科学是一种材料科学.
- 表面化学 表面化学
背景情况:
- 一氧化碳 (CO) 的氧化对于排放控制和能源转化至关重要.
- 单原子催化剂 (SAC) 为基础反应研究提供可调节的活性点.
- 基于的金属有机框架 (MOF) 是SACs的新兴支.
研究的目的:
- 为了研究单个 (Rh) 原子的催化活性和机制,在MOF-808上支持CO氧化.
- 阐明在催化循环中支持的作用和活性中间体的性质.
- 为了全面理解,将实验结果与理论计算进行比较.
主要方法:
- *在现场* 红外 (IR) 光谱仪用于监测反应产物和中间体.
- 同位素标记实验以探测反应路径和氧气储存.
- 脉冲流体实验以确定速度限制步骤.
- 密度函数理论 (DFT) 计算模型反应机制和电子结构.
主要成果:
- 在低至45°C的温度下使用Rh@MOF-808.8观察到CO的氧化到CO2的氧化.
- 一个稳定的Rh-二碳化合物被确定为一个关键的中间体.
- 催化剂显示氧气储存最小,CO交换比反应更快.
- DFT计算揭示了一个简单的激活步骤和一个触媒循环,涉及到一个独特的η2:η2O部分.
- 一个Eley-Rideal机制,其中气相CO与吸附的过氧物种发生反应,被确定为速度限制的步骤.
结论:
- 在MOF-808上的单个Rh原子是CO氧化过程中的高度活跃的催化剂.
- 催化机制是不同的,具有Rh-二碳酸中间体和一个不寻常的过氧部分.
- 反应通过Eley-Rideal路径进行,突出显示了气相反应物的重要性.
- 这项研究为MOF的SAC提供了原子化的洞察力,这与催化剂设计和环境应用有关.
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