调节器控制混合金属UiO-66 ((Zr,Ce) 金属有机框架中的电离子分布
Baiwen Zhao1, Martin Hutereau2, Marc Walker3
1Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, U.K.
Chemistry of materials : a publication of the American Chemical Society
|December 31, 2025
概括
像酸这样的调节剂控制双金属UiO-66-(Ce/Zr) 金属有机框架 (MOF) 中的金属分布,增强合并和氧化反应中的催化活性.
科学领域:
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
- 纳米技术纳米技术
背景情况:
- 像UiO-66-(Ce/Zr) 这样的双金属金属有机框架 (MOF) 对催化有希望.
- 控制MOF集群内的阴离子分布对于调性质至关重要.
- 合成过程,特别是调节器的选择,影响MOF结构和性能.
研究的目的:
- 研究不同调节剂如何影响UiO-66-(Ce/Zr) MOF中的阴离子分布和氧化还原活性.
- 为了将Ce-Zr集群的局部结构与醇氧化中的催化性能相关联.
- 了解MOF合成期间合物的机制.
主要方法:
- 扩展的X射线吸收光谱 (EXAFS) 在Ce和ZrK边缘.
- 在现场的里埃变换红外光谱 (FTIR).
- 密度函数理论 (DFT) 的计算.
- Ce K边缘EXAFS和Ce LIII边缘X射线吸收近边缘结构 (XANES) 分析反应溶液.
- 微波辅助醇氧化反应.
主要成果:
- 酸调制有利于形成Cis-Ce2Zr4集群,与酸 (17%的CeZr5集群) 相比,Ce结合率更高 (33%).
- 溶液中的Ce (III) 限制了Ce (IV) 的吸收,但酸减轻了这种影响,增强了整体Ce的纳入.
- cis-Ce2Zr4集群在醇氧化中表现出比CeZr5集群更高的氧化还原活性和催化效率.
- 当地金属分布显著影响催化活性,cis-Ce2Zr4集群由于更容易去除氧化物离子而表现出优越的性能.
结论:
- 调节器的选择是控制UiO-66-(Ce/Zr) MOF集群内的局部阴离子分布的一个关键因素.
- 通过调节器选择微调金属集群结构,提供了一种微妙但有效的策略来增强催化性能.
- 了解和控制阴离子分布对于设计针对特定应用的先进MOF催化剂至关重要.
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