在金属二聚酸框架家族中的可逆CO2 - CO3转化
Xiang-Jing Kong1,2, Tao He1,2, Andrey A Bezrukov2
1Beijing Key Laboratory for Green Catalysis and Separation and Department of Chemical Engineering, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, PR China.
Journal of the American Chemical Society
|October 8, 2024
概括
研究人员开发了新的-酸盐框架 (fcu-L-Co),可以在多孔晶体结构中可逆地在氧化状态 (Co(II) 到Co(III) 之间切换. 这一突破使得空气中的氧化还原活性保持结晶性,这是金属有机框架 (MOF) 罕见的功绩.
科学领域:
- 协调化学
- 材料科学
- 晶体学
- 纳米技术
背景情况:
- 氧化状态转化在过渡金属化学中很常见,但在稳定,多孔的晶体固体中很少见.
- 现有的金属有机框架 (MOF) 往往缺乏在空气中进行这种转换的结构稳定性或固有氧化还原活性.
- 在稳定,多孔的晶体结构中表现出受控的氧化还原化学物质的开发是一个重大挑战.
研究的目的:
- 报告一个面中心立方 (fcu) 拓的新一代酸盐框架 (fcu-L-Co).
- 在这些MOF中,在Co (II) 和Co (III) 状态之间进行自发和可逆的空气诱导氧化,保持结晶性.
- 研究这种氧化还原转换对材料的特性,如水蒸气吸收和框架稳定性的影响.
主要方法:
- 使用Co8分子构建块和二甲酸连接物合成四种同结构-酸框架 (fcu-L-Co).
- 将fcu-L-Co暴露在空气中以诱导CO2到CO3的氧化,并用水性酸盐处理反向反应.
- 使用单晶X射线衍射和现场光谱来理解转换机制的表征.
- 在不同相对湿度下测量两种氧化状态的水蒸气吸附特性.
主要成果:
- 一个具有fcu拓的新型酸框架 (fcu-L-Co) 已成功合成.
- 这些MOF在暴露在空气中时自发转化为CO2到CO3,并保持结晶性.
- 使用水性水实现了反向转化 (Co(III) 到Co(II)).
- fcu-L-Co ((II) 显示出高水蒸气吸收率 (0.55-0.68 g g-1 在30% RH),而fcu-L-Co ((III) 显示出更好的框架稳定性和转移的水吸附拐点.
- 单晶X射线衍射和现场光谱学提供了对Co (II) /Co (III) 转换的见解.
结论:
- 晶体工程方法产生了一种新型的MOF,能够在狭窄,多孔的环境中进行氧化还原化学.
- 这些材料显示出罕见的气体诱导氧化现象,在MOF中保留了结晶性.
- 可逆氧化还原活性和可调节性质使fcu-L-Co框架在需要氧化还原活性多孔材料的应用中具有前景.
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