吸附剂交换诱导的MOF中的相变
Alexander V Neimark1, Nicholas J Corrente1, François-Xavier Coudert2
1Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854, United States.
Langmuir : the ACS journal of surfaces and colloids
|February 17, 2025
概括
灵活的金属有机框架 (MOF) 在气体吸附时表现出呼吸阶段过渡. 一个新的理论框架解释了二氧化碳如何在MIL-53 MOF中取代甲,触发这些转换.
科学领域:
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
- 纳米技术 纳米技术
背景情况:
- 气体吸附会诱导纳米孔材料的变形,这对于气体储存和分离等应用至关重要.
- 金属有机框架 (MOF) 呈现"呼吸"阶段转换,涉及客分子吸附/脱附的显著体积变化.
研究的目的:
- 开发一个理论框架,以量化描述MOF在二元气体混合物吸附过程中的呼吸过渡.
- 阐明MIL-53 MOF中框架变形和相位转换 (大孔向窄孔) 的机制.
主要方法:
- 开发了一个基于吸附应力概念的理论框架.
- 应用框架来建模MIL-53 MOF中二氧化碳 (CO2) 对甲 (CH4) 的取代.
- 将理论预测与吸附和应变异热体的实验数据进行比较.
主要成果:
- 在甲吸附过程中,微小的二氧化碳添加会使MIL-53 MOF的大孔 (LP) 阶段不稳定,从而触发过渡到狭孔 (NP) 阶段.
- 反向的狭孔向大孔 (NP-LP) 转换发生在甲进一步被二氧化碳所取代时.
- 吸附和应变等温的理论预测与MIL-53的实验研究非常一致.
结论:
- 提出的理论方法准确地描述了MOF中由二元气体混合物诱导的呼吸阶段过渡.
- 该研究揭示了由选择性气体吸附驱动的框架变形的潜在机制.
- 一般框架适用于其他灵活的纳米多孔材料和气体混合物.
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