Adsorptive-dissolution of O2 into the potential nanospace of a densely fluorinated metal-organic framework

Summary

The study reports a densely fluorinated metal-organic framework (PFAC-2) that exhibits "adsorptive-dissolution" behavior, capturing oxygen molecules without changing its framework structure, and selectively adsorbing O2 over Ar.

Highlights

• PFAC-2 exhibits "adsorptive-dissolution" behavior, capturing oxygen molecules without changing its framework structure.
• The MOF has a densely fluorinated nanospace that selectively adsorbs O2 over Ar.
• The adsorption isotherm of O2 shows a steep increase at 0.12P/P0 due to gate-opening adsorption.
• In situ PXRD measurements reveal that the MOF structure changes during gate-opening adsorption.
• The MOF has a high O2/Ar selectivity, making it suitable for gas separation applications.
• Theoretical calculations suggest that the fluorinated nanospace plays a crucial role in the selective adsorption of O2.
• The MOF's structure and adsorption properties are maintained after repeated adsorption and desorption cycles.

Key Insights

• The "adsorptive-dissolution" behavior of PFAC-2 is attributed to the densely fluorinated nanospace, which allows for the reorganization of fluoroalkyl chains to accommodate gas molecules.
• The selective adsorption of O2 over Ar is due to the stronger interaction between O2 and the fluorinated nanospace, as revealed by theoretical calculations.
• The gate-opening adsorption behavior of PFAC-2 is triggered by the reorganization of fluoroalkyl chains, which creates a pathway for gas molecules to enter the MOF.
• The high O2/Ar selectivity of PFAC-2 makes it a promising material for gas separation applications, particularly in the context of oxygen production.
• The stability and recyclability of PFAC-2 are crucial for its practical application, and the study demonstrates that the MOF's structure and adsorption properties are maintained after repeated adsorption and desorption cycles.
• The study highlights the importance of designing MOFs with tailored properties for specific applications, and the potential of fluorinated MOFs for gas separation and storage.
• The "adsorptive-dissolution" behavior of PFAC-2 challenges the traditional understanding of adsorption and dissolution, and opens up new avenues for the design of materials with unique properties.

Mindmap

Citation

Kusaka, S., Itoh, Y., Hori, A., Usuba, J., Pirillo, J., Hijikata, Y., Ma, Y., & Matsuda, R. (2024). Adsorptive-dissolution of O2 into the potential nanospace of a densely fluorinated metal-organic framework. In Nature Communications (Vol. 15, Issue 1). Springer Science and Business Media LLC. https://doi.org/10.1038/s41467-024-54391-y