Structural Insight of MOFs under Combined Mechanical and Adsorption Stimuli. (24th March 2022)

• Record Type: Journal Article
• Authors: Iacomi, Paul; Alabarse, Frederico; Appleyard, Roger; Lemaire, Thomas; Thessieu, Christophe; Wang, Sujing; Serre, Christian; Maurin, Guillaume; Yot, Pascal G.
• Is Part Of: Angewandte Chemie. Volume 134:Number 22(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-24
• Subjects: Combined Mechanical Stress/Gas Pressure Stimuli -- Flexible MOFs -- In Situ Structural Characterisation; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202201924
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: External control over the pore size of flexible metal–organic frameworks (MOFs) has recently emerged as an intriguing concept, with possible applications to gas storage and separation. In this work we present a new pressure cell capable for the first time of monitoring through in situ X‐ray powder diffraction an adsorbent powder under combined uniaxial applied mechanical stress (up to 1 GPa) and gas pressure (up to 20 bar). The combined stress–pressure clamp (CSPC) cell was successfully exploited to follow the evolution of the CO2 breathing behaviour of the prototypical complex breathing MIL‐53(Al) system under mechanical compression obtaining structural evidence that this MOF can be maintained in its closed pore state upon compression, precluding its re‐opening at high gas pressure (>7 bar). This novel setup shows potential for the in‐ operando exploration of flexible systems, in equilibrium and flow configurations. Abstract : A new in situ pressure cell was designed that can follow materials under two combined stimuli: gas pressure and mechanical stress, providing structural insight into phase transformations of stimuli‐responsive materials. The cell was used to gain direct evidence that mechanical stress can control MIL‐53(Al) breathing behaviour with CO2, further paving the way for dynamic tuning of separation performance for compliant MOFs.