Mechanochemistry as a Reconstruction Tool of Decomposed Metal–Organic Frameworks

Abstract

Metal–organic frameworks (MOFs) undergo structural decomposition or phase transformation upon hydration in aqueous media or under harsh conditions, limiting their industrial commercialization. Herein, we present mechanochemical strategies to reconstruct four selected MOFs (MOF-5, MOF-177, UiO-67, and ZIF-65). To verify the effectiveness of this approach, these MOFs were intentionally decomposed in aqueous media and subsequently treated by ball milling under optimized conditions. As confirmed by X-ray diffraction analysis and N2 sorption isotherms, regardless of the MOF degradation pathway, the original structure could be recovered by a tailored mechanochemical reaction. This approach expands the practical applications of MOFs by enabling the regeneration of deteriorated MOFs quickly at a large scale.

Tethering Effects in Oligomer-Based Metal–Organic Frameworks

“…To probe the influence of oligomeric linkers on IRMOF-1 atmospheric moisture stability, a set of samples were activated from CH 2 Cl 2 at 25 °C, stored in ambient air, and characterized by PXRD to monitor changes in crystallinity. After 12 days of exposure to atmospheric moisture, IRMOF-1 shows complete loss of its original structure (Figure a) and converts to a structure with a PXRD pattern that matches Zn 2 (bdc)­(OH) 2 (CCDC reference code: PUCYAO01) . By contrast, oligoIRMOF-1 samples demonstrate notably different behavior when stored under these conditions.…”

“…After 12 days of exposure to atmospheric moisture, IRMOF-1 shows complete loss of its original structure (Figure 5a) and converts to a structure with a PXRD pattern that matches Zn 2 (bdc)(OH) 2 (CCDC reference code: PUCYAO01). 29 By contrast, oligoIRMOF-1 samples demonstrate notably different behavior when stored under these conditions. Use of the oligomeric linkers does not fully mitigate the high humidity degradation observed in the parent IRMOF-1 structure: 5 of the 8 oligomeric samples show complete loss of reflections associated with the MOF, yielding a diffraction pattern characterized by two broad peaks spanning 5−12 and 12− 30°2θ (Figure 5b).…”

Repetitive in situ recycling of degraded metal–organic frameworks within nanocapsules

“…Alternatively, mechanochemical synthesis has been utilized for the reconstruction of degraded MOFs back to their crystalline form. 25,26 Nonetheless, all current examples only demonstrated one degradation-reconstruction cycle. Repetitive recycling of any MOF, to the best of our knowledge, has yet to be realized.…”

The unique opportunities of mechanosynthesis in green and scalable fabrication of metal–organic frameworks

“…Lee et al also demonstrated the remarkable features of mechanosynthesis approaches for the reconstruction of a series of MOF materials including MOF-5, MOF-177, ZIF-65, and UiO-67. 246 N 2 sorption measurements and X-ray diffraction analysis were performed to evaluate the degree of MOF regeneration. The obtained results were highly acceptable which confirmed the high efficiency of mechanosynthesis approaches for the regeneration processes of degraded MOF materials also at large scales.…”