Capture, Storage, and Release of Oxygen by Metal–Organic Frameworks (MOFs)

Abstract

Oxygen is a critical gas for medical and industrial settings. Much of today's global oxygen supply is via inefficient technologies such as cryogenic distillation, membranes or zeolites. Metal–organic frameworks (MOFs) promise a superior alternative for oxygen separation, as their fundamental chemistry can in principle be tailored for reversible and selective oxygen capture. We evaluate the characteristics for reversible and selective uptake of oxygen by MOFs, focussing on redox‐active sites. Key characteristics for separation can also be seen in MOFs for oxygen storage roles. Engineering solutions to release adsorbed oxygen from the MOFs are discussed including Temperature Swing Adsorption (TSA), Pressure Swing Adsorption (PSA) and the highly efficient Magnetic Induction Swing Adsorption (MISA). We conclude with the applications and outlooks for oxygen capture, storage and release, and the likely impacts the next generation of MOFs will have on industry and the broader community.

Noncryogenic Air Separation Using Aluminum Formate Al(HCOO)3 (ALF)

“…To the best of our knowledge, ALF has the highest O 2 /N 2 sorption selectivity verified by co-adsorption experiments among MOF adsorbents without open metal sites. 9 With its great application potential for noncryogenic air separation demonstrated, ALF also has a significant advantage compared with all other MOFs in terms of its ease of synthesis, low cost, and scalability.…”

Two-dimensional Cd3-based metal–organic frameworks with halogen bonding sites for the uptake of I2

“…8 High-dimensional porous materials, such as metal–organic frameworks (MOFs) and covalent–organic frameworks (COFs) have also appeared as an emerging class of adsorbents for iodine capture, 9 with advantages including versatility in structure, high surface areas, designable and tunable pore features, high thermal/chemical stabilities, and potential for post-synthetic modification. 10 Zeolitic imidazolate framework 8 (ZIF-8), for example, exhibits an exceptional uptake of I 2 because of an ideal pore aperture size of 3.4 Å which matches the ca. 3.35 Å diameter of I 2 , permitting directional diffusion into the pore.…”

ZIF-8-Supported AgInS2 Quantum Dots for Photocatalytic H2 Production by Precise Location Sulfurization

“…MOFs are a class of crystalline porous materials with periodic network structure formed by the self-assembly of inorganic metal centers (metal ions or metal clusters) and bridged organic ligands. MOFs have many applications for chemical fields because of their excellent properties like porosity, large specific surface area, and multimetallic sites, such as gas storage, molecular separation, catalysis, drug-sustained release, etc. − However, most of the MOFs show low photocatalytic activity because of their wide energy gap and too-rapid recombination of photogenerated carriers . It is an ideal approach to improve the photocatalytic activity of MOFs combined with semiconductor QDs.…”