A scalable metal-organic framework as a durable physisorbent for carbon dioxide capture.

Metal-organic frameworks (MOFs) as solid sorbents for carbon dioxide (CO) capture face the challenge of merging efficient capture with economical regeneration in a durable, scalable material. Zinc-based Calgary Framework 20 (CALF-20) physisorbs CO with high capacity but is also selective over water. Competitive separations on structured CALF-20 show not just preferential CO physisorption below 40% relative humidity but also suppression of water sorption by CO, which was corroborated by computational modeling.

Achieving Superprotonic Conduction in Metal-Organic Frameworks through Iterative Design Advances.

Two complementary design strategies, isomorphous ligand replacement and heterocycle doping, have been applied to iteratively enhance the proton conductivity of a metal-organic framework, β-PCMOF2. The resulting materials, PCMOF2/(Pz) and PCMOF2/(Tz) (Pz = 1H-pyrazole, Tz = 1H-1,2,4-triazole), have their proton conduction raised almost 2 orders of magnitude compared to β-PCMOF2. The bulk conductivities of these materials are over 10 S cm at 85 °C and 90% relative humidity (RH), while maintaining the parent MOF structure.

A water-stable metal-organic framework with highly acidic pores for proton-conducting applications.

Metal-organic framework (MOF) materials are a nontraditional route to ion conductors, but their crystallinity can give insight into molecular-level transport mechanisms. However, some MOFs can be structurally compromised in humid environments. A new 3D metal-organic framework, PCMOF-5, is reported which conducts protons above 10(-3) S/cm at 60 °C and 98% relative humidity.

Enhancing proton conduction in a metal-organic framework by isomorphous ligand replacement.

Using the concept of isomorphous replacement applied to entire ligands, a C(3)-symmetric trisulfonate ligand was substituted with a C(3)-symmetric tris(hydrogen phosphonate) ligand in a proton conducting metal-organic framework (MOF). The resulting material, PCMOF2½, has its proton conduction raised 1.5 orders of magnitude compared to the parent material, to 2.

An amine-functionalized metal organic framework for preferential CO(2) adsorption at low pressures.

A metal organic framework with amine-lined pores gives high values for surface area and heat of adsorption with CO(2) gas.