The edge-functionalization enhances the competitive adsorption of CO₂over CH₄in NPCs by improving pore topology, electronegativity, adsorption energy, and electrostatic contribution.

Strategies to enhance CO ₂ capture and separation based on state-of-the-art adsorbent materials have been proposed by topological structure design, chemical doping, chemical functionalization, open metal sites, and electric fields. This review presents a constructive way for the design and screening of novel adsorbent materials.

A porous Cu metal–organic framework (1) based on a pentacarboxylate ligand and paddlewheel SBU was synthesized and structurally characterized. Complex 1 possesses a NbO-type framework with uncoordinated –COO⁻ groups, resulting in its good selectivity for CO₂/N₂ (36) and CO₂/CH₄ (12) as well as a large CO₂-uptake capacity of 140 cm³ g⁻¹ at 273 K and 1 bar. Grand Canonical Monte Carlo (GCMC) simulations revealed that strong CO₂ adsorption sites exist near the open Cu^II sites and the uncoordinated –COO⁻ groups. Significantly, complex 1 exhibits water resistance and selective adsorption of cationic methylene blue (MB⁺) in aqueous solution and the adsorbed MB⁺ can be released in saturated NaCl solution, making it also a promising porous material for charge and pore-size dependent large-molecule capture and separation. The existence of coordinatively unsaturated metal sites as well as the exposed –COO⁻ groups in the framework of 1 is responsible for its selective gas adsorption and dye separation.

The storage and separation of hydrocarbons is of great importance for the petrochemical industry. Herein, we report a fluorine-functionalized microporous indium (In) metal–organic framework (UPC-104) for light hydrocarbon storage and separation. UPC-104 can be stable up to 300 °C, and can retain its framework in acidic and alkaline aqueous solutions (pH 1–11). Remarkably, the material exhibits very high H₂ (230.8 cm³ g⁻¹, 2.06 wt% at 77 K and 1 bar), C₂H₂ (187.0 cm³ g⁻¹ at 273 K and 1 bar), and C₃H₆/C₃H₈ adsorption capacity (276.5 cm³ g⁻¹ and 250.4 cm³ g⁻¹ for C₃H₆ and C₃H₈ at 273 K and 1 bar), and shows potential for the separation of light hydrocarbons (C₂H₂, C₂H₄, C₂H₆, C₃H₆, C₃H₈, n-C₄H₁₀, and i-C₄H₁₀ relative to CH₄), as shown by single component gas sorption and selectivity calculations.