We designed and synthesized a perfluorinated covalent triazine-based framework (FCTF-1) for selective CO₂ capture. The incorporation of fluorine (F) groups played multiple roles in improving the framework's CO₂ adsorption and separation capabilities. Thermodynamically, the strongly polar C–F bonds promoted CO₂ adsorption via electrostatic interactions, especially at low pressures. FCTF-1's CO₂ uptake was 1.76 mmol g⁻¹ at 273 K and 0.1 bar through equilibrium adsorption, exceeding the CO₂ adsorption capacity of any reported porous organic polymers to date. In addition, incorporating F groups produced a significant amount of ultra-micropores (<0.5 nm), which offered not only high gas adsorption potential but also kinetic selectivity for CO₂–N₂ separation. In mixed-gas breakthrough experiments, FCTF-1 exhibited an exceptional CO₂–N₂ selectivity of 77 under kinetic flow conditions, much higher than the selectivity (31) predicted from single-gas equilibrium adsorption data. Moreover, FCTF-1 proved to be tolerant to water and its CO₂ capture performance remained excellent when there was moisture in the gas mixture, due to the hydrophobic nature of the C–F bonds. In addition, the moderate adsorbate–adsorbent interaction allowed it to be fully regenerated by pressure swing adsorption processes. These attributes make FCTF-1 a promising sorbent for CO₂ capture from flue gas.

The removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene is a technologically very important, but highly challenging task. Current removal approaches include the partial hydrogenation over a noble metal catalyst and the solvent extraction of cracked olefins, both of which are cost and energy consumptive. Here we report a microporous metal–organic framework in which the suitable pore/cage spaces preferentially take up much more acetylene than ethylene while the functional amine groups on the pore/cage surfaces further enforce their interactions with acetylene molecules, leading to its superior performance for this separation. The single X-ray diffraction studies, temperature dependent gas sorption isotherms, simulated and experimental column breakthrough curves and molecular simulation studies collaboratively support the claim, underlying the potential of this material for the industrial usage of the removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene at room temperature through the cost- and energy-efficient adsorption separation process.

Nitrogen-doped carbon materials were prepared by a nanocasting route using tri-continuous mesoporous silica IBN-9 as a hard template. Rationally choosing carbon precursors and carefully controlling activation conditions result in an optimized material denoted as IBN9-NC1-A, which possesses a very high nitrogen doping concentration (∼13 wt%) and a large surface area of 890 m² g⁻¹ arising from micropores (<1 nm). It exhibits an excellent performance for CO₂ adsorption over a wide range of CO₂ pressures. Specifically, its equilibrium CO₂ adsorption capacity at 25 °C reaches up to 4.50 mmol g⁻¹ at 1 bar and 10.53 mmol g⁻¹ at 8 bar. In particular, it shows a much higher CO₂ uptake at low pressure (e.g. 1.75 mmol g⁻¹ at 25 °C and 0.2 bar) than any reported carbon-based materials, owing to its unprecedented nitrogen doping level. The high nitrogen contents also give rise to significantly enhanced CO₂/N₂ selectivities (up to 42), which combined with the high adsorption capacities, make these new carbon materials promising sorbents for selective CO₂ capture from power plant flue gas and other relevant applications.