A versatile synthesis of metal-organic framework-derived porous carbons for CO₂ capture and gas separation

We report a versatile fabrication method, detailed material characterization, pore architecture formation patterns, and surface functionality of MIL-100Al-derived porous carbons. Oxygen-doped porous carbons were prepared via carbonization of MIL-100Al, MIL-100Al/F127 composite, and MIL-100Al/KOH mixture. Microscopy tools showed different Al₂O₃ composite patterns and morphologies in the carbon particles, and a coherent discussion of versatile fabrication methods on carbon textural properties is demonstrated. The obtained porous carbons have a large specific surface area (up to 1097 m² g⁻¹), well-developed narrow microporosity (up to 92% of the pore volume arises from micropores), and excellent CO₂ adsorption capacities of 6.5 mmol g⁻¹ at 273 K and 4.8 mmol g⁻¹ at 298 K at an ambient pressure, which is among the highest reported so far for the MOF-derived carbons. Furthermore, excellent CO₂/N₂ selectivity of 45, CO₂/CH₄ selectivity of 14.5, and CH₄/N₂ selectivity of 5.1 were achieved at 298 K and 1 bar. Kinetic selectivity was also calculated, in which high CH₄/N₂ selectivity (up to 11) was reached at 273 K and 1 bar. Potent gas separation performance and outstanding regenerability, demonstrated by breakthrough simulation and adsorption–desorption cycling tests, enable these MOF derived porous carbons to function as suitable solid adsorbents for CO₂ capture from flue gas and bio-gas upgradation.