Highly Efficient CO₂ Capture from Wet-Hot Flue Gas by a Robust Trap-and-Flow Crystal

Highly selective CO₂ capture from flue gas based on adsorption technology is among the largest challenge on the horizon, due to its high temperature (>333 K), lower partial pressure (0.1-0.2 bar), and competition from water. Due to the designable and tunable pore system, porous coordination polymers (PCPs) have been considered as the most exciting discoveries in porous materials. However, the rational design and function-led preparation of the pore system that permits highly selective CO₂ capture from flue gas (CO₂/N₂/O₂/CO/H₂O) remains a great challenge. Herein, we report a highly selective CO₂ capture from wet-hot (363 K, RH = 40%) flue gas by a robust trap-and-flow crystal (NTU-67). Crystallographic analysis showed that the flow channel provides plausible CO₂ traffic, while the confined trap works as an accommodation for captured gas molecules. Further, the hydrophobic pore surface endows the function of the channels that are not influenced by hot moisture, a major obstacle to overcome direct CO₂ capture by PCPs. The integral nature of NTU-67, including good stability in SO₂, meets the key prerequisites that are usually considered for practical applications. The molecular insight and highly efficient CO₂ capture make us believe that different nanospace with their own duties may be extended into ingenious design of more advanced adsorbents for cost-effective and promising for CO₂ capture from flue gas.