Leveraging porosity and morphology in hierarchically porous carbon microtubes for CO2 capture and separation from humid flue gases

Leveraging porosity, surface chemistry and morphology of porous carbons plays a critical role in CO 2 capture performance. However, the effective and sustainable synthesis of porous carbons with well-interconnected hierarchical pore structure, high-proportioned micropores and high yield remains a huge challenging by a mild one-step chemical activation without damaging the natural unique nanostructure. Here, we proposed a green and sustainable strategy to fabricate porous carbons with tailorable porosity and unique tubular structure by an inorganic dynamic porogen of CuCl 2 . The dynamic activation mechanism of CuCl 2 was explored in detail. In particular, the hierarchical porosity with a high-proportioned narrow micropores can be finely tuned without sacrificing the natural tubular morphology. Importantly, the resultant porous carbon adsorbents have an excellent resistance to water vapor, which can capture CO 2 from humid flue gases with satisfactory adsorption capacity and selectivity. The HPCM-3 can achieve the best CO 2 uptakes of 4.05 and 2.05 mmol/g under 100 kPa at 25 and 50 °C, respectively. Such superior CO 2 adsorption behaviors can be well maintained even at high humidity of 70 %, and hardly decay with the enhancement of humidity. This route provides a promising avenue for developing the practical trace CO 2 carbon-based adsorbents on a large scale to sieve CO 2 from humid flue gases.