Flexible nanoporous activated carbon cloth for achieving high H₂, CH₄, and CO₂ storage capacities and selective CO₂/CH₄ separation

Innovative tools are needed for the synthesis of smart, new, efficient, and safe nanoporous carbon materials for energy gas storage. Here, a flexible nanoporous activated carbon cloth was developed. Polypyrrole nanoparticles were polymerized in dispersed form on commercial viscose rayon cloth fiber surfaces. Then, the material was carbonized and activated by physical and chemical activation methods applied individually. Chemical activation conditions were varied and optimized. This produced a high porosity flexible nanoporous carbon textile with a surface area of ~2000 m² g⁻¹, total pore volume of 0.85 cm³ g⁻¹, and high nitrogen content. The new flexible nanoporous carbon cloth achieved superior H₂ and CH₄ storage capacities and CO₂ capture compared to so-far-reported activated carbon cloth, and values were comparable to or higher than those reported for powder activated carbons. Excess H₂ uptake values were 4.0 and 0.173 wt% at 77 K and 298 K at 20 bar, respectively, and CH₄ storage amounted to 7.5 mmol g⁻¹ at 20 bar and 298 K, which is among the highest reported values for porous carbon materials. CO₂ uptake values were 4.2 and 14.3 mmol g⁻¹ at 1 and 20 bar at 298 K, respectively, which are values superior to those previously reported for activated carbon cloth. Hence, the flexible nanoporous activated carbon cloth is effective for greenhouse gas (i.e., CO₂) uptake during post- and pre-combustion conditions. Separation selectivity for CO₂/CH₄ binary mixtures was evaluated based on the ideal adsorbed solution theory (IAST) model and a high value of 15.9 was achieved.