Optimal Activation of Porous Carbon for High Performance CO₂ Capture

Abstract Various porous materials have shown a great promise as dry sorbents for carbon dioxide (CO₂) capture utilizing their large surface areas. Although there have been considerable efforts to find optimal pore size and geometry for a variety of porous materials, systematic experimental study covering various key parameters beside CO₂ uptake, such as isosteric heat and selectivity against other gas, is unavailable. Here, we systemically investigate the pore size effect on the CO₂ uptake and selectivity for porous activated carbon. We found that at each temperature and pressure, there exists an optimal intermediate activation condition that makes the pore size most appropriate for CO₂ uptake and selectivity. Further activation increases the pore size and weakens CO₂‐wall interaction. This study provides an important lesson that the pore activation of porous carbon should be controlled at an optimal intermediate point to maximize CO₂‐wall interaction.