Preparation and characterization of pitch-based nanoporous carbons for improving CO₂ capture

Pitch is considered a promising low-cost carbon precursor. However, when pitch is pyrolyzed, it forms polycrystalline graphite, which is non-porous, and therefore, not useful for CO₂ adsorption. In this work, pitch was chemically activated to obtain a large specific surface area and micropore volume. Varying weight ratios of KOH (i.e., 0, 1, 2, and 3) were used as the activating agent. The characteristics of the samples were investigated using scanning electron microscopy (SEM), N₂/77 K adsorption isotherms, and X-ray diffraction (XRD). The CO₂ adsorption performance was studied by isothermal adsorption/desorption measurements. The results showed that an increase in specific surface areas and total pore volumes of pitch-based nanoporous carbons, resulted in an enhancement of CO₂ adsorption capacity.