Carbon Capture: Theoretical Guidelines for Activated Carbon-Based CO₂ Adsorption Material Evaluation

Activated carbon (AC)-based materials have shown promising performance in carbon capture, offering low cost and sustainable sourcing from abundant natural resources. Despite ACs growing as a new class of materials, theoretical guidelines for evaluating their viability in carbon capture are a crucial research gap. We address this gap by developing a hierarchical guideline, based on fundamental gas-solid interaction strength, that underpins the success and scalability of AC-based materials. The most critical performance indicator is the CO₂ adsorption energy, where an optimal range (-0.41 eV) ensures efficiency between adsorption and desorption. Additionally, we consider thermal stability and defect sensitivity to ensure consistent performance under varying conditions. Further, selectivity and capacity play significant roles due to external variables such as partial pressure of CO₂ and other ambient air gases (N₂, H₂O, O₂), bridging the gap between theory and reality. We provide actionable examples by narrowing our options to methylamine- and pyridine-grafted graphene.