From Molecular Simulation to Equation of State: CO2 Adsorption Enthalpies on CAU-10-H and CALF-20

Carbon capture from industrial sources is a key strategy for mitigating carbon dioxide (CO₂) emissions. CAU-10-H and CALF-20 are metal–organic frameworks that exhibit favorable properties for post-combustion CO₂ capture, combining adsorption-site heterogeneity and robust physisorptive behavior. The molar adsorption enthalpy (Δ_adsℎ) is evaluated using two complementary approaches: Grand-Canonical Monte Carlo (GCMC) simulations and a molecular-based equation of state (EoS) derived from SAFT-VR Mie. In GCMC, Δ_adsℎ is obtained from energy–particle fluctuations using a rigid framework description, while the EoS enables its calculation from Helmholtz free energy relations. Results are benchmarked against experimental Clausius–Clapeyron enthalpies, ensuring thermodynamic consistency across methods.