A dispersion-corrected DFT method for zeolite-based CO2/N2 separation: Assessment and application

In occupational risk prevention, it has become a priority to capture gaseous species in exhaust fumes from anthropogenic sources such as diesel/gasoline engines, coal power plants, post-combustion, biogas production from waste. Solid-phase gas adsorption is widely used in industrial and domestic applications. Its efficiency is closely linked to the properties of the material chosen. The aim of this study was to validate a methodology based on periodic dispersion-corrected Density Functional Theory (DFT) to screen solid-phase materials to determine their gas adsorption efficiency. DFT can be used to study the efficiency and selectivity of adsorbents according to several models. Our methodology was assessed using the well-known chemical model of CO2/N2 adsorption onto various cation-exchanged faujasite zeolites. All cationic sites of the faujasite supercage were considered for gas adsorption when calculating the adsorption enthalpy. DFT results were validated using experimental adsorption isotherms obtained by two approaches, the Langmuir, Dubinin-Radushkevich and isostere methods. Results showed close correlation between experimental and modeling results, indicating that our DFT method has potential to classify solid-phase gas adsorbents for use in occupational risk prevention.