Exploring Kinetic and Thermodynamic Insights of Graphene Related Two Dimensional Materials for Carbon Dioxide Adsorption

Graphene related two dimensional materials (GR2Ms) are promising adsorbents for CO 2 capture. However, the CO 2 adsorption kinetics and mechanisms on these materials remain insufficiently explored and understudied. Recognizing the pivotal role of adsorption kinetics in assessing the practical applicability, this study comprehensively evaluates the CO 2 adsorption kinetics, underlying mechanisms, and thermodynamic properties via gravimetric analysis on three distinct well -characterized graphene materials (few layer graphene-FLG, graphene oxide -GO, reduced graphene oxide-rGO) across temperatures from 25 to 75 degrees C under atmospheric pressure. Results reveal that Avrami ' s fractional model offers the most accurate fit for CO 2 adsorption kinetics among the three examined models (pseudo -first, pseudo -second, and Avrami ' s fractional order). The interplay between the physico-structural-chemical properties of GR2Ms and the CO 2 adsorption kinetics discloses that the morphology, crystallite size, specific surface area and porosity of GR2Ms greatly influence the CO 2 adsorption rate as evidenced by the largest rate constant, k A value of rGO at 25 to 75 degrees C under atmospheric pressure. Analysis of activation parameters including activation energy, enthalpy of activation, entropy of activation, and free energy of activation derived from Eyring, Arrhenius, and Gibbs equations indicates a greater favorability of CO 2 adsorption on GR2Ms at lower temperatures. Moreover, investigation into the underlying interaction mechanisms between CO 2 molecules and GR2Ms, using rate -limiting kinetic models (Boyd ' s film diffusion model, interparticle diffusion model, and intraparticle diffusion model), confirms that both film diffusion resistance and intraparticle diffusion resistance predominantly govern the CO 2 adsorption rate.