The regulation of metal cations in zeolites via ion exchange to enhance CO₂ adsorption performance holds significant potential for the efficient industrial capture of CO₂. To investigate the correlation between metal cation exchange time and CO₂ adsorption performance of zeolites, four adsorbent samples (e.g. Ca?LTA?30) were prepared with exchange time as the independent variable. The textural properties, thermal stability, CO₂ temperature?programmed desorption (CO₂?TPD), and CO₂ adsorption performance of these samples were characterized. Furthermore, the IAST (Ideal Adsorbed Solution Theory) selectivity of these samples for CO₂/N₂ gas mixtures with different volume ratios (20∶80, 50∶50, 80∶20) was compared. The results indicate that the CO₂ adsorption performance of LTA can be increased from 5.02 mmol/g to 6.05 mmol/g, while the S_CO {}_{{}_{}^{}} _/N {}_{{}_{}^{}} can be improved from 59.7 to 118.5. In addition, through comparing the fitting performance of four adsorption models on the adsorption isotherms of CO₂ and N₂ on LTA and Ca?LTA series samples, it is found that the Langmuir?Freundlich model exhibits the best consistency with the experimental data and can effectively evaluate the CO₂ adsorption behavior of the Ca?LTA series samples.

In this paper, the method of combining Grand Canonical Monte Carlo simulation and Ideal Adsorption Solution Theory was used to study the adsorption performance of CO₂ and CH₄ on NaX zeolite. By comparing the fitting results of simulation data under different adsorption theoretical models and calculating the adsorption heat, a description of the adsorption and separation process of CO₂ and CH₄ gas was obtained. The results show that the adsorption strength of CH₄ molecules is weaker than that of CO₂ molecules, and its adsorption is closer to the ideal adsorption. The adsorption selectivity of CO₂ molecules is decreases with the increase of its content in the air, and decreases with the increase of temperature under low pressure conditions. Therefore, low temperature and low pressure are more conducive to the separation of CO₂ molecules.