Revealing the structure–property relationship of all-silica zeolites for the carbon dioxide capture: a high throughput screening study

Abstract

The structural parameters and performance evaluation metrics of 242 promising all-silica zeolites to rank and screen out the top candidates for CO2/N2 separation are obtained by using molecular simulations combined with high-throughput calculations. By setting the pore size range of the material, three top zeolites with the highest adsorption selectivity for CO2 molecules are screened to further investigate the adsorption and separation for CO2 and N2 molecules. The GCMC method was used to calculate the adsorption isotherm, heat of adsorption, adsorption selectivity and centroid distribution density under different feed ratios of CO2/N2 mixed components. The zeolite exhibits a high CO2 adsorption capacity with the maximum pore size of 4–8 Å, the surface area of 1400 m2/g and the pore volume of 0.2–0.4 cm3/g, and best adsorption selectivity for CO2 at the pore size of 4 Å and pore volume of 0.2 cm3/g in the CO2/N2 mixed systems. Zeolite has higher adsorption selectivity for CO2 with low amount of CO2, which is favorable for the removal of a small amount of CO2 molecules. The geometrical structure of the material plays an important role for the adsorption capacity and spatial distribution of the adsorbate molecules in all-silicon zeolites.