Zeolites as Selective Adsorbents for CO2 Separation

Zeolites are a very versatile class of materials that can display selective CO₂ adsorption behavior and thus find applications in carbon capture, storage, and utilization (CCSU). In this contribution, the properties of zeolites as CO₂ adsorbents are reviewed by critically presenting and discussing their assets and limitations. For this purpose, we first provide an overview of the CO₂ adsorption mechanisms on different types of zeolites. Then, we systematically discuss the relationship between the physicochemical properties of zeolites (framework type, Si/Al ratio, and extra-framework cations) and their performance as CO₂ adsorbents for the separation of CO₂/CH₄ (biogas) and CO₂/N₂ (flue gas) mixtures. Based on the trends and properties identified, we provide a comparison of the different zeolites and highlight their advantages and drawbacks for applicability in CO₂ adsorption. Finally, we present the state of the art in the shaping of zeolites in macroscopic format, which is a key step toward their industrial utilization as adsorbents.