Zeolites for CO₂ capture - An overview

The rising atmospheric concentration of carbon dioxide (CO₂) has prompted extensive research into effective capture technologies. Among a variety of sorbents, zeolites have emerged as promising solid adsorbents, offering uniquely tunable properties dictated by their framework structures, channel dimensions, Si/Al ratio, high surface area, cation type, and selective adsorption properties. This overview focuses on the application of zeolites for CO₂ capture with particular emphasis on direct air capture (DAC) and post-combustion scenarios. The structural features and performance characteristics of various zeolite frameworks, including A, ZSM-5, X, Y, β, SAPO, and RHO have been detailed. The discussion highlights that CO₂ affinity is primarily controlled by cation exchange for electrostatic tuning and pore size for molecular sieving effects. Recent advances in surface modifications (e.g., amine functionalization) and the integration of hybrid materials are summarized, specifically evaluating improvements in CO₂ uptake and selectivity from mixed gases. By compiling and comparing results from recent studies, this paper highlights how synthesis methods, particle morphology, and testing conditions impact adsorption performance. Ultimately, zeolites show significant potential; however, further research is required to enhance the stability and capacity of these adsorbents for efficient real-world carbon capture applications.