Small Gas Adsorption and Separation in Small-Pore Zeolites

Abstract

The capture, storage, and utilization of small gases by economically viable recyclable microporous adsorbents is an ever-expanding field of research toward industrially relevant separations, as well as toward pollution remediation and catalysis. The use of thermochemically stable zeolitic adsorbents has the potential to fill these markets, as they are already widely used industrially, compared to other crystalline adsorbents such as metal organic frameworks and activated carbons. In this chapter, we discuss the use of small-pore zeolites in the adsorption and separation of small gases (e.g., CO2, C2H4, C3H6, NOx, etc.), based on how their pore structure, composition, and type of extraframework cations influence the maximum uptake and adsorption kinetics of the target adsorbate. A careful analysis of knowledge accumulated in this field thus far allows us to conclude that small-pore zeolites will likely be further employed in the adsorption/separation of economically useful or noxious small gas molecules. Therefore, there is still a strong need for the synthesis of zeolites with new pore structures and/or compositions, which will in turn lead to improved adsorbents for selective small gas capture.