Interlayer Cation-Controlled Adsorption of Carbon Dioxide in Anhydrous Montmorillonite Clay

Widely available natural layered expandable clay minerals (smectites) can sorb carbon dioxide in their interlayer space under specific conditions and hence may show potential for gas separation or sequestration processes. This work presents experimental adsorption desorption measurements of gaseous, sub-critical (p = 0.1 bar up to 20 bar, T ?20 °C 300 °C) on well-characterized anhydrous smectite (Wyoming montmorillonite) focuses the effect cation (size). Using seven alkali alkaline-earth metal cations three quaternary ammonium cations, a wide range ionic radii are studied. Physisorption CO2 is confirmed via infrared spectroscopy measurements. The results that optimally sized cations?comparable thickness monolayer?open make it easily accessible 1.7 mmol g–1. In particular, Cs-exchanged tetramethylammonium-exchanged montmorillonite facilitate rapid sorption even at ambient pressure temperature. These provide valuable insights into applicability widely adsorbent clays capture mitigation climate change.