Analysis of the interaction of CO2 with Na, K, and Ca-exchanged Mordenite. An infrared spectroscopic study

To enquire on the CO2 capture on solid adsorbents, the interactions of CO2 with mordenite exchanged with Na, K, and Ca were analyzed using FTIR spectroscopy. The results reveal that physisorbed CO2 and different carbonate species are present on the zeolite surface. At high CO2 concentration, the cation polarizing power determines the type of carbonates formed: mainly bidentate carbonates on Ca-mordenite; bi and polydentate carbonates on Na-mordenite; polydentate carbonates on K-mordenite. At low CO2 (10-4 Torr), mostly bidentate carbonates are formed. Pre-adsorbed water produces bicarbonates and decreases CO2 adsorption.