Comparative study on Cs+ ion-exchange behavior in zeolites with different framework structures and compositional characteristics

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In this study, we investigate the Cs + ion-exchange behavior of eight zeolites (K-A, Na-A, Ca-A, Na-X, Na-Y, Na-mordenite, Na-ZSM-5, and Na-SSZ-13) with varying framework structures, SiO 2 /Al 2 O 3 ratios, and Brønsted acidity. Experimental results demonstrate that Na-type zeolites undergo a 1:1 ion-exchange reaction with Cs + . Additionally, Na-type zeolites exhibited significantly higher Cs + exchange capacities compared to K-type and Ca-type zeolites. Zeolites containing 8-membered rings (8 MR) and those with high SiO 2 /Al 2 O 3 ratios showed enhanced Cs + ion-exchange selectivity. Brønsted acidity significantly promoted Cs + exchange in Na-mordenite and Na-ZSM-5, but had little effect on LTA and FAU. These findings clarify the structural and chemical factors influencing Cs + ion-exchange and provide valuable insights for designing optimized zeolites for radioactive Cs + removal. • Na-type zeolites exhibit high Cs + ion-exchange capacities through a 1:1 ion-exchange reaction. • Zeolites containing 8 MR and a high SiO 2 /Al 2 O 3 ratio exhibited superior Cs + selectivity. • Brønsted acidity enhanced Cs + ion-exchange in MOR and MFI, but showed little effect on LTA and FAU.