Influence of the Compensating Cation Nature on the Water Adsorption Properties of Zeolites

Molecules

Julien Klein¹  Patrice Forler¹  Zakaria Tahraoui²  T.Jean Daou²  Claire Marichal²  Habiba Nouali² 

[1] APTAR CSP Technologies, 9 rue de Sandholz, 67110 Niederbronn-Les Bains, France;Department Institut de Science des Matériaux de Mulhouse IS2M, Université de Haute Alsace (UHA), CNRS, UMR 7361, F-68100 Mulhouse, France;

关键词: zeolite;    lta-type zeolite;    fau-type zeolite;    cationic exchange;    magnesium;    lithium;    water adsorption;   

DOI  :  10.3390/molecules25040944

来源: DOAJ

【 摘 要 】

The influence of the compensating cation (Na⁺, Li⁺, Mg²⁺) nature on the water adsorption properties of LTA and FAU-type zeolites was investigated. Cation exchanges were performed at 80 °C for 2 h using 1 M aqueous solutions of lithium chloride (LiCl) or magnesium chloride (MgCl₂). XRF and ICP-OES analyses indicate that the cation exchange yields reach values between 59 to 89% depending on the number of exchange cycles and the nature of the zeolite and cation, while both zeolites structures are preserved during the process, as shown by XRD and solid state NMR analyses. Nitrogen adsorption-desorption experiments indicate a higher available microporous volume when sodium cations are replaced by smaller monovalent lithium cations or by divalent magnesium cations because twice less cations are needed compared to monovalent cations. Up to 15% of gain in the available microporous volume is obtained for FAU-type zeolites exchanged with magnesium cation. This improvement facilitates the adsorption of water with an increase in the water uptake up to 30% for the LTA and FAU type zeolites exchanged with magnesium. These exchanged zeolites are promising for uses in water decontamination because a smaller amount is needed to trap the same amount of water compared to their sodium counterparts.

【 授权许可】

Unknown