Author(s)

Charly Mve Mfoumou^1,2*, Francis Ngoye¹, Pradel Tonda-Mikiela^1,2, Ferdinand Evoung Evoung^1,2, Landry Biyoghe Bi-Ndong^1,2, Thomas Belin³, Samuel Mignard³

¹Laboratoire de Chimie des Milieux et des Matériaux Inorganiques (LC2MI), URCHI/Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon.
²Département de Chimie, Faculté des Sciences, Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon.
³Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), UMR 7285 CNRS/Université de Poitiers, 4 Rue Michel Brunet, Poitiers Cedex, France.

Study of physisorbed and chemisorbed carbon dioxide (CO₂) species was carried out on the NaX zeolite modified by cationic exchanges with bivalent cations (Ca²⁺ and Ba²⁺) by temperature-programmed desorption of CO₂ (CO₂-TPD). Others results were obtained by infrared to complete the study. The results of this research showed, in the physisorption region (213 - 473 K), that the cationic exchanges on NaX zeolite with bivalent cations increase slightly the interactions of CO₂ molecule with adsorbents and/or cationic site. Indeed, the desorption energies of physisorbed CO₂ obtained on the reference zeolite NaX (13.5 kJ·mol^-1) are lower than that of exchanged zeolites E-CaX and E-BaX (15.77 and 15.17 kJ·mol^-1 respectively). In the chemisorbed CO₂ region (573 - 873 K), the desorption energies related to desorbed species (bidentate carbonates: CO₃^2-) on the exchanged zeolites E-CaX and E-BaX are about 81 kJ·mol^-1, higher than the desorbed species (bicarbonates: HCO₃^2-) on the reference R-NaX (62 kJ·mol^-1). In addition, the exchanged E-BaX zeolite develops the secondary adsorption sites corresponding to bicarbonates species with desorption energies of 35 kJ·mol^-1 lower to desorption energies of bicarbonates noted on the reference zeolite NaX.

Adsorption, Faujasite X, Chemisorbed and Physisorbed CO₂, Exchanged Zeolites, Bivalent Cations, Temperature-Programmed Desorption (TPD), Infrared

Mfoumou, C. , Ngoye, F. , Tonda-Mikiela, P. , Evoung, F. , Bi-Ndong, L. , Belin, T. and Mignard, S. (2023) Study of the Temperature-Programmed Desorption of Carbon Dioxide (CO₂) on Zeolites X Modified with Bivalent Cations. Journal of Environmental Protection, 14, 66-82. doi: 10.4236/jep.2023.141005.