Adsorption of the rare earth elements cerium, lanthanum, and neodymium onto ZSM-5 zeolite: A statistical physics approach

• Published in: Journal of molecular liquids 2024-07, Vol.405, p.125035, Article 125035
• Main Authors: Ferreira Piazzi Fuhr, Ana Carolina, Pinto, Diana, Felipe Oliveira Silva, Luis, Hessien, Mahmoud M., Alshammari, Dalal A., El-Bahy, Zeinhom M., Luiz Dotto, Guilherme
• Format: Article
• Language: English
• Subjects: Adsorption; Isotherms; Mechanism; Rare earth elements; Statistical physic models
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2024.125035

•ZSM-5 zeolite synthesized using chitin as a molding agent has the potential to recover rare earth elements;•Increasing the temperature decreased the adsorption amount of rare earth elements;•The Ce, La, and Nd removal process forms a monolayer in zeolite;•Si-functional groups predominate in the rare earth element removal;•Electrostatic interactions and the formation of complexes were involved in Ce, La, and Nd adsorption onto zeolite. The recovery of rare earth elements (REE) is essential to meet the growing demand for these resources and promote the reuse of available resources. This study investigated the potential of ZSM-5 zeolite in the recovery of trivalent ions of cerium, lanthanum and neodymium under conditions of pH 6 and temperatures between 298 and 328 K. REE equilibrium isotherms were analyzed using five statistical physics models. The results indicate that removing all REE occurs predominantly in monolayers, as these models showed better prediction performance (coefficient of determination > 0.97 and mean squared error  cerium > lanthanum. The adsorption energies indicate that the process occurred mainly due to physical forces since all energy values are below 40 kJ mol−1. The study’s results led to the proposal of a mechanism for the adsorption of REE on ZSM-5 zeolite, which highlights the predominance of electrostatic interactions and complex formation, which result in the formation of a monolayer on the adsorbent’s surface.