Hydration mechanism in Ce-exchanged zeolites and heat release performances upon adsorption of water vapour in support of their potential use in thermochemical storage of energy under mild conditions of adsorbent regeneration and saturation

Hao Wu (1) , Philippe Trens (1) , Bernard Fraisse (1) , Fabrice Salles (1) , Jerzy Zajac (1)

1 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier

The potential use of commercially available 13X zeolite, modified by ion-exchange with cerium compensating cations possessing high charges and high hydration energies, has been tested in view of low-temperature storage of solar energy performed under mild operating conditions of low regeneration temperatures and low pressures of water vapour during the adsorption step. Structural and textural properties, sorption behaviour towards water vapour of three selected samples containing various proportions of Ce 3+ and Ce 4+ compensating cations and the pristine Na +-13X zeolite were studied by a variety of experimental techniques including Wavelength Dispersive X-Ray Fluorescence, Energy Dispersive X-ray Spectroscopy, X-ray diffraction, Thermogravimetric analysis, as well as measurements of the adsorption of gaseous nitrogen at 77 K and water vapour at 313 K. Based on the structure refinement procedure applied to the experimental XRD patterns, it was demonstrated that extra-framework cerium cations were preferentially located on sites I' and II in dry and hydrated zeolites, showing relatively little dependence on the hydration level. Monte Carlo simulations were used to determine the limit values of the amount adsorbed and differential

Mots clés: heats of adsorption; mild adsorbent regeneration and saturation; Monte Carlo simulations; thermochemical energy storage; gas flow calorimetry; adsorption isotherms; cation distribution; water vapour adsorption; trivalent and tetravalent cerium; 13X zeolite; cation exchange

Domaines: Matériaux

Hao Wu, Philippe Trens, Bernard Fraisse, Fabrice Salles, Jerzy Zajac. Hydration mechanism in Ce-exchanged zeolites and heat release performances upon adsorption of water vapour in support of their potential use in thermochemical storage of energy under mild conditions of adsorbent regeneration and saturation. Microporous and Mesoporous Materials, 2020, 296, pp.109999. ⟨10.1016/j.micromeso.2020.109999⟩. ⟨hal-02441944⟩