Effect of cesium incorporation in hydrotalcite-like compounds

Abstract

Hydrotalcite-like compounds are synthetic anionic clays that have outstanding adsorption and catalytic properties. Hydrotalcite nanoclays (Mg–Al layered hydroxides) were synthesized by co-precipitation method. Obtained solids were converted into mixed metal oxides by thermal decomposition at temperatures up to 723\xa0K. High adsorption and reconstructive properties of the mixed metal oxides allowed incorporating metal ions in their structure. Thus, these materials can be used as ion traps from aqueous media. Cesium ions were incorporated into hydrotalcite lamellar structure by impregnation method. Effects of different loads of Cs+ and adsorption times on the material properties were studied. The materials were characterized by X-ray diffraction, surface area analysis, scanning electron microscopy, energy dispersive X-ray spectrometry for obtaining a localized chemical analysis, and temperature-programmed desorption of CO2 for measurement of basic sites density. The amounts of metal incorporated in the structure was high enough due to small size of Cs+ ion. Synthetized materials also demonstrated high concentrations of strong surface basic sites formed through a synergistic effect of Cs and Mg ions. Basic properties of Cs-containing hydrotalcites enable their potential use as catalysts of base-catalyzed reactions.