MgAl Hydrotalcite-derived Mixed Oxides for CO2 Adsorption
| Autor: | D., Chaillot, Folliard, V., J., Miehé-Brendlé, Auroux, A., S., Bennici |
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| Přispěvatelé: | IRCELYON-Approches thermodynamiques, analytiques et réactionnelles intégrées (ATARI), Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), IRCELYON, ProductionsScientifiques |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Nordic Clay Meeting / 3rd Symposium Clays & Ceramics 2021 Nordic Clay Meeting / 3rd Symposium Clays & Ceramics 2021, Feb 2021, Riga, Latvia |
| Popis: | SSCI-VIDE+ATARI+VFO:AAU; International audience; Layered Double Hydroxides (LDHs) and LDH-derived materials are potentially good adsorbents for CO2. Moreover, they are relatively cheap, they are easy to synthesize, they present high sorption capacity, and surface basicity. They have been intensively studied in CO2 capture at high temperature, presenting variable sorption capacities for MgAl LDHs with the same composition, but prepared under different synthesis conditions. The sol-gel synthesis method is an attractive one-step procedure to synthesize LDHs under mild conditions, with low energy consumption and short synthesis time. The present study is based on the synthesis of hydrotalcites (HTs) by sol-gel process for CO2 adsorption. The structural and physico-chemical properties of the as-synthesized and calcined HTs have been deeply characterized. Moreover, the effect of the surface basicity and the CO2 sorption capacity have been investigated.Adsorption calorimetry was applied for determining the concentration (from the adsorption volumetric isotherms), strength and strength distribution (using the differential heat of adsorption as a function of coverage) of the basic sites involved in CO2 adsorption. The hydrotalcite-derived mixed oxides surface basicity was probed by adsorption calorimetry of SO2.Two population of basic sites were identified, at low energy (heat of adsorption below 60 kJ/mol) and high energy (heat of adsorption higher than 150 kJ/mol). The sol-gel method led to the formation of hydrotalcites with similar (sometimes higher) performances than conventional LDHs prepared by time and energy consuming methods (like coprecipitation). The calcined hydrotalcites exhibit CO2 adsorption capacities of around 0.5 mmol/g, a value similar to those reported in the literature for sample generally synthesized by coprecipitation (see figure).A linear correlation between the surface basicity (concentration of low and high energy sites) and the adsorption capacity was found. The possibility to tune the Mg/Al molar ratio is a promising feature to obtain a wide range of LDHs (with various surface basicity) with a higher efficiency in CO2 adsorption.Acknowledgments: This work was supported by Université de Haute Alsace and École Doctorale Physique et Chimie- Physique (ED 182). XRD, NMR, XRF, BET, TGA, were performed on the technical platforms of IS2M. |
| Databáze: | OpenAIRE |
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