| Abstract
| - Adsorption of carbon dioxide on parent and alkaline-modified Y zeolites was investigated by temperature-programmed desorption (TPD) analysis of these materials previously saturated with CO2 at differenttemperatures (50−200 °C). Parent zeolite was treated with different sodium and cesium aqueous solutions,using both carbonates and hydroxides as precursors. Morphological, crystallographic, and chemical propertiesof these materials were determined by nitrogen physisorption, X-ray diffraction (XRD), Fourier transforminfrared (FTIR) spectroscopy, inductively coupled plasma (ICP), X-ray photoelectron spectroscopy (XPS),and NH3-TPD. Slight desilication phenomena were observed when hydroxides were used as precursors, whereasthe treatment with Cs salts leads to higher crystallinity losses. Several successive adsorption−desorptioncycles were carried out in order to check the stability of the adsorbents. Both Cs treatments lead to anenhancement of the retention capacity when adsorption is carried out at the highest temperatures (100−200°C), whereas Na treatments hardly affect adsorption properties of the parent material. The evolution of theretention capacity of carbon dioxide after water adsorption−desorption was also studied. It was observed thatwater pretreatment enhances the adsorption capacity of the Cs-treated zeolites.
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