Synthesis of “Ice Cube” Shaped Zeolite A Type and Cu²⁺ Ion-Exchanged Zeolites and Study of Their CO₂ Adsorption Performance

In this study, zeolite type A and four Cu²⁺ ion-exchanged zeolites were synthesized through cationic ion exchange process with Cu concentrations of 0.05, 0.1, 0.15, and 0.2 M respectively. The physicochemical properties of both the prepared and ion-exchanged zeolites were thoroughly analyzed. Field Emission Scanning Electron Microscopy (FESEM) micrographs revealed that the synthesized zeolites exhibited an "ice cube"-shaped morphology, and this morphology was maintained even after the ion exchange process. N₂ adsorption/desorption studies indicated a typical type IV isotherm with an H3 hysteresis loop for both the prepared and Cu²⁺ ion-exchanged zeolites. CO₂ adsorption data followed a type I isotherm, with the highest adsorption capacity of 4.02 mmol/g observed for the 0.1 M Cu²⁺ ion-exchanged zeolites. The adsorption behavior was modeled using a nonlinear isotherm, with good agreement between experimental and fitted data.