Structural and Ionic Conduction Analyses of the Na₂(Zr1–xAlx)O3–x/2 Solid Solution, During the CO₂ Chemisorption Process

To determine the influence of the aluminum content in the sodium zirconate during the CO 2 chemisorption process, specific compositions in the Na 2 (Zr 1– x Al x )O 3– x /2 solid solution were produced. The synthesis was performed in order to restrict the aluminum crystalline sites to tetrahedral positions, substituting zirconium atoms. Samples were characterized using X-ray diffraction, N 2 adsorption–desorption and 27 Al solid-state nuclear magnetic resonance. Then, samples were tested as CO 2 captors using dynamic and isothermal analyses. Additionally, ionic conduction experiments were performed in different sodium containing phases to determine the effect of these phases in the CO 2 chemisorption process. Results showed that there are several factors that determine the CO 2 chemisorption in the pristine Na 2 ZrO 3 and compounds of the Na 2 (Zr 1– x Al x )O 3– x /2 solid solution. Some of these factors are the presence or absence of different structural vacancies, as well as the presence of different phases in the carbonated external shell.