Abstract

SANDOVAL-DIAZ, A  and  PFEIFFER, H. Effects of potassium doping on the composition, structure and carbon dioxide chemisorption of Na₂Zr0₃. Rev. mex. fis. [online]. 2008, vol.54, n.1, pp.65-68. ISSN 0035-001X.

Solid solutions of sodium and potassium metazirconate, Na_2-x;K_x;ZrO₃, were prepared by coprecipitation. Then, samples were characterized by powder X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. Results show that the solubility limits of potassium in Na₂ZrO₃ is 0.2, Na_1.8K_0.2ZrO₃, and the addition of potassium produced the formation of needle-like particles. Furthermore, Na_2-x;K_x;ZrO₃ solid solutions were tested as CO₂ captors. The analyses of these materials showed that, although all the solid solutions present similar behaviors, the chemisorption and diffusion kinetics were enhanced by the addition of potassium. Na_1.6K_0.4ZrO₃ seems to be the best solid solution for the CO₂ capture. The differences observed in the CO₂ sorption processes were explained by the different ionic radii of sodium and potassium and with thermodynamic data.

Keywords : Absorption; carbon dioxide; sodium and potassium zirconate.