CO2 Absorption on Na2ZrO3: A Kinetic Analysis of the Chemisorption and Diffusion Processes

详细信息    查看全文

• 作者：Itzel Alc&eacute ; rreca-Corte ; Esteban Fregoso-Israel ; Heriberto Pfeiffer
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：April 24, 2008
• 年：2008
• 卷：112
• 期：16
• 页码：6520 - 6525
• 全文大小：162K
• 年卷期：v.112,no.16(April 24, 2008)
• ISSN：1932-7455

文摘

The kinetics analysis of carbon dioxide (CO₂) chemisorption on sodium zirconate (Na₂ZrO₃), which impliesa sodium diffusion process, was investigated. Initially, Na₂ZrO₃ was analyzed by X-ray diffraction, scanningelectron microscopy, and N₂ adsorption, to characterize the material. Finally, the material was thermallyanalyzed under a CO₂ flux. Later, different isothermal experiments were performed under a CO₂ flux tostudy kinetically the CO₂ chemisorption on Na₂ZrO₃. Results showed that there is a sintering effect of thesample during the heating process. This effect produced, at low temperatures, a decrease in the CO₂chemisorption efficiency. However, at high temperatures, once the sodium diffusion was activated, the sinteringeffect did not interfere with the CO₂ chemisorption process. Modeling the CO₂ chemisorption on Na₂ZrO₃ (interms of a double process: chemisorption and sodium diffusion) allowed us to estimate the activation energyfor these processes, 33 866 J/mol (chemisorption) and 48 009 J/mol (diffusion), which demonstrated that thediffusion process is the limiting step.