Adsorption effect of porous zirconia for carbon dioxide under the influence of various factors

Abstract

Global warming and environmental deterioration have caused socially catastrophic events, arousing people’s interest in discovering the root causes of such events. Looking for an economically efficient and highly adsorbing carbon dioxide adsorbent has become one of the research priorities. Porous zirconia is an ideal candidate material for absorbing CO2 due to its distinctive acid-base property and a large number of active sites. The present study analyzed the effects of external factors (e.g., porous zirconia, including temperature, pH value, and humidity) and internal factors (e.g., crystal structure, lattice defects, and percentage of active sites in zirconia) on the adsorption performance of porous zirconia. Porous zirconia was found to have a high adsorption efficiency at pH 3∼6 under humid conditions. When the crystal structure of zirconia was tetragonal, monoclinic, or tetrahedral, the zirconia had a larger void volume and a larger number of active vacancies and oxygen vacancies. Modifying and increasing oxygen vacancies resulted in a larger number of active sites and a greater Gibbs free energy in the ZrO2 materials and their composites.