Impact of Ce/Zr Ratio in the Nanostructured Ceria and Zirconia Composites on the Selective CO(2) Adsorption

High surface-area, mesoporous CeO(2), ZrO(2,) and Ce-Zr composite nanoparticles were developed using the hydrothermal template-assisted synthesis method. Samples were characterized using XRD, N(2) physisorption, TEM, XPS, and FT-IR spectroscopic methods. The CO(2) adsorption ability of the obtained materials was tested under dynamic and equilibrium conditions. A high CO(2) adsorption capacity in CO(2)/N(2) flow or CO(2)/N(2)/H(2)O was determined for all studied adsorbents depending on their composition flow. A higher CO(2) adsorption was registered for Ce-Zr composite nanomaterials due to the presence of strong O(2−) base sites and enriched surface oxygen species. The role of the Ce/Zr ratio is the process of the formation of highly active and selective adsorption sites is discussed. The calculated heat of adsorption revealed the processes of chemisorption and physisorption. Experimental data could be appropriately described by the Yoon–Nelson kinetic model. The composites reused in five adsorption/desorption cycles showed a high stability with a slight decrease in CO(2) adsorption capacities in dry flow and in the presence of water vapor.