Facile Synthesis of La-modified CeO₂ with Microwave Method for CO₂ Adsorption

CO₂ capture in air is an important issue nowadays. Cerium oxide has been reported to be a good adsorbent for CO₂. However, its adsorption capacity and adsorption strength are not high enough. La-modified CeO₂ was used in this study. In this study: a new adsorbent La-modified CeO₂ solid solution were prepared from aqueous solution of cerium and lanthanum hydroxides by microwave method. These hydroxides were prepared by precipitation of Ce(NO₃)₃ and La(NO₃)₃ solution. The materials were characterized by powder X-ray diffraction, energy dispersive X-ray spectroscopic, scanning electron microscopy, infrared spectroscopy, and nitrogen sorption. The results show that the increasing the lanthanum content leads to a reduction in particle size, and increase in the number of oxygen vacancies in the crystalline structure and the specific BET surface areas of the samples. The La-CeO₂ materials contained impurities of nitrate ions in their structure and exhibited high adsorption properties for carbon dioxide at room temperature. The adsorption of carbon dioxide on the materials were in the form of bidentate. La-modified CeO₂ has large amount of CO₂ adsorption compared to the unmodified one.