Studies On Preparation Of Nano-cerium Oxide-based Adsorbents And Their Adsorption To Carbon Dioxide

With the accelerating the global industrialization process,the consumption of fossil fuels and other energy sources are increasing,and CO₂ emissions are also increasing.As a result,climate warming,rising sea levels,and the melting of icebergs have caused great concern in various countries.How to reduce CO₂ emission and convert them into energy,materials,and high value-added chemicals is of great significance.In this work,ethylenediamine?EDA?+ethylene glycol?EG?system was selected for CO₂ capture,activation and conversion to a new type of CO₂ storage material?CO₂SM?,and this has developed a green new type of CO₂ capture and resource utilization?CCU?method.First,based on the capture of CO₂ by the EDA+EG system,the white solid was formed as an alkyl ammonium carbonate salt,which was defined as CO₂SM.CO₂SM could release CO₂,EDA and EG under heating conditions.CO₂ could be dissolved in water to form carbonate,providing a new idea for the preparation of metal carbonates.The remaining EDA and EG systems could reabsorb CO₂,opening up a new way for the cyclic production of metal carbonates.Second,the hydrothermal method was used to focus on the process of indirect mineralization of CO₂ into metal carbonates.The CeCO₃OH was prepared by the reaction of CO₂SM and cerium chloride solution,and the effects of CO₂SM content,reaction temperature,reaction time,and cerium ion concentration on CeCO₃OH were investigated.Finally,three uniform morphologies of CeCO₃OH with nanostructured?bow-tie-like,comet-like,dandelion-like?were obtained.CeO₂ was prepared by calcining CeCO₃OH,and CO₂ was further adsorbed at room temperature using CeO₂.In order to simplify the preparation process,the preparation of cerium carbonate by stirring was investigated.Finally,a flaky-like nanostructured cerium metal carbonate was obtained and further calcining to prepare flaky-like nanometer CeO₂,and the ability to capture CO₂ was investigated.The results showed that the flaky-like nano-CeO₂ exhibited certain adsorption properties for CO₂.In order to improve the CO₂ adsorption performance of CeO₂,the preparation process of Ce-Ca composite carbonate stirring method was also investigated.After calcination,Ce-Ca composite oxides were obtained.The performance of CO₂adsorption was investigated.The results showed that Ca doping significantly improves the adsorption of CO₂ by CeO₂.Finally,the paper proposed a simple green method without external template to prepare metal carbonates and then prepared metal oxides.During the experiment,CO₂SM could not only be used as a source of carbonate,but also as a crystal regulator to regulate the nucleation,crystallization,growth,morphology and crystal form of metal carbonates.Filtrate without precipitate not only could recycle absorption of CO₂,but also could realize the cyclic production of uniform metal carbonate.By studying the interaction between ions and molecules in the system,the crystal growth mechanism was proposed.The entire process integrated CO₂ capture,storage and resource utilization,providing reference and ideas for the development of new technologies.