(225k) Enhancing Cyclic Stability of Calcium-Included Layered Double Hydroxide for CO2 Capture Via Controlling Alkali Metal Portion

Global warming is mainly due to the substantial emission of greenhouse gases (GHGs), and its ascending seriousness has led to the necessity of reducing carbon dioxide gas (CO₂), a major gas among GHGs. A representative CO₂-reduction technology is carbon capture and storage (CCS), a technology in regard to the separation, transportation, and storage of CO₂. Adsorption is included in the separation of CO₂, and the type of adsorbents varies as the adsorption temperature or its application alters. Among numerous adsorbents, calcium-included layered double hydroxide (Ca-LDH) is able to adsorb CO₂ at approximately 600 ^oC, which is included in the range of reforming reaction of natural gas for hydrogen production. This demonstrates that it is advantageous when there is no need to modify the temperature during capturing CO₂, leading its easy application on sorption enhanced reaction. Contrarily, calcium-based adsorbents are commonly so vulnerable that their cyclic stability is hardly attained. In this research, the amount of alkali metal in Ca-LDH varied to enhance the cyclic stability of the adsorbent. Synthesized Ca-LDH was applied in CO₂ adsorption-desorption cycles, and meanwhile, its structural changes and adsorption trends were examined. Furthermore, the relationship between the amount of alkali metal and cyclic stability was clarified.