2024-03-28T13:39:48Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/500342022-11-17T02:08:08Zhdl_2115_20045hdl_2115_139CO2 decomposition using electrochemical process in molten saltsOtake, KoyaKinoshita, HiroshiKikuchi, TatsuyaSuzuki, Ryosuke O431The electrochemical decomposition of CO2 gas to carbon and oxygen gas in LiCl-Li2O and CaCl2-CaO molten salts was studied. This process consists of electrochemical reduction of Li2O and CaO, as well as the thermal reduction of CO2 gas by the respective metallic Li and Ca. Two kinds of ZrO2 solid electrolytes were tested as an oxygen ion conductor, and the electrolytes removed oxygen ions from the molten salts to the outside of the reactor. After electrolysis in both salts, the aggregations of nanometer-scale amorphous carbon and rod-like graphite crystals were observed by transmission electron microscopy. When 9.7 %CO2-Ar mixed gas was blown into LiCl-Li2O and CaCl2-CaO molten salts, the current efficiency was evaluated to be 89.7 % and 78.5 %, respectively, by the exhaust gas analysis and the supplied charge. When a solid electrolyte with higher ionic conductivity was used, the current and carbon production became larger. It was found that the rate determining step is the diffusion of oxygen ions into the ZrO2 solid electrolyte.IOP PublishingJournal Articleapplication/pdfhttp://hdl.handle.net/2115/50034https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/50034/1/JoPCS379-1_012038.pdf1742-6596Journal of Physics: Conference Series37910120382012enginfo:doi/10.1088/1742-6596/379/1/012038Published under licence in Journal of Physics: Conference Series by IOP Publishing Ltd.publisher