(Invited) Electrochemical Conversion of CO2 Into Oxygen/ and C/CO in Molten Carbonate

Abstract

The molten salt CO 2 capture and electrochemical transformation (MSCC-ET) process has been demonstrated as an effective approach to capturing and converting CO 2 into oxygen and C/CO [1-2]. The effective CO 2 capture and electrochemical conversion rely on the high-temperature molten carbonate electrolytes and the cost-effective inert oxygen-evolution anode. In recent years, we have focused on the electrolyte engineering to modulate the reactions at both the cathode and anode as well as the CO 2 capture efficiency [3-4]. Besides, we insist on developing iron- and nickel-base oxygen-evolution inert anodes in terms of revealing the fundamental principles and basic guidelines for choosing proper materials and fabrication processes [5]. By doing so, we can prepare functional carbon materials or CO at the cathode with a high current efficiency of over 90%, and produce oxygen at the inert anode. In addition, the kilo-ampere scale electrolyzer was built to produce oxygen, carbon or CO with an energy efficiency of over 50%. Therefore, the molten carbonate CO 2 electrolyzer shows its potential to convert CO 2 on the Mars to produce oxygen and fuels to support the future exploration of outer space. References [1] H. Y. Yin, D. H. Wang*, et al., Capture and electrochemical conversion of CO 2 to value-added carbon and oxygen by molten salt electrolysis. Energy & Environmental Science, 2013, 6: 1538-1545. [2] R. Jiang, M. X. Gao, X. H. Mao, D. H. Wang*. Advancements and potentials of molten salt CO 2 capture and electrochemical transformation (MSCC-ET) process, Current Opinion in Electrochemistry, 2019, 17: 38-46. [3] B. W. Deng, J. J. Tang, X. H. Mao, Y. Q. Song, H. Zhu, W. Xiao, D. H. Wang*. Kinetic and Thermodynamic Characterization of Enhanced Carbon Dioxide Absorption Process with Lithium Oxide-Containing Ternary Molten Carbonate, Environmental Science & Technology, 2016, 50(19): 10588-10595. [4] Z. S Yang, B. W. Deng, K. F. Du, H. Y. Yin*, D. H. Wang*, A general descriptor for guiding the electrolysis of CO2 in molten carbonate, 2022, in press. [5] P. L. Wang, K. F. Du, Y. P. Dou, H. Zhu, D. H. Wang*, Corrosion behaviour and mechanism of nickel anode in SO42- containing molten Li2CO3-Na2CO3-K2CO3. Corrosion Science 2022, 166. Figure 1