Recently, Wang Guoxiong and Gao Dunfeng, researchers of the Electrocatalytic Conversion Research Group of Carbon based Resources in the State Key Laboratory of Catalysis Foundation, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, cooperated with Anqing, a professor of Dalian University of Technology, and made new progress in the research of carbon dioxide (CO2) electrolysis for fuel and chemicals, realizing the efficient production of CO by direct electrolysis of low concentration CO2, providing a new idea for the resource utilization of CO2 in industrial waste gas.
CO2 electrolysis is a promising negative carbon technology that can convert CO2 from industrial waste gases such as flue gas into high-value fuels and chemicals. Currently, pure CO2 feed gas is commonly used in CO2 electrolysis research, while the concentration of CO2 in industrial waste gases such as flue gas generated from fossil fuel combustion is relatively low. The energy consumption and investment cost of capturing and purifying CO2 from flue gas are high, which reduces the economic feasibility of CO2 electrolysis technology. Direct electrolysis of low concentration CO2 can significantly reduce the separation and purification cost of obtaining high concentration CO2, but the decrease in CO2 concentration makes efficient CO2 electrolysis more challenging. Therefore, achieving efficient CO2 electrolysis for fuel and chemical production under low CO2 concentration conditions is of great significance.
The team utilized molecular modification strategies to construct a reaction microenvironment that effectively couples CO2 capture and conversion processes, achieving direct electrolytic conversion of low concentration CO2. This study used commercial CoPc as a model catalyst and modified the electrode with poly (4-vinylpyridine) (P4VP). At a typical industrial flue gas CO2 concentration of 10%, the CO Faraday efficiency of the P4VP modified CoPc electrode reached over 90%, and the CO partial current density reached 252 mA/cm2. The CO partial current density was 2.24 times higher than that of the unmodified CoPc electrode. The results of physicochemical and electrochemical structural characterization indicate that the pyridine group of P4VP promotes the physical enrichment and chemical activation of CO2 at Co sites in CoPc catalysts, promoting the electrolysis of low concentration CO2 to generate CO. Combined with further catalyst structure design and reaction microenvironment regulation, this molecular enhancement strategy is expected to achieve efficient preparation of industrial flue gas direct electrolysis and C2+products such as ethylene.
The relevant research results are titled Molecular Enhancement of Direct Electrolysis of Dilute CO2 and published in the ACS Energy Letters. The research work has received support from the National Key R&D Program, National Natural Science Foundation of China, Liaoning Xingliao Talent Program, Dalian Institute of Chemical Physics Innovation Fund, and the Energy Materials Chemistry Collaborative Innovation Center of the Ministry of Education.
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Dalian Institute of Chemical Physics and others proposed a new strategy for direct electrolytic conversion of low concentration carbon dioxide
