TY - JOUR
T1 - Impact of Anodic Oxidation Reactions in the Performance Evaluation of High-Rate CO2/CO Electrolysis
AU - Xu, Qiucheng
AU - Liu, Sihang
AU - Longhin, Francesco
AU - Kastlunger, Georg
AU - Chorkendorff, Ib
AU - Seger, Brian
N1 - The research leading to these results has received funding from the Villum Center for the Science of Sustainable Fuels and Chemicals Grant No. 9455 and research Grant No. 29450, European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 851441 (SELECTCO2), Carlsberg Foundation (EHALIDE, project no. CF19‐0272), and from the Independent Research Fund Denmark (CapCO2 project No. 1127‐00120B).
PY - 2024
Y1 - 2024
N2 - The membrane-electrode assembly (MEA) approach appears to be the most promising technique to realize the high-rate CO2/CO electrolysis, however there are major challenges related to the crossover of ions and liquid products from cathode to anode via the membrane and the concomitant anodic oxidation reactions (AORs). In this perspective, by combining experimental and theoretical analyses, several impacts of anodic oxidation of liquid products in terms of performance evaluation are investigated. First, the crossover behavior of several typical liquid products through an anion-exchange membrane is analyzed. Subsequently, two instructive examples (introducing formate or ethanol oxidation during electrolysis) reveals that the dynamic change of the anolyte (i.e., pH and composition) not only brings a slight shift of anodic potentials (i.e., change of competing reactions), but also affects the chemical stability of the anode catalyst. Anodic oxidation of liquid products can also cause either over- or under-estimation of the Faradaic efficiency, leading to an inaccurate assessment of overall performance. To comprehensively understand fundamentals of AORs, a theoretical guideline with hierarchical indicators is further developed to predict and regulate the possible AORs in an electrolyzer. The perspective concludes by giving some suggestions on rigorous performance evaluations for high-rate CO2/CO electrolysis in an MEA-based setup.
AB - The membrane-electrode assembly (MEA) approach appears to be the most promising technique to realize the high-rate CO2/CO electrolysis, however there are major challenges related to the crossover of ions and liquid products from cathode to anode via the membrane and the concomitant anodic oxidation reactions (AORs). In this perspective, by combining experimental and theoretical analyses, several impacts of anodic oxidation of liquid products in terms of performance evaluation are investigated. First, the crossover behavior of several typical liquid products through an anion-exchange membrane is analyzed. Subsequently, two instructive examples (introducing formate or ethanol oxidation during electrolysis) reveals that the dynamic change of the anolyte (i.e., pH and composition) not only brings a slight shift of anodic potentials (i.e., change of competing reactions), but also affects the chemical stability of the anode catalyst. Anodic oxidation of liquid products can also cause either over- or under-estimation of the Faradaic efficiency, leading to an inaccurate assessment of overall performance. To comprehensively understand fundamentals of AORs, a theoretical guideline with hierarchical indicators is further developed to predict and regulate the possible AORs in an electrolyzer. The perspective concludes by giving some suggestions on rigorous performance evaluations for high-rate CO2/CO electrolysis in an MEA-based setup.
U2 - 10.1002/adma.202306741
DO - 10.1002/adma.202306741
M3 - Journal article
C2 - 37880859
AN - SCOPUS:85174849988
SN - 0935-9648
VL - 36
JO - Advanced Materials
JF - Advanced Materials
IS - 2
M1 - 2306741
ER -