Investigating and optimizing water management and cation crossover in membrane electrode assembly CO2 electrolyzers

CO2 electrolysis (CO2E) based on the membrane electrode assembly (MEA) configuration has attracted great attention for synthesizing value-added chemicals. However, MEA-based CO2E often suffers from poor stability and selectivity variations. Flooding of gas diffusion electrode (GDE) and the formation of salt precipitation in the GDE cause CO2 mass transport limitations at the catalyst layer, which in turn increases competitive hydrogen evolution reaction. These results indicate that the structure of catalyst layer (CL) and ion transport mechanism of anion exchange membrane (AEM) could largely influence both flooding and salt precipitation in the GDE. In this proposal, we expect proper hydrophobicity of CL and permeability of AEM could alleviate the flooding/salt precipitation by regulating accessibility of water transport from the anode side. We plan to employ different GDEs with varying hydrophobicity of CL and different AEMs with varying water uptake to optimize the water transport.