Lan, M.Ren, W.2025-07-242025-07-242025Next Materials, 2025; 6:100506-1-100506-72949-82282949-8228https://hdl.handle.net/2440/146290Available online 28 January 2025Membrane electrode assembly (MEA) electrolyzers for carbon dioxide reduction reaction (CO2RR) present a transformative approach for reducing CO2 emissions while producing valuable chemicals. However, their commercialization is still hindered by several inherent challenges. This review outlines these critical bottlenecks and highlights recent advances aimed at enhancing the performance of CO2R MEA electrolyzers. First, the in-situ generated carbonate and bicarbonate species at the cathode can migrate to the anode or form salt precipitates, which reduces carbon efficiency (CO2-to-products) and obstructs gas diffusion channels. Second, product crossover can be diluted or even re-oxidized at the anode, resulting in increased energy consumption for product separation and electrolyte regeneration. Finally, the stability of CO2R MEA electrolyzers, particularly when producing multi-carbon (C2+) products, remains far insufficient for commercial viability, as degradation of the catalyst layer, gas diffusion electrode, and anolyte significantly impacts performance. To address these challenges, this review identifies potential solutions and future directions, including pure-water-fed strategy, hydrophobic catalyst layer designs, and membrane customization.en© 2025 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Membrane electrode assembly; CO2 reduction; Electrochemistry; CatalysisJournal article10.1016/j.nxmate.2025.100506727682Lan, M. [0000-0002-7855-1908]Ren, W. [0000-0002-8769-3131]