Advancing CO2 electrolyzers from laboratory to industrial scale

Electrochemical CO 2 reduction reaction (CO 2 RR) driven by renewable energy represents a pivotal strategy for closing the anthropogenic carbon cycle. While catalyst development has advanced rapidly, the shift of intrinsic activities into industrial productivity is strictly governed by electrolyzer engineering. This review critically assesses the evolution of CO 2 RR reactor configurations, moving from fundamental kinetic studies in H-cells to high-rate production in gas-fed systems including flow cells, membrane electrode assemblies, and emerging solid electrolyte/stacked systems. Particular attention is given to the physicochemical trade-offs and engineering bottlenecks hindering scale-up. Finally, we propose a strategic roadmap for future research, with the emphasis of dynamic operation, impurity tolerance, operando characterization techniques, and the integration of techno-economic analysis into future reactor design. • The main types of CO 2 RR electrolyzers from laboratory to industrial scale are overviewed. • The key physicochemical and engineering bottlenecks are discussed. • Strategic insights are provided for designing next-generation CO 2 electrolyzers.