System Design in CO2 Electrolysis: Integrating Value-Added Anode Reactions with Cathodic Reduction

Paired electrolysis represents a paradigm shift in overcoming the energy intensity of conventional CO₂ electrolysis. By supplanting the oxygen evolution reaction with value-added anodic oxidations, this technology simultaneously slashes energy demands and diversifies output. This review critically synthesizes design principles for pairing these anodic reactions with two key cathode pathways, namely CO₂ electroreduction and electrocarboxylation, supported by an analysis of pioneering systems from the past three years. We further explore advanced reactor designs for co-production, and the pivotal role of operando characterization and machine learning in unraveling complex mechanisms. We conclude with a perspective on the key challenges and pathways to industrial adoption, aiming to bridge fundamental advances with practical implementation.