Oxygen Evolution Reaction Catalysts for Acidic‐Media CO 2 Electrolyzers

ABSTRACT Acidic‐media electrochemical CO 2 reduction (CO 2 R) offers high single‐pass CO 2 conversion (SPCE) and low purification cost, yet relies on scarce noble metals (e.g., iridium and ruthenium) for the anodic oxygen evolution reaction (OER). The limited abundance of these catalysts constrains large‐scale deployment. Drawing lessons from proton‐exchange membrane water electrolysis (PEMWE), this review integrates recent progress in acidic‐media OER catalysis with system‐level CO 2 R. It provides a cross‐scale perspective from mechanistic understanding and theoretical modeling to electrode architecture and operational optimization, highlighting how noble‐ and non‐noble‐metal catalysts can be engineered for enhanced activity, stability, and resource efficiency. The review further outlines diagnostic and computational approaches that connect atomic‐level descriptors with macroscopic durability. By bridging mechanistic insights and scalable system design, this work establishes a roadmap toward durable and economically viable acidic‐media CO 2 electrolyzers.