Current Potentials and Challenges in Designing Co-Electrolysis Systems for CO2 Conversion

Kuan-Wen Chen; Ching-Han Lu; Bor-Yih Yu

doi:10.53941/gefr.2026.100009

Abstract

Electrochemical CO₂ reduction (ECO₂RR) provides a promising route for its conversion into fuels and value-added chemicals using renewable electricity. Recent advancements have explored the integration of cathodic ECO₂RR with various anodic organic oxidation reactions (OOR) to enhance economic feasibility and lower operating potentials. However, process-level insights into these integrated systems remain largely unexplored. The numerous potential combinations of ECO₂RR and OOR make it impractical to conduct detailed process designs for every pairing. In this paper, we review existing half-reaction experiments and establish a framework to screen for potential integrations of OOR and ECO₂RR based on reported technical feasibility and economic margins. From our framework, we have identified seven candidate pairing systems, predominantly demonstrating economic margins ranging from $0.1 to $0.4 per kg of product. In addition, we highlight the practical challenges encountered in downstream processing, particularly the recovery of ionic products from dilute reaction media. Overall, we conclude that co-electrolysis is economically viable when the added value from the anodic reaction provides sufficient margins to offset downstream separation and purification costs (e.g., pairing methanol and glycolic acid production), or when both half-reactions yield identical products (e.g., formate), which significantly simplifies downstream processing.

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