Metal–Organic Frameworks for Electrocatalytic CO₂ Reduction: Developments and Prospects

The urgent need to reduce carbon emissions has intensified research into carbon dioxide (CO 2 ) conversion systems, with electrochemical reduction emerging as a promising approach. Efficient electrocatalysts are crucial for the challenging conversion of CO 2 into valuable products. Metal–organic frameworks (MOFs) have garnered significant attention as electrocatalysts for CO 2 electrolysis due to high surface areas, permanent porosity, modularity, and tunability. The exceptional tunability of MOFs enables precise engineering of the chemical environment surrounding the active site, facilitating a deeper understanding of structure–activity relationships for CO 2 reduction. This review catalogues diverse MOF-based electrocatalyst designs for CO 2 reduction, categorizing them into distinct generations based on active site structures. The first generation utilizes traditionally insulating metal node or linker components as the active site. The second generation uses a single atom active site embedded onto the organic linker. The third generation utilizes active sites within electrically conductive MOFs. Additionally, this review identifies specific enhancements that boost the electrocatalytic performance of MOF-based systems, including experimental setup optimization, host–guest interactions, secondary sphere interactions and photoassistance. Understanding how these enhancements overcome electrocatalytic limitations and improve performance will guide the development of high-performing MOF electrocatalyst systems for efficient CO 2 conversion.