Carbon Catalysts for Electrochemical CO₂ Reduction toward Multicarbon Products

Electrochemical CO₂ reduction offers a compelling route to mitigate atmospheric CO₂ concentration and store intermittent renewable energy in chemical bonds. Beyond C₁, C₂₊ feedstocks are more desirable due to their higher energy density and more significant market need. However, the CO₂-to-C₂₊ reduction suffers from significant barriers of C-C coupling and complex reaction pathways. Due to remarkable tunability over morphology/pore architecture along with great feasibility of functionalization to modify the electronic and geometric structures, carbon materials, serving as active components, supports, and promoters, provide exciting opportunities to tune both the adsorption properties of intermediates and the local reaction environment for the CO₂ reduction, offering effective solutions to enable C-C coupling and steer C₂₊ evolution. However, general design principles remain ambiguous, causing an impediment to rational catalyst refinement and application thrusts. This review clarifies insightful design principles for advancing carbon materials. First, the current performance status and challenges are discussed and effective strategies are outlined to promote C₂₊ evolution. Further, the correlation between the composition, structure, and morphology of carbon catalysts and their catalytic behavior is elucidated to establish catalytic mechanisms and critical factors determining C₂₊ performance. Finally, future research directions and strategies are envisioned to inspire revolutionary advancements.