Sorbents in CO ₂ RR: When Integration Outpaces Understanding

The integration of CO 2 sorbents into electrochemical CO 2 reduction (CO 2 RR) systems is often proposed as a strategy to enhance the local CO 2 availability and improve the process efficiency. However, a critical analysis of recent literature reveals that many implementations fall short of their theoretical potential. This Perspective highlights the conceptual and experimental pitfalls in current sorbent-augmented CO 2 RR research, showing that performance gains are frequently limited by system-level constraints rather than sorbent properties. By benchmarking reported partial current densities against diffusion-limited theoretical maxima, we demonstrate that sorbent integration is rarely the true performance-limiting factor. We argue that future work must prioritize rigorous benchmarking, clearer mechanistic hypotheses, and system-aware design to unlock the full potential of integrated CO 2 capture and conversion.