Gas-Diffusion Electrodes for Carbon Dioxide Reduction: A New Paradigm

Significant advances have been made in recent years discovering new electrocatalysts and developing a fundamental understanding of electrochemical CO 2 reduction processes. This field has progressed to the point that efforts can now focus on translating this knowledge toward the development of practical CO 2 electrolyzers, which have the potential to replace conventional petrochemical processes as a sustainable route to produce fuels and chemicals. In this Perspective, we take a critical look at the progress in incorporating electrochemical CO 2 reduction catalysts into practical device architectures that operate using vapor-phase CO 2 reactants, thereby overcoming intrinsic limitations of aqueous-based systems. Performance comparison is made between state-of-the-art CO 2 electrolyzers and commercial H 2 O electrolyzers—a well-established technology that provides realistic performance targets. Beyond just higher rates, vapor-fed reactors represent new paradigms for unprecedented control of local reaction conditions, and we provide a perspective on the challenges and opportunities for generating fundamental knowledge and achieving technological progress toward the development of practical CO 2 electrolyzers.