CO2 electroreduction in a bubble-plate electrolyzer: A new route to scale up

Abstract

CO₂ electroreduction (CO₂ER) provides a promising pathway for carbon utilization, but achieving high single-pass conversion is hindered by mass transfer limitations and the scalability constraints of conventional reactor designs. This work introduces a novel bubble-plate electrolyzer (BPE) that incorporates cobalt phthalocyanine (CoPc) catalysts immobilized on carbon paper substrates. This design creates abundant dynamic triple-phase interfaces, enhancing mass transfer and reaction kinetics. A gas-facing catalyst configuration optimizes bubble-catalyst interactions, resulting in exceptional catalytic performance and enabling scalable reactor design. A multi-layer BPE architecture achieves a remarkable single-pass CO₂ conversion of 28.74%, a substantial increase from the single-layer 6.11%, while maintaining excellent kinetic similarity and operational simplicity. Mechanistic studies reveal that a synergistic interplay between current density and CO₂ concentration governs CO₂ reduction within the BPE, where the unique gas flow configuration optimizes reactant residence time. This innovative BPE design provides a compelling strategy for practical and scalable carbon conversion technologies.