Operational strategies of pulsed electrolysis to enhance multi-carbon product formation in electrocatalytic CO 2 reduction

• Published in: EES catalysis Vol. 2; no. 4; pp. 997 - 1005
• Main Authors: Ito, Takashi, Raj, Jithu, Zhang, Tianyu, Roy, Soumyabrata, Wu, Jingjie
• Format: Journal Article
• Language: English
• Published: 04.07.2024
• ISSN: 2753-801X; 2753-801X
• DOI: 10.1039/D4EY00039K

The electrocatalytic reduction of CO 2 offers a promising avenue for converting anthropogenic CO 2 into valuable chemical and fuel feedstocks. Copper (Cu) catalysts have shown potential in this regard, yet challenges persist in achieving high selectivity for multi-carbon (C 2+ ) products. Pulsed electrolysis, employing alternating anodic and cathodic potentials ( E a / E c ) or two different cathodic potentials ( E c1 / E c2 ), presents a promising approach to modulate activity and selectivity. In this study, we investigate the influence of catalyst morphology and operational strategies on C 2+ product formation using Cu nanoparticles (NPs) and CuO nanowires (NWs) in flow cells. In E a / E c mode, commercial Cu NPs show negligible promotion of C 2+ selectivity while CuO NWs demonstrate enhanced C 2+ selectivity attributed to facile oxidation/redox cycling and grain boundary formation. In contrast, E c1 / E c2 pulsed electrolysis promotes C 2+ yield across various catalyst morphologies by enhancing CO 2 accumulation, pH effect, and supplemental CO utilization. We further extend our investigation to membrane electrode assembly cells, highlighting the potential for scalability and commercialization. Our findings underscore the importance of catalyst morphology and operational strategies in optimizing C 2+ product formation pulsed electrolysis, laying the groundwork for future advancements in CO 2 electroreduction technologies.