Symposium EN05: Electrodes for Chemical and Energy Conversion Technologies

Joakim Halldin Stenlid, NASA Ames Research Center 

Role of surface roughening in enhancing selectivity of copper for CO2 electroreduction 
Written by In Young Park 

Efficient and selective carbon dioxide (CO₂) reduction is critical for a sustainable carbon cycle, with copper (Cu) remaining the only metal catalyst capable of producing significant multicarbon (C₂⁺) products like ethylene and ethanol. Roughened copper surfaces—achieved through methods like sputtering or electropolishing—have shown enhanced selectivity for multicarbon products, but understanding the origin of this improvement is key to developing practical catalysts. This novel work by Joakim Halldin Stenlid and his research team models roughened copper surfaces derived from cuprous oxide using a hybrid approach combining empirical medium theory (EMT), semilocal density functional theory (DFT) using the revised Perdew-Burke-Ernzerhof (RPBE) functional, and grand canonical potential DFT. Using the alpha parameter scheme to link local structure, site stability, and adsorption energies, the study generates selectivity maps capturing trends for polycrystalline copper surfaces, identifying "sweet spots" for multicarbon selectivity. Results reveal a broad distribution of active sites on roughened surfaces, far from idealized structures, highlighting the potential of macroscopic roughness to control atomic-scale catalytic activity. Future work aims to explore the impact of intensified roughening methods on catalytic performance, advancing the design of efficient carbon dioxide reduction catalysts.