Surfactant-driven interfacial engineering of copper surfaces for enhanced electrochemical CO2 reduction

• Surfactant-Driven modification lead via CTAB treatment of copper metallic surfaces significantly enhances electrochemical CO 2 reduction performance. • Faradaic efficiency increases from 40% to 71%, reflecting improved selectivity and enhanced formate production. • CTAB-modified copper surfaces exhibit sustained high efficiency, maintaining performance over a 12-hour period. • The modification lowers the onset potential, facilitating more efficient initiation of CO 2 reduction reactions. Achieving carbon neutrality necessitates innovative strategies, such as CO 2 -driven conversion technologies, to convert carbon dioxide into useful chemicals and fuels. An initiative of surfactant-driven interfacial engineering holds promises for transforming copper catalysts in electrochemical CO 2 reduction. This work demonstrates tailoring the surface contact using surfactant and its impact on reaction behaviour as a proof-of-concept. Herein we exploit a surfactant-directed interface via electrodeposition techniques with a treatment of CTAB (cetyltrimethylammonium bromide) to enhance the hydrophobicity of the copper surfaces. This modification strategy resulted in notable enhancements in electrocatalytic kinetics and a reduced onset potential, thereby facilitating more efficient initiation of CO 2 reduction reactions. However, a remarkable improvement has been observed in Faradaic efficiency (FE) which rose from 40% with unmodified copper electrodes to 71% with CTAB-modified electrodes. This enhancement represents improved selectivity for the CO 2 reduction reaction and significant improvements in formate synthesis. Furthermore, the copper surface treated with CTAB displayed outstanding stability, retaining a high level of FE over 12 h. These findings show that surfactant-driven interface engineering has the potential to revolutionise copper surfaces and improve the stability and efficiency of electrochemical CO 2 reduction technologies.