Boosting CO2 electroreduction on a Zn electrode via concurrent surface reconstruction and interfacial surfactant modification

Abstract

Herein, we report an effective strategy for improving the electrocatalytic CO₂ reduction reaction (CO₂RR) performance of a Zn foil electrode via concurrent surface reconstruction and interfacial surfactant modification. The oxide-derived and CTAB-modified Zn electrode (OD-Zn-CTAB) prepared by electrochemically reducing the air-annealed Zn foil electrode in the presence of CTAB exhibits high electrocatalytic activity and selectivity for CO production with a CO partial current density (j_CO) of 8.2 mA cm⁻² and a CO faradaic efficiency (FE_CO) of 90% at −1.0 V vs. the reversible hydrogen electrode (RHE), greatly outperforming the pristine Zn foil (FE_CO = 32.0%; j_CO = 0.5 mA cm⁻²) and OD-Zn (FE_CO = 77.6%; j_CO = 5.0 mA cm⁻²) obtained by electroreduction of annealed Zn. The greatly enhanced CO₂RR performance of OD-Zn-CTAB can be attributed to the increased number of active sites originating from the surface reconstruction and the formation of a favorable CTAB-modified electrode/electrolyte (E/E) interface that can efficiently adsorb and activate CO₂ while inhibiting the competitive H₂ evolution reaction.