Enhanced selectivity and activity for electrocatalytic reduction of CO2 to CO on an anodized Zn/carbon/Ag electrode

Abstract

We constructed a composite electrode by depositing a C/Ag mixture containing a tiny amount of 20 nm Ag NPs (∼0.5 wt%) on anodized Zn (AZ) metal. The AZ/C/Ag electrode exhibits greatly enhanced CO selectivity (∼86%) and activity (∼7.3 mA cm⁻²) on comparison with the GCE/C/Ag electrode (∼24% and ∼2.3 mA cm⁻²). The experimental results show that the enhanced CO₂ reduction performance of the AZ/C/Ag electrode is attributed to the synergistic effect of AZ, C and Ag. Density functional theory calculations indicate that the enhanced CO selectivity may originate from the enhanced stabilization of CO₂ and COOH* on the AZ/C/Ag electrode surface. This electrode also shows great mass activity and stability for CO₂ reduction. Our work provides a new and simple way to fabricate efficient catalysts with high selectivity, activity and stability for electrocatalytic CO₂ reduction.