Reconstructed anti-poisoning surface for enhanced electrochemical CO2 reduction on Cu-incorporated ZnO

Zn-based materials are regarded as a family of promising electrocatalysts for electrochemical CO2 reduction reaction (e-CO2RR), especially for the CO2-to-CO conversion. However, their electrocatalytic performances should be improved and the conversion mechanism needs to be further studied. In this work, we fabricate Cuincorporated ZnO (Cu25Zn-A) on Zn plate for e-CO2RR catalyst by a facile annealing method. We find that Cu25Zn-A achieves a high CO Faraday efficiency > 90% with a CO yield rate of 0.49 mmol cm-2 h-1. The improved catalytic activity on Cu25Zn-A is mainly attributed to the Cu steps on the reconstructed surface in the reaction: (1) that weakens the OH-/CO32- adsorption, leading to the anti-poisoning surface by preventing the formation of Zn hydroxide/carbonates; and (2) that enhances the adsorption/activation of reactants and stabilizes the intermediates. Additionally, the density of defects in Zn oxide is increased by the Cu-incorporation, resulting in improved deoxygenation step. Our findings may provide insightful understanding on the mechanism and guide the design of novel electrocatalyst for effective CO2 reduction.

Automated summary

In this work, Cu-incorporated ZnO electrocatalyst (Cu25Zn-A) was synthesized on a Zn plate for electrochemical CO2 reduction reaction (e-CO2RR). The Cu25Zn-A exhibited a high CO Faraday efficiency (>90%) and a CO yield rate of 0.49 mmol cm-2 h-1. The enhanced catalytic activity of Cu25Zn-A was attributed to the presence of Cu steps on the reconstructed surface, which weakened the adsorption of OH-/CO32- and enhanced the adsorption/activation of reactants and stabilization of intermediates. Furthermore, Cu incorporation increased the density of defects in Zn oxide, resulting in improved deoxygenation step. These findings provide valuable insights into the mechanism of CO2 reduction and can guide the design of novel electrocatalysts.