Dynamic Surface Reconstruction of Amphoteric Metal (Zn, Al) Doped Cu₂O for Efficient Electrochemical CO₂ Reduction to C₂₊ Products

Abstract

The recognition of the surface reconstruction of the catalysts during electrochemical CO₂ reduction (CO2RR) is essential for exploring and comprehending active sites. Although the superior performance of Cu-Zn bimetallic sites toward multicarbon C₂₊ products has been established, the dynamic surface reconstruction has not been fully understood. Herein, Zn-doped Cu₂ O nano-octahedrons are used to investigate the effect of the dynamic stability by the leaching and redeposition on CO2RR. Correlative characterizations confirm the Zn leaching from Zn-doped Cu₂ O, which is redeposited at the surface of the catalysts, leading to dynamic stability and abundant Cu-Zn bimetallic sites at the surface. The reconstructed Zn-doped Cu₂ O catalysts achieve a high Faradaic efficiency (FE) of C₂₊ products (77% at -1.1 V versus reversible hydrogen electrode (RHE)). Additionally, similar dynamic stability is also discovered in Al-doped Cu₂ O for CO2RR, proving its universality in amphoteric metal-doped catalysts. Mechanism analyses reveal that the OHC-CHO pathway can be the C-C coupling processes on bare Cu₂ O and Zn-doped Cu₂ O, and the introduction of Zn to Cu can efficiently lower the energy barrier for CO2RR to C₂ H₄ . This research provides profound insight into unraveling surface dynamic reconstruction of amphoteric metal-containing electrocatalysts and can guide rational design of the high-performance electrocatalysts for CO2RR.