Strong Electronic Interactions of the Abundant Cu/Ce Interfaces Stabilized Cu2O for Efficient CO2 Electroreduction to C2+ Products under Large Current Density

Abstract

Copper-based nanocatalysts, represented by Cu₂O nanocubes, are crucial for electrocatalytic CO₂ conversion to C₂₊ products but face significant stability challenges. Structural reconstruction from Cu dissolution and reduction under negative potentials undermines their long-term stability. Herein, a novel Cu₂O@CeO_x core-shell nanocatalyst is introduced, featuring a Cu₂O nanocube core encapsulated by an amorphous CeO_x shell. Due to the facilitated electron transfer of abundant Cu/Ce interfaces, the CeO_x shell layer simultaneously prevents the agglomeration and maintains the oxidation state of Cu₂O nanocubes, bringing in significantly improved stability. Unlike conventional coating layers, the defective CeO_x shell uniquely avoids obstructing mass transfer while effectively promoting the activation of CO₂ and optimizing the electronic structure of Cu. The Cu₂O@CeO_x nanocatalyst delivers a remarkable C₂₊ Faradaic efficiency exceeding 80% at 300 mA cm⁻² under a low applied potential of −0.98 V, with exceptional durability lasting over 50 h, compared to just 2 h for Cu₂O alone. This work presents an effective strategy to enhance catalyst stability without sacrificing activity, advancing the design of durable catalysts for electrocatalytic applications.