Enhancing local K⁺ adsorption by high-density cube corners for efficient electroreduction of CO₂ to C₂₊ products

Abstract

Reducing carbon dioxide (CO₂) to high value-added chemicals using renewable electricity is a promising approach to reducing CO₂ levels in the air and mitigating the greenhouse effect, which depends on high-efficiency electrocatalysts. Copper-based catalysts can be used for electroreduction of CO₂ to produce C₂₊ products with high added value, but suffer from poor stability and low selectivity. Herein, we propose a strategy to enhance the field effect by varying the cubic corner density on the surface of Cu₂O microspheres for improving the electrocatalytic performance of CO₂ reduction to C₂₊ products. Finite element method (FEM) simulation results show that the high density of cubic corners helps to enhance the local electric field, which increases the K⁺ concentration on the catalyst surface. The results of CO₂ electroreduction tests show that the FE_C₂₊ of the Cu₂O catalyst with high-density cubic corners is 71% at a partial current density of 497 mA cm^-2. Density functional theory (DFT) calculations reveal that Cu₂O (111) and Cu₂O (110) can effectively reduce the energy barrier of C-C coupling and improve the FE_C₂₊ at high K⁺ concentrations relative to Cu₂O (100). This study provides a new perspective for the design and development of efficient CO₂RR catalysts.