Enhancing C2 production in CO2 electroreduction using hierarchical copper–organic links: a molecular engineering approach for advanced metal–organic framework catalysts

Abstract

The application of solar and wind energy to facilitate CO₂ electrocatalytic reduction (CO₂RR) represents a transformative approach for converting intermittent renewable energy into chemical energy, thereby advancing the realisation of dual carbon goals. However, the intricate gas–electrode–electrolyte three-phase interface and the linear proportionality of multi-electron/multi-proton transfer intermediates pose substantial challenges for the CO₂RR, including low electrocatalytic activity, limited current density, poor selectivity and insufficient stability. Organic/inorganic hybrid catalysts, which integrate the benefits of heterogeneous inorganic and homogeneous molecular catalysts, offer a promising solution to this issue. Herein, a molecularly engineered metal–organic framework (MOF) system with a two-dimensional coordination network based on hierarchical copper–organic links is designed. The calcined CuBTC (CuBTC-265 °C) exhibits a large active surface area and enhanced adsorption of reaction intermediates. It achieves a faradaic efficiency (FE) of 45.2% for C₂H₄ production at −1.2 V vs. RHE, with a C₂ product FE of 65.6% and a combined C₁–C₂ product FE of 82.94%. This study provides mechanistic insights into the design of Cu catalysts for the CO₂RR.