Metal-Organic Framework-Derived Partially Oxidized Cu Electrocatalysts for Efficient CO2 Reduction Reaction Toward C2+ Products

Abstract

Cu-based metal-organic frameworks (Cu-MOFs) electrocatalysts are promising for CO2 reduction reactions (CO2RR) to produce valuable C2+ products. However, designing suitable active sites in Cu-MOFs remains challenging due to their inherent structural instability during CO2RR. Here we propose a synergistic strategy through thermal annealing and electrochemical-activation process for in-situ reconstruction of the pre-designed Cu-MOFs to produce abundant partially oxidized Cu (Cuδ+) active species. The optimized MOF-derived Cuδ+ electrocatalyst demonstrates a highly selective production of C2+ products, with the Faradaic Efficiency (FE) of 78 ± 2% and a partial current density of −46 mA cm−2 at −1.06 VRHE in a standard H-type cell. Our findings reveal that the optimized Cuδ+-rich surface remains stable during electrolysis and enhances surface charge transfer, leading to an increase in the concentration of *CO intermediates, thereby highly selectively producing C2+ compounds. This study advances the controllable formation of MOF-derived Cuδ+-rich surfaces and strengthens the understanding of their catalytic role in CO2RR for C2+ products.