Cu-Containing Metal-Organic Framework Electrocatalyst for Efficient Production of C₂₊ Compounds via CO₂ Reduction Reaction

The electrochemical reduction of CO 2 (CO 2 RR) is a promising strategy to yield valuable carbon-containing products and mitigate current environmental and energy issues. Cu-based MOF electrocatalysts have great potential for the selectivity of C 2+ products due to their unique property. However, the rational design of active sites in Cu-based MOFs needs to be further studied. In this work, we propose a strategy to evolve abundant partially oxidized Cu species by applying a negative potential prior to CO 2 RR on Cu-MOFs, which results in high faradaic efficiency of 78% and partial current density of −46 mA cm −2 at −0.95 V RHE towards multi-carbon products. The electrochemical activation of Cu-MOFs can lead to the shift of superficial chemical state from Cu 2+ to Cu + . Interestingly, the conversion rate is varied by different thermal annealing times on the pre-catalysts. Thereby, the relative concentration of Cu + species can be quantitatively compared before and after activation to reveal the dependence on those FE C2+ . The insights gained from this study can provide valuable guidance for the design and development of efficient Cu-MOF catalysts for the production of C 2+ products.