A Structure-Defined Cu(I) Dual-Atom Catalyst with a Cu₂N₆ Motif in a Metal-Organic Framework for CO Electroreduction

The electroreduction of carbon monoxide (CO) provides a sustainable pathway to valuable multi-carbon (C₂₊) products, contributing to carbon neutrality. Enhancing coupling efficiency and selectivity for C₂₊ formation hinges on precise control of the spatial arrangement of catalytic sites where CO molecules adsorb. Here, we introduce a structurally well-defined Cu(I) dual-atom catalyst (DAC) embedded in a metal-organic framework (MOF) that is synthesized via a thermal transformation. Single-crystal X-ray diffraction (SCD) reveals Cu₂N₆ motifs with a Cu-Cu distance of 3.6 Å, stabilized by tetrazolate within a 2D layer, ensuring CO accessibility and efficient coupling. The catalyst achieves a Faradaic efficiency (FE) of 72% for C₂₊ products at a partial current density of -430 mA cm^-2, and a maximum C₂₊ FE of 86% at a total current density of -200 mA cm^-2. In situ spectroscopy and density functional theory (DFT) calculations reveal that the paired Cu nodes stabilize key C₂ intermediates via distinct binding configurations, underpinning the system's exceptional performance.