The electroreduction of carbon monoxide (CO) provides a sustainable pathway to valuable multi-carbon (C<sub>2+</sub>) products, contributing to carbon neutrality. Enhancing coupling efficiency and selectivity for C<sub>2+</sub> 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 Cu<sub>2</sub>N<sub>6</sub> 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 C<sub>2+</sub> products at a partial current density of -430 mA cm<sup>-2</sup>, and a maximum C<sub>2+</sub> FE of 86% at a total current density of -200 mA cm<sup>-2</sup>. In situ spectroscopy and density functional theory (DFT) calculations reveal that the paired Cu nodes stabilize key C<sub>2</sub> intermediates via distinct binding configurations, underpinning the system's exceptional performance.