Asymmetric Cu−N1O3 Sites Coupling Atop‐type and Bridge‐type Adsorbed *C1 for Electrocatalytic CO2‐to‐C2 Conversion

Abstract 2D functional porous frameworks offer a platform for studying the structure–activity relationships during electrocatalytic CO 2 reduction reaction (CO 2 RR). Yet challenges still exist to breakthrough key limitations on site configuration (typical M−O 4 or M−N 4 units) and product selectivity (common CO 2 ‐to‐CO conversion). Herein, a novel 2D metal–organic framework (MOF) with planar asymmetric N/O mixed coordinated Cu−N 1 O 3 unit is constructed, labeled as BIT‐119. When applied to CO 2 RR, BIT‐119 could reach a CO 2 ‐to‐C 2 conversion with C 2 partial current density ranging from 36.9 to 165.0 mA cm −2 in flow cell. Compared to the typical symmetric Cu−O 4 units, asymmetric Cu−N 1 O 3 units lead to the re‐distribution of local electron structure, regulating the adsorption strength of several key adsorbates and the following catalytic selectivity. From experimental and theoretical analyses, Cu−N 1 O 3 sites could simultaneously couple the atop‐type (on Cu site) and bridge‐type (on Cu−N site) adsorption of *C 1 species to reach the CO 2 ‐to‐C 2 conversion. This work broadens the feasible C−C coupling mechanism on 2D functional porous frameworks.