Dimensionality‐Driven Interfacial Electronic Coupling in Carbon‐Supported Gd‐CuO Catalysts for Selective CO 2 Electroreduction to Ethylene

Abstract

Copper‐based catalysts are promising for electrochemical CO 2 reduction toward value‐added chemicals, yet their performance is largely limited by the lack of precise control over catalytic interfaces and reaction intermediates. Here, we demonstrate carbon‐support dimensionality as a key structural descriptor for regulating Cu‐based CO 2 electroreduction interfaces. A series of carbon supports with different dimensionalities were constructed as model platforms to reveal how support geometry controls the interfacial properties of Gd‐modified CuO catalysts. The results show that carbon dimensionality dictates Cu─O coordination, oxygen‐vacancy stabilization, and intermediate evolution, with the two‐dimensional carbon architecture generating the most favorable catalytic interface. Consequently, in a conventional H‐type cell, it achieves a peak C 2 H 4 Faradaic efficiency (FE C2H4 ) of 36.14% at −1.2 V vs. RHE. In a flow cell, overcoming mass‐transport constraints, the FE C2H4 surges to 52.06% with a high C 2 H 4 current density of 105 mA cm −2 and continuous operational durability over 30 h. In situ spectroscopy and theoretical calculations reveal that the two‐dimensional interface promotes charge redistribution, stabilizes *CO intermediates, and lowers the energetic barrier for *CO‐*CO coupling toward C 2 H 4 formation. This work establishes a dimension–defect–intermediate relationship, highlighting carbon‐support dimensionality as an overlooked design parameter for programming Cu‐based catalytic interfaces beyond conventional dopant engineering.