CO Adsorption Energy Match at Dual Sites Drives C–C Coupling Activity in Rare Earth–Cu CO 2 Reduction Catalysts

ABSTRACT Due to their unique f orbitals and electrons, rare earth (RE)‐doped copper‐based catalysts show promise for producing specific multi‐carbon products via CO 2 reduction. However, how different types of Re elements affect the key C–C coupling steps remains unclear, and as a result, RE–Cu dual‐site catalysts often face challenges due to the lack of definitive design guidelines. To address this issue, we introduce a descriptor, the adsorption energy matching degree of *CO intermediates between RE and Cu sites, which enables computational screening of high‐performance RE‐Cu alloy catalysts. Electrochemical tests show that Cu doped with 0.16% Yb achieves remarkable stability (50 h at >1.5 A cm −2 ) and selectivity (65% Faradaic efficiency for C 2 H 4 ) in a membrane electrode assembly (MEA). In situ characterization reveals that Yb atoms substituting Cu participate in C–C coupling and promote efficient C 2 H 4 production. This work establishes a design principle for highly efficient RE‐doped Cu electrocatalysts.