Interface‐Defect‐Rich In‐Mo Codoped Pd Metallene for Enhanced C1 Selectivity During Electrocatalytic Ethanol Oxidation

ABSTRACT Direct ethanol fuel cells (DEFCs) are promising clean energy devices, but their efficiency is limited by the low C‐C bond cleavage efficiency of Pd‐based catalysts. Herein, we synthesized In‐Mo codoped Pd metallene with rich interface defects via a simple wet‐chemical method, which consists of face‐centered cubic, intermetallic and amorphous phases. The catalyst's structure and ethanol electrooxidation reaction (EOR) performance was systematically characterized, and the mechanism was revealed by in situ ATR‐FTIR, HPLC and DFT calculations. Results showed that the optimal PdInMo metallene exhibited a C1 pathway selectivity of 73.68%, which was 12.02 time that of commercial Pd/C. Its mass activity and specific activity were 4273.8 mA mg Pd −1 and 8.36 mA cm −2 , 2.38 and 1.34 times higher than those of undoped Pd metallene (1795.9 mA mg Pd −1 and 6.25 mA cm −2 ), 6.85 and 3.83 times higher than those of commercial Pd/C (624.2 mA mg Pd −1 and 2.18 mA cm −2 ), respectively, with excellent cycling stability (75.10% activity retention). The enhanced performance was attributed to the synergistic effect of In─Mo codoping and rich interface defects: strengthened OH* adsorption, weakened CO* adsorption, and reduced C─C bond cleavage energy barrier. This study provides a novel strategy for designing high‐selectivity and high‐activity Pd‐based catalysts for EOR.