Defect‐Anchored Iridium Single Atoms on Palladium Metallenes for Synergistically Enhanced Ethanol Oxidation Reaction

The development of highly efficient electrocatalysts for the ethanol oxidation reaction (EOR) is critical to the commercialization of direct ethanol fuel cells, which represent a promising clean energy technology. 2D palladium metallenes (Pd MLs) have recently emerged as attractive electrocatalytic materials with the potential to replace conventional Pt‐based catalysts, owing to their exceptionally high surface‐to‐volume ratio. However, the practical application of Pd MLs requires the construction of efficient active sites and the mitigation of stability issues associated with their defective structures. In this study, a defect‐site activation strategy is proposed involving the anchoring of single iridium (Ir) atoms onto the high‐strain defect regions of ultrathin Pd MLs, which significantly enhances their EOR performance. The optimized catalyst, Ir 0.59 /Pd ML, featuring atomically dispersed Ir, achieves a remarkable mass activity of 1085.45 mA mg −1 toward EOR—≈ 12.8 times higher than that of pristine Pd MLs. Detailed mechanistic studies indicate that the enhancement arises from the formation of synergistic PdIr sites within the defect regions. These sites concurrently improve both EOR activity and poison tolerance through electronic modulation. This work demonstrates the potential of atomic‐level engineering of intrinsic defects in metallene materials for the rational design of advanced 2D electrocatalysts.