Cu‐W Synergistic Doping in Porous Multiphase Pd Metallene for Efficient C1 Product Formation in Ethanol Electrooxidation

ABSTRACT Direct ethanol fuel cells are promising clean energy devices, but the difficulty in cleaving the C─C bond of ethanol leads to low C1 pathway selectivity (typically ∼10%) and incomplete energy conversion. To address this challenge, we synthesized a porous multiphase Pd‐based metallene nanocatalyst co‐doped with oxygen‐philic Cu and W. Temperature was identified as the key factor regulating the crystal structure: low temperatures yielded amorphous phases, high temperatures produced crystalline phases, and intermediate temperatures formed the desired crystalline/amorphous mixed multiphase structure. This multiphase structure provided abundant active sites. The optimal PdCuW metallene exhibited exceptional performance for ethanol electrooxidation: a record‐high C1 pathway selectivity of 72.6% (1.6 times that of undoped Pd metallene and 10.2 times that of commercial Pd/C), a mass activity of 4301.6 mA/mg _Pd (4.7 times that of commercial Pd/C), and superior stability (only 7.3% activity decay vs. 67.9% for commercial Pd/C). Mechanistic studies (In situ ATR‐FTIR, DFT calculations) revealed that synergistic Cu‐W doping reduced the C─C bond cleavage energy barrier, enhanced OH ^* adsorption, and weakened the poisoning effect of intermediate CO ^* . The work offers a rational design strategy for high‐selectivity electrocatalysts, advancing ethanol's full energy utilization and holding broad implications for Pd‐based catalyst systems in energy conversion technologies.