Cu-W Synergistic Doping in Porous Multiphase Pd Metallene for Efficient C1 Product Formation in Ethanol...

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.