Optimized Hydroxyl Generation and Replenishment by Structural Defect‐Mediated Fishbone‐Like High‐Entropy Alloy Nanowires Boost Ethanol Oxidation Catalysis
Аннотация
ABSTRACT A grand challenge for ethanol oxidation reaction (EOR) catalysts lies in the well trade‐off between catalytic activity, C1 pathway selectivity, and long‐term stability. Herein, a novel type of PtFeCoIrRh fishbone‐like high‐entropy alloy nanowires (FHEANWs) with miscibility gaps between metal components was fabricated. The multiple structural defects associated with lattice distortion characteristic of HEAs endow PtFeCoIrRh FHEANWs with the exceptional activity of 2.85 A mg Pt −1 /1.77 A mg Noble metal −1 and 4.48 mA cm −2 , 7.50/4.66 and 6.69 times more efficient than that of Pt/C, respectively. After long 50 000 s chronoampermetric and 2000 consecutive cycling stability tests, PtFeCoIrRh FHEANWs retain 68.42% and 76.39% of the initial activity. Also, X‐ray adsorption spectroscopy elucidates the structural stability based on the variation in coordination configuration due to elemental migration within the FHEANWs. The attenuated total reflection‐surface enhanced infrared absorption spectroscopy, coupled with theoretical calculations, reveals that the elemental synergism and dynamic balance between hydrogen‐bonded H 2 O and isolated free H 2 O at the solid‐liquid interface facilitate OH* generation and timely replenishment and the more efficient C1 pathway (58.54% selectivity at 1.0 V) while preventing H 2 O passivation. This work paves a new path for designing HEA anisotropic nanostructures featuring structural defects toward superb catalytic activity, stability, and selectivity.
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