Distinctive Coordination Configuration and Interfacial Water Balance Induced by Anti‐Kirkendall Effect Attain Exceptional Catalytic Activity and Selectivity

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Abstract A critical challenge for the application of direct ethanol fuel cells (DEFCs) lies in the sluggish kinetics of C─C cleavage. Herein, a significant portion of Ni is retained in the interior of nitric acid etched PtFeCoNi pod‐like nanowires (PtFeCoNi‐N) with incomplete voids/cavities due to anti‐Kirkendall effect. The efficient electronic tuning toward surface Pt gives rise to the superior ethanol oxidation reaction (EOR) activity of 1.82 A mg Pt −1 and 3.21 mA cm −2 , 4.80‐fold and 5.10‐fold improved relative to Pt/C, respectively. Strikingly, after chronoamperometric test of 50 000 s and 1500 consecutive potential cycles, 86.81% and 82.42% of the initial activity of PtFeCoNi‐N are retained. Multiple spectroscopic characterizations reveal that the PtFeCoNi‐N shows excellent selectivity toward C1 pathway even above 1.0 V. The lowered Pt coordination related to less occupancy of antibonding states plays a crucial role for enhancement in activity and selectivity. The interfacial microenvironment balance between hydrogen‐bonded H 2 O and free H 2 O contributes to H 2 O dissociation for CO* oxidation. Density functional theory elucidates the origin of anti‐Kirkendall effect and the intimate electronic interaction with surface Pt that endows PtFeCoNi‐N with superior inclination toward C1 pathway. This work presents a novel catalyst design strategy of reversing the dissolution of transition metals.

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