Pt-Skin Coated PtNi Alloy in Carbon Nanoshells for Enhanced Hydrogen Evolution Activity and Durability

Hydrogen, as an environmentally sustainable energy carrier, offers substantial potential for addressing the global energy crisis. The development of highly efficient catalysts to accelerate the hydrogen evolution reaction (HER) is critical for the realization of electrochemical hydrogen production via water splitting. Herein, a novel heterogeneous catalyst consisting of PtNi nanoalloys with Pt-enriched surfaces is obtained, which are uniformly distributed within nitrogen-doped hollow carbon nanoshells derived from a complex of Ni-EDTA (ethylene diamine tetraacetate). Remarkably, the fabricated NE-PtNiNC catalyst demonstrates exceptional HER performance, exhibiting an ultra-low overpotential of 3 mV at 10 mA cm^-2 and 6.8-fold higher mass activity compared to the commercial Pt/C catalyst, positioning it as one of the most advanced catalysts to date. Additionally, it shows outstanding stability over 200 h and exhibits promising potential for practical deployment in two-electrode water electrolysis systems. Theoretical analyses further reveal that the Pt-skin@PtNi structure, with its lowest d-band center, fosters a more pronounced overlap of the 5d electron cloud at the surface Pt sites. This interaction results in increased electron density on the Pt skin, facilitating water dissociation and significantly enhancing the intrinsic HER activity and durability.