Network-like metallic alloys of solid nanoparticles have been frequently reported as promising electrocatalysts for fuel cells. The three-dimensional structure of such networks is rich in pores in the form of voids between nanoparticles, which collectively expose a large surface area for catalytic activity. Herein, we present a novel solution to this problem using a precursor comprising a flocculent core-shell [email protected]i to produce PtNi network catalysts with nanoparticle intraporosity after carefully controlled electrochemical dealloying. Physical characterization shows a hierarchical level of nanoporosity (intrapores within nanoparticles and pores between them) evolves during the controlled electrochemical dealloying, and that a Pt-rich surface also forms after 22 cycles of Ni leaching. In ORR cycling, the PtNi networks gain 4-fold activity in both j_ECSA and j_mass over a state of the art Pt/C electrocatalyst, and also significantly exceed previously reported PtNi networks. In ORR degradation tests, the PtNi networks also proved stable, dropping by 30.4% and 62.6% in j_ECSA and j_mass respectively. The enhanced performance of the catalyst is evident, and we also propose that the presented synthesis procedure can be generally applied to developing other metallic networks.

固体纳米颗粒的网络状金属合金经常被报道为有前途的燃料电池电催化剂。这样的网络的三维结构以纳米颗粒之间的空隙的形式富含孔，这些孔共同暴露出大的表面积以用于催化活性。本文中，我们提出了一种使用包含絮状核-壳的前驱体来解决该问题的新方法，该前驱体经过精心控制的电化学脱合金处理后可生产具有纳米颗粒内孔性的PtNi网络催化剂。物理表征表明，在受控的电化学脱合金过程中，纳米级多孔性（纳米颗粒内的孔和它们之间的孔）逐渐发展，并且在22次Ni浸出循环后也形成了富含Pt的表面。在ORR骑行中，Ĵ _ECSA和Ĵ_质量优于现有技术的Pt / C电的状态，并且也显著超过先前报道的PtNi的网络。在ORR降解测试中，PtNi网络也被证明是稳定的，其j _ECSA和j_质量分别下降了30.4％和62.6％。催化剂性能的提高是显而易见的，并且我们还提出，提出的合成程序可以普遍应用于开发其他金属网络。