Tuning the surface strain and atom arrangement to control the surface chemistry process is one of efficient strategies to enhance the electrocatalytic performance of nanomaterials. This research introduces an ordered Pt₃Ni₂/C intermetallic nanoparticle as a new type of the Pt-Ni system for the ORR, which is rarely reported at present. Besides, it focuses on the phase conversion of Pt₃Ni₂/C nanocatalysts from a disordered phase to an ordered phase. X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements confirm the formation of ordered face-centered cubic (fcc) type Pt₃Ni₂/C nanocatalysts with homogeneous particle distribution and average crystallite size of 6.4 nm. The ordered fcc-Pt₃Ni₂/C exhibits improved electrocatalytic activities toward the oxygen reduction reaction (ORR) in 0.1 M HClO₄ and 0.1 M KOH electrolyte when compared with Pt₃Ni₂/C disordered alloy. Besides, the robust ordered fcc-Pt₃Ni₂/C showed a smaller activity loss after durability tests in alkaline medium than acid electrolyte. The improved ORR activity and stability could be ascribed to the surface atom arrangement and reasonable surface strain originated from the ordered structure of Pt₃Ni₂/C nanoparticles relative to the disordered Pt₃Ni₂/C alloy, forcefully demonstrating that the Pt₃Ni₂/C intermetallic compound may act as highly efficient ORR electrocatalysts in energy conversion process.

调节表面应变和原子排列以控制表面化学过程是增强纳米材料电催化性能的有效策略之一。这项研究引入了有序的Pt ₃ Ni ₂ / C金属间纳米颗粒作为一种新型的ORR Pt-Ni体系，目前很少报道。此外，它着重于Pt ₃ Ni ₂ / C纳米催化剂从无序相到有序相的相转化。X射线衍射（XRD）和透射电子显微镜（TEM）测量证实形成有序的面心立方（fcc）Pt ₃ Ni _2型/ C纳米催化剂，具有均匀的颗粒分布和6.4 nm的平均微晶尺寸。与无序的Pt ₃ Ni ₂ / C合金相比，有序的fcc-Pt ₃ Ni ₂ / C对0.1 M HClO ₄和0.1 M KOH电解质中的氧还原反应（ORR）表现出改善的电催化活性。此外，在碱性介质中经耐久性测试后，坚固的有序fcc-Pt ₃ Ni ₂ / C与酸性电解质相比，显示出较小的活​​性损失。改善的ORR活性和稳定性可以归因于表面原子排列和合理的表面应变源自Pt ₃ Ni ₂的有序结构/ C纳米粒子相对于无序的Pt ₃ Ni ₂ / C合金，有力地证明了Pt ₃ Ni ₂ / C金属间化合物可以在能量转换过程中充当高效的ORR电催化剂。