Intermetallic Pt-based nanoparticles have displayed excellent activity for the oxygen reduction reaction (ORR) in fuel cells. However, it remains a great challenge to synthesize highly atomically ordered Pt-based nanoparticle catalysts because the formation of an atomically ordered structure usually requires high-temperature annealing accompanied by grain sintering. Here we report the direct epitaxial growth of well-aligned, highly atomically ordered PtFe and PtFe nanoparticles (<5 nm) on single-walled carbon nanotube (SWCNT) bundles films. The long-range periodically symmetric van der Waals (vdW) interactions between SWCNT bundles and Pt-Fe nanoparticles play an important role in promoting not only the alignment ordering of inter-nanoparticles but also the atomic ordering of intra-nanoparticles. The ordered PtFe/SWCNT catalyst showed enhanced ORR catalytic performance of 2.3-fold higher mass activity and 3.1-fold higher specific activity than commercial Pt/C. Moreover, the formation of an interlocked interface and strong vdW interaction endow the Pt-Fe/SWCNT catalysts with extreme long-term stability in potential cycling and excellent anti-thermal sintering ability.

中文翻译：

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从碳纳米管束中外延生长高度原子有序的 Pt-Fe 纳米粒子作为耐用的氧还原电催化剂


金属间铂基纳米粒子在燃料电池中的氧还原反应（ORR）中表现出优异的活性。然而，合成高度原子有序的Pt基纳米粒子催化剂仍然是一个巨大的挑战，因为原子有序结构的形成通常需要高温退火并伴随晶粒烧结。在这里，我们报告了在单壁碳纳米管 (SWCNT) 束薄膜上直接外延生长排列良好、高度原子有序的 PtFe 和 PtFe 纳米粒子 (<5 nm)。 SWCNT束和Pt-Fe纳米粒子之间的长程周期性对称范德华（vdW）相互作用不仅在促进纳米粒子间的排列有序性而且在促进纳米粒子内的原子有序性方面发挥着重要作用。有序 PtFe/SWCNT 催化剂表现出增强的 ORR 催化性能，其质量活性比商业 Pt/C 高 2.3 倍，比活性高 3.1 倍。此外，互锁界面的形成和强vdW相互作用赋予Pt-Fe/SWCNT催化剂在电势循环方面具有极长的长期稳定性和优异的抗热烧结能力。