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High-Performance Nitrogen-Doped Intermetallic PtNi Catalyst for the Oxygen Reduction Reaction
ACS Catalysis ( IF 11.3 ) Pub Date : 2020-08-25 , DOI: 10.1021/acscatal.0c03036
Xueru Zhao 1, 2 , Cong Xi 2 , Rui Zhang 3 , Liang Song 1 , Chenyu Wang 4 , Jacob S. Spendelow 4 , Anatoly I. Frenkel 1, 5 , Jing Yang 2 , Huolin L. Xin 3 , Kotaro Sasaki 1
Affiliation  

PtM (M = transition metals) nanomaterials have been recognized as promising catalysts for the oxygen reduction reaction (ORR) in fuel cells, with a much higher performance than pure Pt. However, the insufficient durability issue of PtM is often raised because of the fast dissolution of M in acid, impeding their commercialization. Herein, we report on a Ketjenblack (KB)-supported, nitrogen (N)-doped intermetallic PtNiN (Int-PtNiN/KB) catalyst that exhibits remarkably enhanced ORR activity and stability in an acidic electrolyte, superior to those of disordered PtNi/KB, disordered PtNiN/KB, and commercial Pt/C. The experimental results show that Int-PtNiN/KB has a distinctive ordering structure of alternating Ni4–N and Pt planes; we attribute the origin of the superior stability of this catalyst to the combined effect of the Ni4–N formation and the unique intermetallic structure, which effectively precludes Ni dissolution from the core. The density functional theory calculations suggest that the tensile strain introduced by the formation of an intermetallic phase and N-doping optimizes the binding of oxygenated species on the Pt surface and enable highly efficient electron transfer, leading to the enhanced ORR performance. This study offers an appropriate route for further enhancing both the activity and durability of PtM catalysts through a facile synthesis method by annealing in an NH3 gas under appropriate conditions.

中文翻译:

高性能氮掺杂金属间PtNi催化剂的氧还原反应

PtM(M =过渡金属)纳米材料已被公认为是燃料电池中氧还原反应(ORR)的有前途的催化剂,其性能远高于纯Pt。但是,由于M在酸中的快速溶解,常常导致PtM耐久性不足的问题,从而阻碍了其商业化。在本文中,我们报道了一种由科琴黑(KB)负载的,掺杂氮(N)的金属间PtNiN(Int-PtNiN / KB)催化剂,该催化剂在酸性电解质中的ORR活性和稳定性显着高于无序PtNi / KB。 ,无序的PtNiN / KB和商用Pt / C。实验结果表明,Int-PtNiN / KB具有交替的Ni 4独特的有序结构。–N和Pt平面;我们将这种催化剂的优异稳定性归因于Ni 4 -N形成和独特的金属间结构的结合作用,这有效地阻止了Ni从芯中溶解。密度泛函理论计算表明,通过金属间相的形成和N掺杂引入的拉伸应变优化了Pt表面上的氧化物种的结合,并实现了高效的电子转移,从而提高了ORR性能。这项研究为通过在适当条件下在NH 3气体中进行退火的简便合成方法,进一步提高PtM催化剂的活性和耐久性提供了一条适当的途径。
更新日期:2020-09-20
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