Nitrogen-Doped\nIntermetallic PtCo Catalyst with Multilayered\nPt-Skin Surfaces for the Oxygen Reduction Reaction

Catalysts with a platinum-rich shell and intermetallic\ncore are\nconsidered to be one of the most promising catalysts for the oxygen\nreduction reaction (ORR) in fuel cells. However, too thin of a platinum-rich\nshell makes the core–shell structure easy to lose. Therefore,\nthe development of the core–shell structure with an appropriate\nthickness of platinum-rich shell and intermetallic core remains a\nhuge challenge in the field of fuel cells. In this paper, PtCoN-1000/C\ncatalyst with about 1 nm thick platinum-rich shell shows significantly\nenhanced ORR activity and stability in acidic electrolyte, which is\nsuperior to L1<sub>0</sub>-PtCo/C and commercial Pt/C catalysts. The\nspecific power at 0.8 V and mass activity at 0.9 V are 5.60 W mg<sub>Pt</sub><sup>–1</sup> and 0.74 A mg<sub>Pt</sub><sup>–1</sup>, respectively. It suggests that the tensile strain and moderately\nthickened platinum-rich shell led by nitrogen doping can greatly improve\nthe performance of the catalyst.