Pt-based nanoframe catalysts have been explored extensively due to their superior activity toward the oxygen reduction reaction (ORR). Herein, we report the synthesis of Pt–Ni multiframes, which exhibit the unique structure of tightly fused multiple nanoframes and reinforced by an embedded dendrite. Rapid reduction and deposition of Ni atoms on Pt–Ni nanodendrites induce the alloying/dealloying of Pt and Ni in the overall nanostructures. After chemical etching of Ni, the newly formed dendrite-embedded Pt–Ni multiframes show an electrochemically active surface area (ECSA) of 73.4 m² g_Pt^–1 and a mass ORR activity of 1.51 A mg_Pt^–1 at 0.93 V, which is 30-fold higher than that of the state-of-the-art Pt/C catalyst. We suggest that high ECSA and ORR performances of dendrite-embedded Pt–Ni multiframes/C can be attributed to the porous nanostructure and numerous active sites exposed on surface grain boundaries and high-indexed facets.

中文翻译：

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树枝状嵌入的铂镍多框架是高活性和持久性的氧还原反应电催化剂

基于Pt的纳米框架催化剂由于其对氧还原反应（ORR）的优异活性而被广泛地研究。在本文中，我们报告了P​​t-Ni多重骨架的合成，该骨架表现出紧密融合的多个纳米骨架的独特结构，并由嵌入的树枝状晶体增强。Ni原子在Pt-Ni纳米树枝晶上的快速还原和沉积会在整个纳米结构中引起Pt和Ni的合金化/脱合金。对镍进行化学蚀刻后，新形成的嵌入枝晶的Pt-Ni复合框架显示出73.4 m ² g _Pt ^–1的电化学活性表面积（ECSA）和1.51 A mg _Pt ^–1的质量ORR活性电压为0.93 V，比最新的Pt / C催化剂高30倍。我们认为，枝晶包埋的Pt-Ni复帧/ C的高ECSA和ORR性能可以归因于多孔纳米结构以及暴露在表面晶界和高折射率刻面上的大量活性位。