Ultrathin Pt nanostructures exposing controlled crystal facets are highly desirable for their superior activity and cost-effectiveness in the electrocatalytic oxygen reduction reaction (ORR), and they are conventionally synthesized by epitaxial growth of Pt on a limited range of templates, such as Pd nanocrystals, resulting in a high cost and less structural diversity of the ultrathin Pt nanostructures. To solve this problem, we demonstrate that ultrathin Pt nanostructures can be synthesized by templating conveniently available Ag nanocrystals without involving galvanic replacement, which enables a much-reduced cost and controllable new morphologies, such as ultrathin Pt nanoplates that expose the {111} facets. The resulting ultrathin Pt nanoplates are ∼1–2 nm in thickness, which show an ∼22-fold increase in specific activity (5.3 mA cm⁻²), an ∼9.5-fold increase in mass activity (1.62 A mg⁻¹) and significantly enhanced catalytic stability in the ORR, compared with the commercial Pt/C catalyst. We believe this strategy opens a door to a highly extendable family of ultrathin noble metal nanostructures, thus promising excellent activity and stability in a broad range of catalytic applications.

中文翻译：

---

合成超薄铂纳米板以增强氧还原活性†

暴露受控晶面的超薄 Pt 纳米结构因其在电催化氧还原反应 (ORR) 中的优异活性和成本效益而非常受欢迎，并且它们通常是通过在有限范围的模板上外延生长 Pt 来合成的，例如 Pd 纳米晶体，导致超薄 Pt 纳米结构的成本高且结构多样性少。为了解决这个问题，我们证明，可以通过模板化方便获得的银纳米晶体来合成超薄铂纳米结构，而不涉及电取代，这可以大大降低成本和可控的新形态，例如暴露{111}面的超薄铂纳米板。由此产生的超薄 Pt 纳米板厚度约为 1-2 nm，比活性增加了 22 倍（5.3 mA cm ^-2），质量活性增加了 9.5 倍（1.62 A mg ^-1），与商用 Pt/C 催化剂相比，ORR 中的催化稳定性显着增强。我们相信，这一策略为高度可扩展的超薄贵金属纳米结构家族打开了大门，从而有望在广泛的催化应用中表现出优异的活性和稳定性。