In this article, we discuss an electroless under potential deposition (UPD) method to synthesize core@shell monolayer nanoparticles in bulk quantities. In this electroless UPD method, potential is controlled and maintained in the UPD region by a redox couple. This electroless path enables the production of core@shell monolayer catalysts on any type of support, unlike the conventional UPD, where potential is controlled by an external power source which allows for the deposition only on conductive supports such as carbon. This was demonstrated by synthesizing Pt(shell)@Pd(core) nanopartricles on both conductive (Vulcan carbon) and non-conductive (alumina) supports by Cu UPD-galvanic replacement method. Core-shell structure of the Pd-Pt nanoparticles was confirmed by STEM characterization. The thickness of Pt shell in Pt@Pd nanoparticles was examined by analytical and experimental observations. Furthermore, catalytic activity of Pt@Pd/C nanoparticles, synthesized by the electroless Cu UPD-galvanic replacement method, was examined for oxygen reduction reaction.

Graphical Abstract

中文翻译：

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化学镀铜UPD可扩展生产单层壳（Pt）@核（Pd）纳米粒子用于氧还原反应

在本文中，我们讨论了无电势沉积法（UPD）来大量合成核壳型单层纳米颗粒。在该无电UPD方法中，通过氧化还原对控制并维持UPD区域中的电势。与常规的UPD不同，这种无电路径能够在任何类型的载体上生产核壳单层催化剂，而传统的UPD则通过外部电源控制电势，该外部电源仅允许沉积在导电载体如碳上。通过Cu UPD-电置换法在导电（Vulcan碳）和非导电（氧化铝）载体上合成Pt（壳）@Pd（核）纳米颗粒可以证明这一点。通过STEM表征证实了Pd-Pt纳米颗粒的核-壳结构。通过分析和实验观察检查了Pt @ Pd纳米颗粒中Pt壳的厚度。此外，研究了通过化学铜UPD-电置换法合成的Pt @ Pd / C纳米粒子的催化活性，以进行氧还原反应。

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