The dissolution of Pd and corrosion of carbon supports may reduce the stability of the Pt monolayer (ML) on Pd-based core catalysts, which will lead to a decrease in their electrocatalytic performances toward the oxygen reduction reaction (ORR). Herein, we report preparation of Pd(111) nanosheets (NS) onto carbon-supported WNi substrates using CO as a reducing and capping agent. Such Pd_NS/WNi layers can significantly enhance the ORR performance of a Pd_NS/WNi/C catalyst in alkaline and a Pt_ML/Pd_NS/WNi/C catalyst in acidic media. The dominating Pd(111) facets and consequently diminished low-coordination sites enhanced their electrocatalytic activity. Meanwhile, the inhibition of Pd–O formation bonds even at 1.1 V due to the presence of WNi/C substrates and additional shape-induced contraction caused by the slight Pd dissolution at the side edges resulted in the improvement in durability. Furthermore, the stability of the carbon supports was improved because of the protection from the well-covered WNi substrates.

中文翻译：

---

通过WNi基体上的Pd（111）纳米片增强Pt单层催化剂的氧还原性能

Pd的溶解和碳载体的腐蚀会降低Pd基核催化剂上Pt单层（ML）的稳定性，这将导致其对氧还原反应（ORR）的电催化性能下降。在这里，我们报告使用CO作为还原剂和封端剂，在碳负载的WNi基材上制备Pd（111）纳米片（NS）。这样的Pd _NS / WNi层可以显着增强Pd _NS / WNi / C催化剂在碱性和Pt _ML / Pd _NS中的ORR性能/ WNi / C催化剂在酸性介质中。Pd（111）占主导地位，因此减少了低配位位点，增强了其电催化活性。同时，由于存在WNi / C基板，甚至在1.1 V时，Pd-O形成键的抑制作用以及由于侧边缘的少量Pd溶解引起的额外的形状诱导的收缩，都提高了耐久性。此外，由于保护了覆盖良好的WNi基材，提高了碳载体的稳定性。