Dealloying of Nitrogen-Introduced Pt–Co Alloy Nanoparticles: Preferential Core–Shell Formation with Enhanced Activity for Oxygen Reduction Reaction

[Image: see text] Voltammetric dealloying is a typical method to synthesize Pt-shell/less-noble metal (M) alloy core nanoparticles (NPs) toward the oxygen reduction reaction (ORR). The pristine nanostructures of the Pt–M alloy NPs should determine the ORR activity of the dealloyed NPs. In this study, we investigated the voltammetric dealloying behavior of the Pt–Co and nitrogen-introduced Pt–Co alloy NPs generated by synchronous arc-plasma deposition of Pt and Co. The results showed that the dealloying behavior is sensitive to cobalt nitride in the pristine NPs, leading to the preferential generation of a Pt-rich shell/Pt–Co alloy core architecture having enhanced ORR activity.