The Quasi‐Pt‐Allotrope Catalyst: Hollow PtCo@single‐Atom Pt1 on Nitrogen‐Doped Carbon toward Superior Oxygen Reduction.

Single‐atom Pt and bimetallic Pt3Co are considered the most promising oxygen reduction reaction (ORR) catalysts, with a much lower price than pure Pt. The combination of single‐atom Pt and bimetallic Pt3Co in a highly active nanomaterial, however, is challenging and vulnerable to agglomeration under realistic reaction conditions, leading to a rapid fall in the ORR. Here, a sustainable quasi‐Pt‐allotrope catalyst, composed of hollow Pt3Co (H‐PtCo) alloy cores and N‐doped carbon anchoring single atom Pt shells (Pt1N‐C), is constructed. This unique nanoarchitecture enables the inner and exterior spaces to be easily accessible, exposing an extra‐high active surface area and active sites for the penetration of both aqueous and organic electrolytes. Moreover, the novel Pt1N‐C shells not only effectively protect the H‐PtCo cores from agglomeration but also increase the efficiency of the ORR in virtue of the isolated Pt atoms. Thus, the H‐PtCo@Pt1N‐C catalyst exhibits stable ORR without any fade over a prolonged 10 000 cycle test at 0.9 V in HClO4 solution. Furthermore, this material can offer efficient and stable ORR activities in various organic electrolytes, indicating its great potential for next‐generation lithium–air batteries as well. A novel Quasi‐Pt‐allotrope, that is, hollow metallic PtCo@Pt1N‐C, has outstanding oxygen reduction reaction performance both in aqueous and organic electrolytes. The synergistic structure of Pt3Co and single Pt atoms provides more active sites and reduces the binding energy of O2. The porous carbon offers tunnels for good flow of electrolytes and protects the alloy from agglomeration. [ABSTRACT FROM AUTHOR]