Low-Pt Octahedral PtCuCo Nanoalloys: "One Stone, Four Birds" for Oxygen Reduction and Methanol Oxidation Reactions

To find a low-Pt electrocatalyst that is functionally integrated and superior to the state-of-the-art single-Pt electrocatalyst is expectedly a challenge. We have in this study found that the reactivity of the oxygen reduction reaction (ORR) and the methanol oxidation reaction (MOR), in both acidic and alkaline electrolytes (viz., four half-cell reactions), can be modified and greatly enhanced by the electronic and/or synergistic effects of a low-Pt octahedral PtCuCo alloy. For the ORR, the mass activity (MA) of Pt_0.23Cu_0.64Co_0.13/C in an acidic or alkaline electrolyte was 14.3 or 10.7 times that of the commercial Pt/C. For the MOR, the MA of Pt_0.23Cu_0.64Co_0.13/C in an acidic or alkaline electrolyte was 7.2 or 3.4 times that of the commercial Pt/C. In addition, Pt_0.23Cu_0.64Co_0.13/C exhibited an increased durability and CO tolerance, as compared with the commercial Pt/C. Density functional theory calculations demonstrated that the PtCuCo(111) surface can effectively optimize the O* binding energy. This work has successfully shown an example of how both acidic and alkaline ORR and MOR activities can be significantly synchronously enhanced.