Nanoarchitectonics for modulation on the electronic structure of ultrafine PtRuFe nanowires as robust methanol electrooxidation catalysts

The widespread adoption of Pt-based electrocatalysts in the anode side of direct methanol fuel cell (DMFC) faces challenges stemming from their limited activity, stability, and high cost. Herein, ultrafine PtRu_xFe_y trimetallic nanowires (PtRu_xFe_y NWs) with a diameter of approximately 1.25 nm were synthesized for the electrocatalytic methanol oxidation reaction (MOR). The structure-activity relationship between the electronic structure of PtRu_xFe_y NWs and their electrocatalytic performance was established by meticulously controlling the addition of Ru(acac)₃ and Fe(Ac)₂. Under optimal conditions, PtRu_0.25Fe_0.14 NWs displayed remarkable MOR performance, boasting the mass activity (1332.3 mA mg_Pt⁻¹) and specific activity (1.0 mA cm⁻²), a 4.0-fold and 1.8-fold enhancement over that of the commercial catalysts. Additionally, after a chronoamperometry test, PtRu_0.25Fe_0.14 NWs demonstrated a current density 8.3 times higher than that of Pt/C under the same test conditions. The excellent MOR performance of PtRu_xFe_y NWs can be attributed to their one-dimensional and ultrafine structure advantages, the electronic effects of Ru/Fe on Pt, and the bifunctional capabilities. Our research may lead to a simple and controllable strategy that combines various approaches to enhance the performance of Pt-based electrocatalysts in the anode of DMFC.