Electrocatalytic Activity and Stability of Platinum Nanoparticles Supported on Carbon–Molybdenum Oxides for the Oxygen Reduction Reaction

Abstract

Abstract The degradation of Pt‐based electrocatalysts used in proton‐exchange membrane fuel cell (PEMFC) cathodes is one of the main issues restricting the widespread application of PEMFCs as energy converters. This work aims to contribute to the improvement of the stability of platinum nanoparticles (Pt NPs) by modifying the support to which they are anchored. Thus, syntheses of catalyst supports based on molybdenum oxides and carbon are carried out, followed by impregnation of the supports with Pt NPs. The Pt/MoO 3 –C catalyst shows the highest specific activity in the oxygen reduction reaction (ORR), and this must be because of synergistic metal–support effects. Regarding the electrochemical stability of the materials, it is observed that, in principle, none of the Mo oxides decrease the extent of Pt degradation. However, after comparing the specific ORR activities before and after electrochemical ageing, it is concluded that Pt/MoO 2 *–C is a more stable material compared to Pt/C and Pt/MoO 3 –C.