A Self-Healing Platinum Catalyst for Methanol Oxidation Reaction

Self-healing catalysts are crucial for achieving the catalytic stability of the electrochemical reactions. However, designing self-healing structures is essential for optimal catalysts without relying on external interventions, but it remains extremely challenging. Here a self-healing platinum catalyst composed of oxygen vacancy (V_O) and active oxygen (GDY/V_O-PtO_<i>x</i> <i>Cc</i>) is designed to realize different methanol oxidation routes and high-performance alkaline methanol oxidation reactions (MOR). The resulting catalyst displays excellent mass activity of 8.8 A mg_Pt^-1 for MOR, 1 order of magnitude higher than the commercial Pt/C. The catalyst also demonstrates robust durability with no current density loss even after 300 h at a high current density of 150 mA cm^-2. In situ X-ray absorption spectroscopy reveals a reconstruction in the active structure of Pt sites from its hydrated state on a charged electrode. In situ Raman and in situ FTIR measurements on the catalyst to track the critical intermediates and unveil specific active sites to identify a CO-poisoning-free reaction route under operating conditions. In situ differential electrochemical mass spectrometry (DEMS) results coupled with theoretical calculations reveal that the catalyst provides active oxygen for methanol electrooxidation and produces an oxygen vacancy, and clearly showing the self-healing of active oxygen through OH* filling and deprotonation on the oxygen vacancy. These findings show the pivotal role of self-healing catalysts for achieving high activity and stability during the electrochemical MOR.