Self-Compensating Effects on the Stability of Pt/C Catalysts for Hydrogen Peroxide Oxidation Reaction in Acid

The stability of electrocatalysts in acidic solutions containing H₂O₂ is crucial for the large-scale application of innovative electrochemical devices utilizing H₂O₂ electrocatalytic reactions for energy conversion and storage. Herein, we investigate the stability of Pt/C catalysts for the H₂O₂ oxidation reaction (HPOR), examining the evolution of their structure and electrochemical properties. During stability testing, we found that Pt/C catalysts exhibit great activity retention despite a loss of electrochemical active area (ECA) caused by particle coarsening. The increase in Pt particle size is attributed to the H₂O₂-promoted formation of PtOH, followed by its electrochemical dissolution and redeposition at the HPOR potential. Remarkably, both specific activity and intrinsic kinetic activity for the HPOR increase with the Pt particle size. The enhanced intrinsic activities of larger Pt particles offset the ECA loss during long-term operation, revealing a self-compensating effect. These findings highlight Pt/C as a promising electrocatalyst for H₂O₂-related electrochemical devices.