Platinum-group metals have an irreplaceable role in electro-catalyzing oxygen reduction reaction (ORR) process due to the affinity of oxygen and oxygenated intermediate. However, large overpotential and poor long-term durability prohibit their utilization in the scalable industrial application. Owing to their inherent scarcity, substantial improvements in the electrocatalytic performance (both selectivity and stability) of the catalysts are urgently necessary. Herein, a synergistic hybrid PtPd-Al₂O₃ catalyst is developed for high-selective and long-term stable hydrogen peroxide (H₂O₂) electroproduction. Synchrotron radiation characterizations are carried to clarify the synergistic effect in the catalyst. The incorporation of Pd with Pt induces a valence band restructuring and reconstructs the coordination environment of the nanoparticles. For H₂O₂ electrosynthesis through the 2e^- ORR, these electronic and structural modifications resulted in optimal adsorption energies of reaction intermediates. Therefore, the synergy hybrid of Pt and Pd not only enhance electrocatalytic activity and selectivity (96%) but also create a new coordination structure in the catalyst, increasing its long-term durability. This study introduces a new paradigm for the development of high-performance H₂O₂ electrocatalyst by demonstrating the synergistic dual function of Pd as electron promoter and structure stabilizer.

Two-dimensional transition metal hydroxides with abundant reserves and low prices have played an indispensable role in energy catalytic applications. Recent reports indicated that the incorporation of Fe species into Co-based catalysts can synergistically enhance oxygen evolution reaction (OER) activity. Constructing a heterointerface on the surface of Co-based catalysts can provide a platform to investigate the role of heterointerface in reaction kinetics. Herein, we constructed a Fe-O-Co heterointerface without electronic effect by depositing FeO_x clusters on the oxygen vacancies of CoOOH surface. FeO_x/CoOOH exhibited excellent OER intrinsic activity, which can deliver the turnover frequency (TOF) of 4.56 s⁻¹ at the overpotentials of 300 mV and the Tafel slope of 33 mV·dec⁻¹. In-situ electrochemical impedance spectroscopy (EIS) and density functional theory (DFT) calculations demonstrated that the synergistic effect between Fe sites and Co sites confined at the Fe-O-Co heterointerface accelerated the charge transfer during OER and optimized the adsorption of oxygen intermediates, consequently enhancing OER.