Highly Selective Hydrogen Peroxide Production Using an AgPd-Based Electrocatalyst with Ultralow Pd Loading

Efficient electrocatalysts are key to advancing H₂O₂ production via the oxygen reduction reaction (ORR), but challenges like high material costs and low efficiency hinder progress. Based on this, this study focuses on the development and evaluation of a bimetallic AgPd/C electrocatalyst with ultralow Pd loading (0.2 wt %) designed for the selective ORR, specifically targeting the production of H₂O₂. The catalyst was synthesized using a galvanic replacement method, combining Ag and Pd in a random atomic arrangement on Vulcan XC-72 carbon support to optimize the dispersion and conductivity of active sites. Electrochemical analyses revealed that the AgPd/C electrocatalyst exhibited remarkable selectivity for H₂O₂, maintaining selectivity above 75% within a defined potential range. This selectivity significantly outperformed the Vulcan XC-72 catalyst, which showed a notable decline over the same range. Furthermore, the AgPd/C catalyst displayed superior resistance to methanol crossover compared to commercial Pt/C electrocatalysts, demonstrating its potential for stable and efficient operation in methanol-fueled applications. The combination of Ag and Pd enhanced the selectivity for the two-electron ORR mechanism and reduced energy requirements for initiating electroreduction, making it a promising candidate for applications requiring high H₂O₂ selectivity, such as green chemical processes. Our findings suggest that the selective 2e^- ORR behavior arises from the surficial structure achieved via the galvanic replacement synthesis with ultralow Pd content.