Construction of a Novel Cascade Electrolysis‐Heterocatalysis System by Using Zeolite‐Encaged Ultrasmall Palladium Catalysts for H₂O₂ Generation

Abstract In situ generation of hydrogen peroxide (H₂O₂) has attracted extensive attention, especially in water treatment. However, traditional anthraquinones can only produce high‐concentration H₂O₂ and its transportation and storage are not convenient and dangerous. Herein, an in situ and on‐demand strategy to produce H₂O₂ by using a cascade water electrolysis together with a heterocatalysis system is provided. Beginning with water, H_2, and O₂ can be generated via electrolysis and then react with each other to produce H₂O₂ immediately on efficient zeolite‐encaged ultrasmall Pd catalysts. Significantly, the H₂O₂ generation rate in the optimized cascade system reaches up to 0.85 mol L⁻¹ h⁻¹ g_Pd⁻¹, overcoming most of the state‐of‐the‐art catalysts in previous literature. The confinement effect of zeolites is not only beneficial to the formation of highly dispersed metal species, promoting the H₂O₂ generation, but also inhibits the H₂O₂ decomposition, enhancing the production yield of H₂O₂. In addition, the effect of electrolytes, sizes of Pd species, as well as zeolite acidity are also systematically studied. This work provides a new avenue for H₂O₂ generation via a highly efficient cascade electrolysis‐heterocatalysis system by using zeolite‐supported metal catalysts. The high catalytic efficiency and green process for H₂O₂ generation make it very promising for further practical applications.