Construction of a Novel Cascade Electrolysis-Heterocatalysis System by Using Zeolite-Encaged Ultrasmall Palladium Catalysts for H O Generation.

In situ generation of hydrogen peroxide (H O ) has attracted extensive attention, especially in water treatment. However, traditional anthraquinones can only produce high-concentration H O and its transportation and storage are not convenient and dangerous. Herein, an in situ and on-demand strategy to produce H O by using a cascade water electrolysis together with a heterocatalysis system is provided. Beginning with water, H and O can be generated via electrolysis and then react with each other to produce H O immediately on efficient zeolite-encaged ultrasmall Pd catalysts. Significantly, the H O generation rate in the optimized cascade system reaches up to 0.85 mol L h g , 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 H O generation, but also inhibits the H O decomposition, enhancing the production yield of H O . 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 H O generation via a highly efficient cascade electrolysis-heterocatalysis system by using zeolite-supported metal catalysts. The high catalytic efficiency and green process for H O generation make it very promising for further practical applications.