SnO2/CeO2 nanoparticle-decorated mesoporous ZSM-5 as bifunctional electrocatalyst for HOR and ORR

Abstract Developing highly efficient noble metal-free electrocatalysts for hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) in alkaline exchange membrane fuel cells (AEMFCs) is of great importance for the large-scale applications, which, however, still remains a great challenge. Here we present the synthesis of SnO2 and CeO2 nanoparticle-decorated mesoporous ZSM-5 (denoted as SnCe-ZSM) via electrostatic interaction, which, surprisingly, not only exhibits excellent catalytic activity towards HOR, but also largely enhance ORR performance. The strong electronic interaction between SnO2 and CeO2 nanoparticles synergistically leads to the electron-enrichment on SnO2 and oxygen vacancy accumulation on CeO2, which respectively enable the hydrogen and oxygen adsorption/activation concurrently, finally resulting in the significant enhancements of the electrocatalytic activity towards both HOR and ORR. Additionally, the SnCe-ZSM based zinc-air battery exhibits a remarkably high power density of 98 mW/cm2 and excellent stability during discharging/charging cyclic tests for 60 h. The SnCe-ZSM electrocatalyst provides a significant paradigm for designing bifunctional composite catalysts for applications in clean energy devices.