Palladium-ceria nanocatalyst for hydrogen oxidation in alkaline media: Optimization of the Pd–CeO2 interface

The development of Pt-free catalyst for anion exchange membrane fuel cells is limited by the sluggish hydrogen oxidation reaction (HOR) at the anode. Previously, the use of CeO2 as a catalyst promoter facilitated drastic ennoblement of Pd for the HOR kinetics in base media. However, further optimization and understanding of the Pd–CeO2 interaction, surface properties, and their influence on HOR are still needed. In this work, three types of Pd–CeO2/C catalysts are synthesized by a flame-based process, where the Pd–CeO2 interface and the HOR activity are improved as compared to catalysts prepared by wet-chemistry processes. The correlation between the Pd–CeO2 interaction and the HOR activity is established through comparisons of three types of Pd–CeO2/C synthesized catalysts using electrochemical techniques and X-ray photoelectron spectroscopy.