Synergistic Ru/CeO2 heterostructure for alkaline hydrogen oxidation with high activity and CO tolerance

The lack of highly efficient and stable electrocatalysts for anodic hydrogen oxidation reaction (HOR) has limited the large-scale industrial application of alkaline exchange membrane fuel cell. In this work, a Pt-free Ru/CeO2 heterostructure electrocatalyst with outstanding catalytic activity and stability for alkaline HOR is developed. The synthesized Ru/CeO2 with synergistic heterogeneous interface exhibits a high kinetic current density reaching 21.7 mA cm(-2) at an overportentail of 50 mV, which is nearly 11-fold higher than that of the contrastive Ru/C catalyst and almost the same as that of commercial Pt/C catalyst. Importantly, this electrocatalyst also shows high CO resistance that Pt/C catalyst lacks. Electrochemical results and spectral studies show that CeO2 not only efficiently adjusts the electronic microenvironment of Ru site to promote H-ad adsorption, but also provides the adsorption sites for OHad at a low potential. As a result, the introduced CeO2 synergistically promotes hydrogen oxidation, H2O formation and CO removing, thereby enhancing the HOR performance of Ru nanoclusters. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.