Chen, M., Tan, S. X., Cheng, S., Chen, Y.-Y., Hsu, Y.-H., Hung, S.-F., Zhang, L., & Gao, J. (2025). Revisiting the ruthenium oxide-based water oxidation catalysts in acidic media: From amorphous to crystalline. Nano Energy, 137, 110800. https://doi.org/10.1016/j.nanoen.2025.110800
Abstract:
Ruthenium oxides (RuO2) have been widely used as benchmark electrocatalysts for the water oxidation reaction (2H2O → O2 + 4H+ + 4e–). However, the catalytic activity and stability of different RuO2 electrocatalysts, such as amorphous, crystalline, and hydrated, vary significantly. In this work, different types of RuO2 were selected as model catalysts to study the structure-performance correlations, including amorphous ruthenium oxide hydrate and rutile-phase ruthenium oxides with different degrees of crystallinity and particle sizes. Cyclic voltammetry was used to study the redox behavior of ruthenium catalysts and estimate the adsorption energy of oxygen reaction intermediates (*OH and *O) under OER conditions. Moreover, hydrogen peroxide (H2O2) as a probing molecule was added to the electrolyte, and the redox of H2O2 was applied to in situ estimate the adsorption energy or interaction of *OOH intermediate on ruthenium catalysts. In situ electrochemical attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) test was conducted to monitor the adsorption of H2O on the catalyst surface. In situ electrochemical-quartz crystal microbalance was used to monitor the dissolving process of the RuO2 catalysts under reaction conditions. In-situ Raman experiments suggest that the rutile RuO2 with high crystallinity is stable during OER until the potential increases above ~1.6 V. This work provides not only a rigorous benchmark but also new insights into structure-performance relationships of various RuO2 catalysts for the water oxidation reaction.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
This research / project is supported by the Agency for Science, Technology and Research (A*STAR) - Career Development Fund
Grant Reference no. : C210812029
This research / project is supported by the Agency for Science, Technology and Research (A*STAR) - Central Research Fund
Grant Reference no. : SC22/22-11571U