Mn <sub>0.75</sub> Ru <sub>0.25</sub> O <sub>2</sub> with Low Ru Concentration for Active and Durable Acidic Oxygen Evolution
Ruthenium has emerged as a promising alternative to iridium in water-splitting anodes. However, it becomes overoxidized and dissolves at industry-relevant working conditions. To enhance the activity and stability of electrocatalysts for oxygen evolution reaction, an isostructural rutile MnRu oxide with low Ru concentration (Mn<sub>0.75</sub>Ru<sub>0.25</sub>O<sub>2</sub>) is synthesized and an asymmetric Mn-O-Ru dual-site active center is developed. It exhibits 154 mV overpotential at 10 mA cm<sup>-2</sup> and can operate stably at 200 mA cm<sup>-2</sup> for 670 h with a degradation rate of 29 uV/h<sup>-1</sup>. A proton exchange membrane water electrolyzer achieves stable operation at 1 A cm<sup>-2</sup> for 700 h with a degradation rate of 53 uV h<sup>-1</sup>. Structural analysis and isotopic labeling correlate the asymmetric nature of the Mn-O-Ru dual-site active center, which facilitates the oxygen evolution reaction along the radical coupling pathway, with the stabilization of the cations and the lattice oxygen in isostructural rutile Mn<sub>0.75</sub>Ru<sub>0.25</sub>O<sub>2</sub>.
Authors
- Pengfei Ou (ORCID: https://orcid.org/0000-0002-3630-0385)
- Yuxin Chang (ORCID: https://orcid.org/0000-0003-0091-8316)
- Daojin Zhou (ORCID: https://orcid.org/0000-0002-8466-7413)
- Jialun Tang
Institutions
- National University of Singapore (SG)
- University of Toronto (CA)
- Beijing University of Chemical Technology (CN)
Publication Details
- Journal
- Small
- Published
- 2025-02-16
- DOI
- https://doi.org/10.1002/smll.202412265
- Citations
- 2
- Primary Topic
- Electrocatalysts for Energy Conversion
- Type
- article
- Field-Weighted Citation Impact
- 0.73
Funders
- National University of Singapore
- National Natural Science Foundation of China