Regulating the Oxygen Evolution Mechanism through In Situ Reconstruction of Ru-Modified Manganese Oxybromide

Prof. Philip C.Y. Chow's group recently published an article in ACS Energy Letters. Water electrolysis is a promising technology for converting renewable energy into green hydrogen fuel. However, its widespread adoption is hindered by the lack of oxygen evolution reaction (OER) catalysts that combine high activity and excellent durability in acidic conditions.

This study addresses this issue by developing a novel Ru single-atom (Ru-SA) catalyst supported on manganese oxybromide (Mn7.5O10Br3, MOB) nanoparticles (Ru-MOB) with high acidic OER activity and superior stability. It is found that a reversible bias-induced surface reconstruction on Ru-MOB towards Ru-SA modified γ-MnO2, which serves as a passivation layer during OER. Furthermore, in situ/operando experiments and first-principles calculations provide evidence that Ru-MOB drives OER predominantly via the adsorbate evolution mechanism (AEM) with significantly suppressed lattice oxygen participation, owing to the synergistic electronic interactions between the reconstructed support and the Ru-SA. This mechanism regulation allows the optimized Ru-MOB to overcome the performance-stability tradeoff in acidic OER, realizing a low overpotential of 208.3 mV at a current density of 10 mA cm−2 and stable operations (>1400 h at 10 mA cm-2 and >200 h at 100 mA cm-2) with negligible degradation

The research was led by Ci Lin (HKU Mech. Eng. PhD student). It was accepted by ACS Energy Letters on April 30, 2025.

Article in ACS Energy Letters

Link: https://pubs.acs.org/doi/10.1021/acsenergylett.5c00957

C. Lin, T.-Y. Chen, T. Zhou, Y. Wu, C. K. T. Wun, W. Chen, H. Chen, V. Tung, Z. Guo, T. W. B. Lo, L. Cai, Y. Deng, P. C. Y. Chow, Regulating the Oxygen Evolution Mechanism through In Situ Reconstruction of Ru-Modified Manganese Oxybromide. ACS Energy Lett., 2641–2649 (2025).