Atomically dispersed Ru oxide catalyst with lattice oxygen participation for efficient acidic water oxidation

Summary

The development of highly efficient and stable electrocatalysts toward the acidic oxygen evolution reaction (OER) is essential for the practical application of proton-exchange membrane water electrolyzers. Although Ru oxides possess remarkable initial activity toward the acidic OER due to the kinetically favorable lattice oxygen oxidation mechanism pathway, the soluble high-valence oxygen-vacancy intermediate (∗Vo-RuO₄²⁻) may accelerate the dissolution of Ru species, leading to dramatically decreased activity and unsatisfied long-term stability. Here, we developed a robust metal-organic framework anchored strategy by stabilizing atomically isolated Ru oxide on UiO-67-bpydc with strong coordinating pyridine ligands. Theory calculations and experimental results including in situ Raman, X-ray absorption spectroscopy, and ¹⁸O-labeled differential electrochemical mass spectrometry reveal that the Ru–N bonds between Ru oxide and UiO-67-bpydc could not only accelerate the participation of lattice oxygen during the OER process but also stabilize the soluble ∗Vo-RuO₄²⁻ intermediate, which contribute to the enhanced OER performance and long-term stability of up to 115 h.