Exceptionally active and stable RuO2 with interstitial carbon for water oxidation in acid

Summary

Oxygen evolution reaction (OER) plays a critical role in energy conversion technologies. Significant progress has been made in alkaline conditions. In contrast, it remains a challenge to develop stable OER electrocatalysts in acidic conditions. Herein, we report a new strategy to stabilize RuO₂ by introducing interstitial carbon (C-RuO₂-RuSe), where the optimized C-RuO₂-RuSe-5 exhibits a low overpotential of 212, 259, and 294 mV to reach a current density of 10, 50, and 100 mA cm⁻², respectively. More importantly, C-RuO₂-RuSe-10 has long-term stability of up to 50 h, representing one of the most stable OER electrocatalysts. X-ray absorption spectroscopy reveals that the Ru–O bonds have been elongated due to the formation of interstitial C. Theoretical calculations show that the elongated Ru–O bonds in RuO₂ enhance its stability and reduce energy barriers for OER. This work provides a new perspective for designing and constructing efficient Ru-based electrocatalysts for water splitting.