Coordination environment of Ru clusters with in-situ generated metastable symmetry-breaking centers for seawater electrolysis

Seawater electrolysis offers hope for renewable production of green hydrogen. However, its hydrogen evolution reaction (HER) is quite difficulty due to electrode corrosion and undesirable side reactions. More importantly, it is still a big challenge to regulate charge distribution of Ru clusters at atomic level for maximizing the activity. Herein, theory calculations unveil that, substituting partial Ru atoms with atomically dispersedly nonstoichiometric CdySex drives in-situ generation of metastable symmetry-breaking Ru cluster surfaces (Ru/CdySex) and more atom vacancies, which regulates the coordination environment of Ru atoms and results in optimized Ru−H bond and more channels for H migration. As expected, Ru/Cd0.02Se4 requires overpotentials as low as 4.2 and 6.3 mV at 10 mA cm−2, and has 8.1 and 9.6 times higher turnover frequency (TOF) than Ru/Sex in alkali and alkaline seawater, respectively, superior to Pt/C and most other catalysts reported so far. Also, it shows very impressive stability over 50 h. This discovery elaborates the activity origin via symmetry breaking and provides deep cognition for hydrogen product from seawater electrolysis.