Single atomic Ru in TiO₂ boost efficient electrocatalytic water oxidation to hydrogen peroxide

Electrocatalytic two-electron water oxidation affords a promising approach for distributed production of H₂O₂ using electricity. However, it suffers from the trade-off between the selectivity and high production rate of H₂O₂ due to the lack of suitable electrocatalysts. In this study, single atoms of Ru were controllably introduced into titanium dioxide to produce H₂O₂ through an electrocatalytic two-electron water oxidation reaction. The adsorption energy values of OH intermediates could be tuned by introducing Ru single atoms, offering superior H₂O₂ production under high current density. Notably, a Faradaic efficiency of 62.8% with an H₂O₂ production rate of 24.2 μmol min^-1 cm^-2 (>400 ppm within 10 min) was achieved at a current density of 120 mA cm^-2. Consequently, herein, the possibility of high-yield H₂O₂ production under high current density was demonstrated and the importance of regulating intermediate adsorption during electrocatalysis was evidenced.