Synergistic effect of Ru single atoms and MnO2 to boost oxygen reduction/evolution activity via strong electronic interaction

•Ru single atoms anchored on the surface of MnO2 nanorods were constructed by a facile low-temperature solid-phase reaction.•Theoretical calculation results indicate that Mn and Ru sites of Ru SAs@MnO2 act as ORR and OER active sites, respectively.•The Ru SAs@MnO2 exhibits a comparable ORR performance to commercial Pt/C, and high OER performance. Ru-based single-atomic catalysts have shown great potential application in sustainable electrochemical energy conversion/storage devices. Herein Ru single atoms anchored on the surface of MnO2 nanorods (Ru SAs@MnO2) have been successfully constructed by a facile low-temperature solid-phase reaction, which has been confirmed by X-ray adsorption spectra. The synthesized Ru SAs@MnO2 catalyst exhibits a comparable ORR performance with half-wave potential of 0.83 V and a limiting current density of 7.1 mA cm−2 to commercial Pt/C, and high OER performance with the overpotential of 320 mV at 10 mA cm−2. Theoretical calculation results indicate that Mn sites and Ru sites of Ru SAs@MnO2 act as the catalytic ORR and OER sites, respectively, and the synergistic effect between Ru SAs and MnO2 contributes to the improved catalytic performance via strong electronic interaction. When assembled zinc-air batteries, a maximum power density 230.0 mW cm−2 could be delivered at 318.5 mA cm−2.