Electronically modulated d-band centers of MOF-derived carbon-supported Ru/HfO2 for oxygen reduction and aqueous/flexible zinc-air batteries

Porous nitrogen-doped carbon embedded with Ru/HfO2 particles (Ru/HfO2-NC) was constructed by the ZIF-assisted approach as a high-efficient ORR electrocatalyst for zinc-air batteries. We observed abundant oxygen vacancies in the HfO2 component and strong charge interactions between Ru and HfO2 species. The designed catalyst shows excellent ORR performance and has potential applications in aqueous/flexible zinc-air batteries.