Synergistic Combination Inspired by the Steaming of Buns of Ce “Flour” and Zn “Baking Soda” Punches up the Oxygen Reduction

Ce-based single-atomic catalysts (SACs) are highly promising as the oxygen reduction reaction (ORR) catalysts due to the unique 4f orbital, whereas the modulating the coordination environment of single-atomic Ce sites remains challenging using simple strategies for enhancing the ORR performance. Inspired by the process of bun steaming, a composite catalyst comprising CeO₂ nanoparticles and single-atomic Ce sites within nitrogen-doped carbon matrix (CeO₂/CeZn SACs@NC) is successfully prepared by utilizing cerium salt as the primary material of flour and zinc salts as the leavening agent. X-ray absorption spectroscopy confirms that the induces the transformation from Ce─O coordination (Ce-O₅) to Ce─N coordination (Ce-N₅), which is verified to reduce reaction energy barriers of the hydrogenation of ^*OH as the rate-determining step during the ORR process from the theoretical calculation results. Notably, the optimal CeO₂/CeZn SACs@NC achieves a remarkable ORR performance with half-wave potential of 0.85 V in 0.1 m KOH and excellent Zn-air battery performance with the specific capacity of 806 mAh g_Zn ^-1 at 10 mA cm^-2, as well as remarkable long-term stability.