CeO2C2 Nanoparticles with Oxygen-Enriched Vacancies In-site Self-embedded in Fe, N Co-doped Carbon Nanofibers as Efficient Oxygen Reduction Catalyst for Zn-Air Battery†

Comprehensive Summary Rational design of robust non-noble electrocatalysts with numerous oxygen vacancies and highly reactive activity for oxygen reduction reaction (ORR) towards Zn-air batteries is extremely paramount yet challenging. Herein, a novel CeO 2 C 2 nanoparticles self-embedded in Fe, N co-doped carbon nanofibers (CeO 2 C 2 @Fe-N-C) heterostructure catalyst has been prepared by the in-site dual template assisted electrospinning technique and subsequent high temperature pyrolysis strategy. Thanks to the CeO 2 C 2 with oxygen-enriched vacancies and versatile Fe-N-C with rich reactive species and high conductivity, CeO 2 C 2 @Fe-N-C catalyst exhibits outstanding catalytic performance in the ORR process, and shows excellent methanol tolerance and cycle stability. In addition, CeO 2 C 2 @Fe-N-C delivers a nearly four-electron transfer process in the process of oxygen reduction catalysis, providing a fast-electrochemical kinetic rate, which makes it an efficient air cathode for the Zn-air battery. Importantly, the Zn-air battery fabricated with CeO 2 C 2 @Fe-N-C cathode achieves superior performance including large open-circuit voltage (1.5 V) and high specific capacity (780 mAh·g –1 at 10 mA·cm –2 ) together with superior reversibility and cycling stability, outperforming commercial Pt/C catalyst. The present work introduces a new strategy to design and develop highly active non-noble catalysts and highlights the synergy from heterostructure in oxygen electrocatalysis for advanced Zn-air batteries.