CeO2 quantum dots embedded in 3D hierarchical porous foliaceous N- doped carbon as an efficient oxygen reduction electrocatalyst for metal- air battery

The development of large-scale and highly efficiency catalysts towards oxygen reduction reaction (ORR) is of great significance for the wide application of metal-air batteries. In this work, we propose a self-sacrifice template method combined with in-situ composite technique to fabricate a novel configuration of CeO2 quantum dots embedded in hierarchical porous foliaceous N-doped carbon with both mesopores and micropores. The prepared catalyst exhibits prominent ORR electrocatalytic performance with higher half-wave potential, lower Tafel slope, and enhanced durability comparing with the commercial Pt/C catalyst. Furthermore, the Zn-air and Al-air batteries employing the prepared electrocatalysts in cathodes exhibit superior discharge performance with high open circuit voltages of 1.51 V and 1.76 V, and peak power densities of 204 and 458 mW cm(-2), respectively, compared to most reported metal-air batteries. The greatly enhanced electrocatalytic performance can be ascribed to the abundant oxygen vacancies, improved redox property of Ce3+/Ce4+ as well as the three-dimensional hierarchical porous structure. This work provides a valuable chance to develop scalable quantum dot level composite catalysts in metal-air batteries. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, a novel catalyst with CeO2 quantum dots embedded in porous N-doped carbon was successfully fabricated using a self-sacrifice template method combined with in-situ composite technique, showing excellent ORR electrocatalytic performance. The prepared catalyst exhibited superior performance compared to commercial Pt/C catalyst and showed better performance in zinc-air and aluminum-air batteries.