Highly Dispersive Cerium Atoms on Carbon Nanowires as Oxygen Reduction Reaction Electrocatalysts for Zn-Air Batteries

Highly efficient noble-metal-free electrocatalysts for oxygen reduction reaction (ORR) are essential to reduce the costs of fuel cells and metal-air batteries. Herein, a single-atom Ce-NC catalyst, constructed of atomically dispersed Ce anchored on Ndoped porous carbon nanowires, is proposed to boost the ORR. This catalyst has a high Ce content of 8.55 wt % and a high activity with ORR half-wave potentials of 0.88 V in alkaline media and 0.75 V in acidic electrolytes, which are comparable to widely studied Fe-N-C catalysts. A Zn-air battery based on this material shows excellent performance and durability. Density functional theory calculations reveal that atomically dispersed Ce with adsorbed hydroxyl species (OH) can significantly reduce the energy barrier of the rate-determining step resulting in an improved ORR activity.

Automated summary

This study introduces a single-atom Ce-NC catalyst, which boosts the activity of oxygen reduction reaction by anchoring atomically dispersed cerium on Ndoped porous carbon nanowires. The catalyst exhibits high activity with ORR half-wave potentials comparable to Fe-N-C catalysts, and shows excellent performance and durability in a zinc-air battery. Density functional theory calculations demonstrate that atomically dispersed cerium can significantly reduce the energy barrier of the rate-determining step, leading to improved ORR activity.