Advanced non-precious electrocatalyst of the mixed valence CoO x nanocrystals supported on N-doped carbon nanocages for oxygen reduction

Taking advantage of the nitrogen (N)-participation and large surface area of N-doped carbon nanocages (NCNCs), the CoO x nanocrystals are conveniently immobilized onto the NCNCs with high dispersion. The CoO x /NCNCs hybrid exists in the mixed valence with predominant CoO over Co 3 O 4 and demonstrates superb oxygen reduction reaction activity and stability remaining ~94% current density even after operation over 100 h. These results suggest a promising strategy to develop advanced electrocatalysts with the novel NCNCs or even beyond.