Nitrogen-doped carbon layer coated CeNiOx as electrocatalyst for oxygen reduction reaction

It is highly desirable but challenging to develop and construct a high activity, good stability and cost-effective catalyst system applied for oxygen reduction reaction (ORR). In this study, a series of CeNiOx@CN-n catalysts (carbonized polypyrrole coated CeNio(x)) is prepared by an in-situ polymerization method. The effects of bimetal component and nitrogen-doped carbon layer thickness in a nitrogendoped carbon layer-oxide composite system are explored for ORR. It shows that the atomic ratio of Ce: Ni =1:1 is the optimal ratio, and the ratio of polypyrrole: oxide = 1: 1 is the optimal layer thickness. As the best-performing electrocatalyst, CeNiOx@CN-4 follows a 4e(-) pathway for ORR. Moreover, it exhibits good electrocatalytic activity and stability. Especially, its ability of anti-methanol poisoning is stronger than that of Pt/C catalyst. Predictably, this nitrogen-doped carbon layer-oxide composite system would open up a potential way to design more efficient electrocatalysts. (C) 2018 Elsevier B.V. All rights reserved.