Understanding amorphous PrOx-based N-doped carbon catalyst as an efficient electrocatalyst for oxygen reduction reaction

Abstract

The development of an efficacious and easily prepared nonprecious metal electrocatalyst is crucial for the oxygen reduction reaction (ORR). This work used a dual template method to prepare the amorphous rare earth-based catalyst PrO_x-NC, and optimized the calcination temperature and proportion. The PrO_x-NC-900 catalyst has high durability and activity and exhibits superior ORR performance in alkaline electrolytes with an onset potential (E₀) of 0.96 V and a half-wave potential (E_1/2) of 0.85 V. The research results indicate that the ORR performance of rare earth oxide composite carbon catalysts can be improved by adjusting oxygen vacancies (O_v). In addition, high specific surface area, N rich defect carbon, increased oxygen vacancies, and the synergistic effect of oxygen vacancies and N-doped carbon interfacial layer play a significant part in the enhancement of ORR. The performance of the zinc air battery assembled with PrO_x-NC-900 is significantly improved, and rare earth oxides and carbon frameworks originating from metal organic frameworks (MOFs) contribute to the oxygen electrocatalyst and electron transfer rate of the zinc air battery. This catalyst provides promising information for the development of rare earth metal oxide nanostructures as potential candidate materials for ORR in alkaline media.