Bimetallic ZnCo zeolitic imidazolate framework/ polypyrrole-polyaniline derived Co/N-doped carbon for oxygen reduction reaction

摘要

Non-noble-metal based materials with high activity for oxygen reduction reaction (ORR) are urgently required to substitute Pt-based materials. Herein, metallic Co/N-doped carbon electrocatalysts were synthesized via a facile pyrolysis method of bimetal ZIF(ZnCo)/polypyrrole-polyaniline (ppy-pani) precursors. The evaporation of Zn and the introduced ppy-pani can lead to the porous structure and effectively hinder the aggregation of Co species, which results in the small nanoparticles uniformly distributed on carbon matrices. A high ECSA and a high content of Co species are obtained after the introduction of ppy-pani, thus resulting in the abundant Co2+ species to enhance ORR. Therefore, the optimized ZIF/ppy-pani-750 exhibits a high E-1/2(similar to 0.86 V) and a low Tafel slope (similar to 43.6 mV decb(-1)). (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.