Co_3O_4 nanoparticles assembled on polypyrrole/graphene oxide for electrochemical reduction of oxygen in alkaline media

作     者：任素贞 郭亚男 马少博 毛庆 吴丹丹 杨莹 景洪宇 宋雪旦 郝策 Suzhen Ren;Yanan Guo;Shaobo Ma;Qing Mao;Dandan Wu;Ying Yang;Hongyu Jing;Xuedan Song;Ce Hao

作者机构：大连理工大学化学学院辽宁大连116024 大连理工大学化工学院辽宁大连116024 

出 版 物：《Chinese Journal of Catalysis》 (催化学报（英文）)

年 卷 期：2017年第38卷第7期

页      面：1281-1290页

核心收录：

学科分类：0808[工学-电气工程] 081705[工学-工业催化] 08[工学] 0817[工学-化学工程与技术] 

基　　金：supported by the National Natural Science Foundation of China(21373042)~~ 

主　　题：Non-precious metal electrocatalyst Co3O4 Polypyrrole Graphene Oxygen reduction reaction Proton-exchange membrane fuel cell 

摘      要：The development of highly efficient catalysts for cathodes remains an important objective of fuel cell research. Here, we report Co3O4 nanoparticles assembled on a polypyrrole/graphene oxide electrocatalyst （Co3O4/Ppy/GO） as an efficient catalyst for the oxygen reduction reaction （ORR） in alkaline media. The catalyst was prepared via the hydrothermal reaction of Co2＋ ions with Ppy-modified GO. The GO, Ppy/GO, and Co3O4/Ppy/GO were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The incorporation of Ppy into GO nanosheets resulted in the formation of a nitrogen-modified GO po-rous structure, which acted as an efficient electron-transport network for the ORR. With further anchoring of Co3O4 on Ppy/GO, the as-prepared Co3O4/Ppy/GO exhibited excellent ORR activity and followed a four-electron route mechanism for the ORR in alkaline solution. An onset potential of -0.10 V vs. a saturated calomel electrode and a diffusion limiting current density of 2.30 mA/cm^2 were achieved for the Co3O4/Ppy/GO catalyst heated at 800 ℃; these values are comparable to those for noble-metal-based Pt/C catalysts. Our work demonstrates that Co3O4/Ppy/GO is highly active for the ORR. Notably, the Ppy coupling effects between Co3O4 and GO provide a new route for the preparation of efficient non-precious electrocatalysts with hierarchical porous structures for fuel cell applications.