Effects of heat treatment on the structure, morphology and electrocatalytic activity of cobalt hydroxide electrocatalyst

• Published in: International journal of hydrogen energy 2010-03, Vol.35 (5), p.1872-1878
• Main Authors: Qin, Haiying, Lao, Shaojiang, Liu, Zixuan, Zhu, Jingke, Li, Zhoupeng
• Format: Article
• Language: English
• Subjects: Applied sciences; Cobalt; Cobalt hydroxide; Direct borohydride fuel cell; Electrocatalysts; Electrocatalytic activity; Electron transfer; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Heat treatment; Hydroxides; Morphology; Oxygen reduction reaction; Particulate composites; Precursors
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2010.01.014

In this study, effects of heat treatment on structure, morphology and electrocatalytic activity of polypyrrole-modified carbon-supported Co(OH) 2 (Co(OH) 2-PPY-C) are investigated. The Co(OH) 2-PPY-C is heated under N 2 atmosphere at temperature ranging from 400 to 800 °C. CoO will be formed when heating the precursor to 400 °C. With elevating heat treatment temperature to 600 °C, metallic Co and Co 3O 4 are formed. Spheroidal particles composed of CoO, Co 3O 4 and metallic Co will be formed when heating the Co(OH) 2-PPY-C to 800 °C. It is found that the composite of CoO, Co 3O 4 and metallic Co with platelet shape is beneficial to oxygen reduction reaction (ORR). The electron transfer number of this catalyst towards ORR in alkaline medium is determined to be 4.