Vitalizing fuel cells with vitamins: pyrolyzed vitamin B12 as a non-precious catalyst for enhanced oxygen reduction reaction of polymer electrolyte fuel cells

• Published in: Energy & environmental science 2012-01, Vol.5 (1), p.5305-5314
• Main Authors: Chang, Sun-Tang, Wang, Chen-Hao, Du, He-Yun, Hsu, Hsin-Cheng, Kang, Chih-Ming, Chen, Chia-Chun, Wu, Jeffrey CS, Yen, Shi-Chern, Huang, Wen-Fei, Chen, Li-Chyong, Lin, M C, Chen, Kuei-Hsien
• Format: Article
• Language: English
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/C1EE01962G

The limited natural abundance and high cost of Pt has been a major barrier in its applications for hydrogen or methanol fuel cells. In this work, based on the pyrolyzed corrin structure of vitamin B12 (py-B12/C), it is reported to produce superior catalytic activity in the oxygen reduction reaction (ORR) with an electron transfer number of 3.90, which is very close to the ideal case of 4. The H sub(2)-O sub(2) fuel cell using py-B12/C provides a maximum power density of 370 mW cm super(-2) and a current density of 0.720 A cm super(-2) at 0.5 V at 70 degree C. Calculations based on density functional theory suggests that the corrin complex with a low-symmetric structure offers a much preferable path for the ORR, which is not applicable to the porphyrin with a high-symmetric structure. The long-term stability and high ORR activity of py-B12/C make it a viable candidate as a Pt-substitute in the ORR.