Zigzag carbon as efficient and stable oxygen reduction electrocatalyst for proton exchange membrane fuel cells

• DOI: 10.1038/s41467-018-06279-x
• Publication Date: 2018-09-13T13:16:25Z
• Authors: Longfei Xue; Yongcheng Li; Xiaofang Liu; Qingtao Liu; Jiaxiang Shang; Huiping Duan; Liming Dai; Jianglan Shui
• Keywords: Science; Q; 01 natural sciences; 7. Clean energy; Article; 0104 chemical sciences

AbstractNon-precious-metal or metal-free catalysts with stability are desirable but challenging for proton exchange membrane fuel cells. Here we partially unzip a multiwall carbon nanotube to synthesize zigzag-edged graphene nanoribbons with a carbon nanotube backbone for electrocatalysis of oxygen reduction in proton exchange membrane fuel cells. Zigzag carbon exhibits a peak areal power density of 0.161 W cm−2 and a peak mass power density of 520 W g−1, superior to most non-precious-metal electrocatalysts. Notably, the stability of zigzag carbon is improved in comparison with a representative iron-nitrogen-carbon catalyst in a fuel cell with hydrogen/oxygen gases at 0.5 V. Density functional theory calculation coupled with experimentation reveal that a zigzag carbon atom is the most active site for oxygen reduction among several types of carbon defects on graphene nanoribbons in acid electrolyte. This work demonstrates that zigzag carbon is a promising electrocatalyst for low-cost and durable proton exchange membrane fuel cells.