Template-assisted conversion of aniline nanopolymers into non-precious metal FeN/C electrocatalysts for highly efficient oxygen reduction reaction

• Published in: Journal of alloys and compounds Vol. 686; pp. 874 - 882
• Main Authors: Guo, Chaozhong, Wen, Bixia, Liao, Wenli, Li, Zhongbin, Sun, Lingtao, Wang, Chao, Wu, Youcheng, Chen, Jing, Nie, Yunqing, Liao, Jianglan, Chen, Changguo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.11.2016
• Subjects: Electrocatalyst; Fuel cells; Metal-Nx; Oxygen reduction; Pyrrolic-N; Oxygen reduction; Electrocatalyst; Metal-Nx; Pyrrolic-N; Fuel cells
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2016.06.243

Developing high-performance noble-metal-free electrocatalysts for oxygen reduction reaction (ORR) is the key to the commercialization of fuel cells. Here we use a Fe (III)-modified montmorillonite (Fe-MMT) as a solid-state flat-template to synthesize iron and nitrogen-doped carbon electrocatalysts (FeN/C-PANI) for the ORR derived from thermal conversion of aniline nanopolymer at controlled temperatures. The utilization of flat template can hinder thermal agglomeration of aniline nanopolymer and optimize the nitrogen-containing active site density on the surface. We find that this catalyst exhibits a similar ORR electrocatalytic activity with an onset potential of 0.99 V (versus RHE), a major four-electron reaction pathway and a higher stability compared to the state-of-the-art 20 wt% Pt/C catalyst in alkaline medium. Besides, the ORR half-wave potential measured on our catalyst is only 10 mV lower than that on a Pt/C catalyst. Electrochemical poisoning experiments also confirm that the Fe-Nx group inside the FeN/C-PANI can improve the ORR activity and may be one of key components of active sites. The pyrrolic-N species may be mainly responsible for the ORR catalytic activity and may be another essential component of active sites. This study opens a new way to rationally design inexpensive and highly-efficient ORR catalysts by using simple flat compounds as a direct template. •FeN/C-PANI fabricated by a flat-template is firstly used as an ORR catalyst.•The utilization of flat-template helps to hamper agglomeration of ANI nanopolymer.•FeN/C-PANI exhibits excellent ORR electrocatalytic activity and high stability.•The Fe-N and pyrrolic-N species may be key components of catalytically active sites.