title: 2D Nanoporous Fe-N/C Nanosheets as Highly Efficient Non-Platinum Electrocatalysts for Oxygen Reduction Reaction in Zn-Air Battery.
abstract: It is an ongoing challenge to fabricate nonprecious oxygen reduction reaction (ORR) catalysts that can be comparable to or exceed the efficiency of platinum. A highly active non-platinum self-supporting Fe-N/C catalyst has been developed through the pyrolysis of a new type of precursor of iron coordination complex, in which 1,4-bis(1H-1,3,7,8-tetraazacyclopenta(1)phenanthren-2-yl)benzene (btcpb) functions as a ligand complexing Fe(II) ions. The optimal catalyst pyrolyzed at 700 °C (Fe-N/C-700) shows the best ORR activity with a half-wave potential (E1/2) of 840 mV versus reversible hydrogen electrode (RHE) in 0.1 m KOH, which is more positive than that of commercial Pt/C (E1/2: 835 mV vs RHE). Additionally, the Fe-N/C-700 catalyst also exhibits high ORR activity in 0.1 m HClO4with the onset potential and E1/2comparable to those of the Pt/C catalyst. Notably, the Fe-N/C-700 catalyst displays superior durability (9.8 mV loss in 0.1 m KOH and 23.6 mV loss in 0.1 m HClO4for E1/2after 8000 cycles) and better tolerance to methanol than Pt/C. Furthermore, the Fe-N/C-700 catalyst can be used for fabricating the air electrode in Zn-air battery with a specific capacity of 727 mA hg-1at 5 mA cm-2and a negligible voltage loss after continuous operation for 110 h.
authors: Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China.
authors: Zheng Kun
authors: ZK
authors: Yang
authors: Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China.
authors: Ling
authors: L
authors: Lin
authors: Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China. anwuxu@ustc.edu.cn.
authors: An-Wu
authors: AW
authors: Xu
keywords: Fe-N-carbon; Zn-air batteries; nanoporous materials; nanosheets; oxygen reduction reaction