Phenylenediamine-Based FeNx/C Catalyst with High Activity for Oxygen Reduction in Acid Medium and Its Active-Site Probing

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• 作者：Qiang Wang ; Zhi-You Zhou ; Yu-Jiao Lai ; Yong You ; Jian-Guo Liu ; Xia-Ling Wu ; Ephrem Terefe ; Chi Chen ; Lin Song ; Muhammad Rauf ; Na Tian ; Shi-Gang Sun
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：August 6, 2014
• 年：2014
• 卷：136
• 期：31
• 页码：10882-10885
• 全文大小：286K
• ISSN：1520-5126

文摘

High-temperature pyrolyzed FeN_x/C catalyst is one of the most promising nonprecious metal electrocatalysts for oxygen reduction reaction (ORR). However, it suffers from two challenging problems: insufficient ORR activity and unclear active site structure. Herein, we report a FeN_x/C catalyst derived from poly-m-phenylenediamine (PmPDA-FeN_x/C) that possesses high ORR activity (11.5 A g^鈥? at 0.80 V vs RHE) and low H₂O₂ yield (<1%) in acid medium. The PmPDA-FeN_x/C also exhibits high catalytic activity for both reduction and oxidation of H₂O₂. We further find that the ORR activity of PmPDA-FeN_x/C is not sensitive to CO and NO_x but can be suppressed significantly by halide ions (e.g., Cl^{鈥?/sup>, F鈥?/sup>, and Br鈥?/sup>) and low valence state sulfur-containing species (e.g., SCN鈥?/sup>, SO₂, and H₂S). This result reveals that the active sites of the FeN_x/C catalyst contains Fe element (mainly as FeIII at high potentials) in acid medium.}