Theoretical Investigation on the Reaction Pathways of the Oxygen Reduction Reaction on Graphene Codoped with Manganese and Phosphorus as a Potential Nonprecious Metal Catalyst

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• 作者：Xiaowan Bai ; Prof. Dr. Erjun Zhao ; Kai Li ; Dr. Ying Wang ; Dr. Menggai Jiao ; Feng He ; Xiaoxu Sun ; Prof. Dr. Jucai Yang and Prof. Dr. Zhijian Wu
• 刊名：ChemCatChem
• 出版年：2016
• 出版时间：November 8, 2016
• 年：2016
• 卷：8
• 期：21
• 页码：3353-3360
• 全文大小：2823K
• ISSN：1867-3899

文摘

Nonprecious-metal-doped graphene catalysts have been proposed recently as promising candidates to substitute Pt catalysts for the oxygen reduction reaction (ORR) in fuel cells. We codoped Mn and P in divacancy graphene (MnP_x, x=1–4) and we studied the stability and the catalytic activity for the ORR. The calculated formation energy indicates that MnP₂-doped divacancy graphene is energetically the most stable. The MnP₂ moiety and its adjacent six C atoms are catalytically active sites for the ORR. The kinetically most favorable pathway is the hydrogenation of OOH to form O+H₂O, which is a four-electron process. The rate-determining step is the second H₂O formation, which has an energy barrier of 0.91 eV. The free energy diagrams show that for OOH hydrogenation into O+H₂O all of the elementary steps are downhill at potentials of 0.0–0.67 V except for the second H₂O formation.