Hydrothermal synthesis of Fe₂O₃/polypyrrole/graphene oxide composites as highly efficient electrocatalysts for oxygen reduction reaction in alkaline electrolyte

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• 作者：Suzhen Ren^a ; ^{rensz@dlut.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Shaobo Ma^a ; Ying Yang^a ; Qing Mao^b ; Ce Hao^a
• 关键词：Non-precious metal electrocatalyst ; Oxygen reduction reaction ; Fe2O3/polypyrrole/graphene oxide ; Fe-N-C ; Long term stability
• 刊名：Electrochimica Acta
• 出版年：2015
• 出版时间：1 October 2015
• 年：2015
• 卷：178
• 期：Complete
• 页码：179-189
• 全文大小：1349 K

文摘

Advantages in low cost, and excellent catalytic activity of Fe-based nanomaterials dispersed on nitrogen-doped graphene supports render them to be good electrocatalysts for the oxygen reduction reaction (ORR) in fuel cells. Here, Fe₂O₃/polypyrrole/graphene oxide (Fe₂O₃/Ppy/GO) composites with the Fe₂O₃ embedded in the Ppy modified GO are synthesized using hydrothermal method. With an optimal iron atom content ratio of 1.6% in graphene oxide and heat treatment at 800 °C, the Fe₂O₃/Ppy/GO exhibited enhanced catalytic performance for ORR with the onset potential of −0.1 V (vs SCE), cathodic potential of −0.24 V (vs SCE), an approximate 4e⁻ transfer process in O₂-saturated 0.1 M KOH, and superior stability that only reduced 5% catalytic activity after 5000 cycles. The decisive factors in improving the electrocatalytic and durable performance are the intimate and large contact interfaces between nanocrystallines of Fe₂O₃ and Ppy/GO, in addition to the high electron withdrawing/storing ability and the high conductivity of GO doped with nitrogen from Ppy during the hydrothermal reaction. The Fe₂O₃/Ppy/GO showed significantly improved ORR properties and confirmed that Fe-N-C-based electrocatalysts played a key role in fuel cells.