Carbon Defect-Induced Reversible Carbon-Oxygen Interfaces for Efficient Oxygen Reduction
Carbon Defect-Induced Reversible Carbon-Oxygen Interfaces for Efficient Oxygen Reduction
复制标题
碳缺陷引起的可逆碳-氧界面，用于有效的氧还原
DOI：
10.1021/acsami.8b14323
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发表时间：
2018-11-21
影响因子：
9.5
通讯作者：
Kang, Zhenhui
中科院分区：
文献类型：
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作者：
Wu, Qilong;Liu, Qian;Kang, Zhenhui
制备能够在酸性介质和燃料电池系统中良好工作的无金属氧还原反应电催化剂是一个巨大的挑战。本文采用自牺牲模板法和固相反应策略制备了具有丰富缺陷位的无金属碳材料C-900。C-900在碱性介质中表现出优于20%Pt/C的上级性能，在酸性介质中表现出接近20%Pt/C的性能。因此，它可以应用于空气呼吸式燃料电池（没有额外的操作压力）作为阴极催化剂，它表现出高性能（1160 W L-1，类似于62%的20%Pt/C），具有优异的稳定性。用氧程序升温脱附法研究了O-2在C-900上的强选择性化学吸附。同步辐射X射线吸收光谱证实，C-900的优异化学吸附性能可能来源于大量的碳缺陷位。丰富的缺陷位和优异的化学吸附性能可以诱导可逆的碳-氧界面，从而获得优异的ORR活性。
It is a great challenge to fabricate a metal-free oxygen reduction reaction (ORR) electrocatalyst that can operate well in the acidic medium and fuel cells system. Here, a metal-free carbon material C-900 with abundant defect sites is fabricated by a self-sacrificed template and a solid-state reaction strategy. C-900 shows a superior performance to 20% Pt/C in alkaline medium and a performance closer to 20% Pt/C in acidic condition. It can thus be applied in air-breathing fuel cell (without extra operation pressure) as the cathode catalyst, which shows a high performance (1160 W L-1; similar to 62% of 20% Pt/C) with excellent stability. By using oxygen temperature-programmed desorption, the strong selective chemisorption of O-2 on C-900 has been revealed. The excellent chemisorption property of C-900 may originate from the large amounts of carbon defect sites, which have been confirmed by synchrotron radiation-based X-ray absorption spectroscopy. The rich defect sites and excellent chemisorption property can thus induce reversible carbon-oxygen interface for the excellent ORR activity.