Tailoring molecular architectures of Fe phthalocyanine on nanocarbon supports for high oxygen reduction performance
Tailoring molecular architectures of Fe phthalocyanine on nanocarbon supports for high oxygen reduction performance
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DOI：
10.1039/c5ta01400j
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发表时间：
2015-04
影响因子：
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通讯作者：
Shiming Zhang;Heyou Zhang;X. Hua;Shengli Chen
中科院分区：
文献类型：
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作者：
Shiming Zhang;Heyou Zhang;X. Hua;Shengli Chen
具有成本效益的非贵金属氧还原电催化剂是燃料电池成为可行的发电技术的关键。金属大环化合物如Fe/Co卟啉和酞菁是用于O2还原的优良分子催化剂;但是当在电化学环境中催化ORR时，它们仍然比Pt基材料具有相当少的竞争力。以酞菁铁（FePc）为模型化合物，通过在高比表面积的纳米碳上组装金属大环化合物，可以大大提高金属大环化合物的电催化活性.通过简单的球磨FePc与纳米碳，如石墨烯纳米片和炭黑纳米颗粒，从纳米棒到均匀的薄壳的FePc的分子结构得到。所得碳载FePc复合材料在碱性溶液中表现出比现有技术的碳载Pt更上级的ORR性能，半波电位正移高达60 mV，质量活性增加超过5倍。以及显示，分子-载体相互作用提供了一定程度的控制的金属大环化合物的分子结构，目前的工作表明，FePc分子是本质上更有效的催化在碱性介质中的ORR比铂，因此有很大的前景作为阴极电催化剂在碱性燃料电池。
Cost-effective non-precious metal electrocatalysts for the oxygen reduction reaction (ORR) is the key for fuel cells to become a viable electricity generation technology. Metal macrocyclic compounds such as Fe/Co porphyrins and phthalocyanines are excellent molecular catalysts for O2 reduction; but they are still considerably less competitive than Pt-based materials when catalyzing the ORR in electrochemical environments. Using Fe phthalocyanine (FePc) as a model compound, we show that the electrocatalytic activity of metal macrocyclic compounds for the ORR can be greatly enhanced through tailoring assembling architectures on high-surface-area nanocarbons. By simply ball-milling FePc with nanocarbons, such as graphene nanosheets and carbon-black nanoparticles, molecular architectures of FePc from nanorods to uniform thin shells are obtained. The resulting carbon-supported FePc composites exhibit ORR performance much superior to the state-of-the-art carbon-supported Pt in alkaline solution, with up to a 60 mV positive shift in the half-wave potential and more than 5 times increase in the mass activity. As well as showing that the molecule–support interaction provides a degree of control on the molecular architectures of metal macrocyclic compounds, the present work reveals that the FePc molecule is intrinsically much more efficient than Pt in catalyzing the ORR in alkaline media, and therefore has great prospects as a cathode electrocatalyst in alkaline fuel cells.