Metal-Organic Framework-Derived Bamboo-like Nitrogen-Doped Graphene Tubes as an Active Matrix for Hybrid Oxygen-Reduction Electrocatalysts
Metal-Organic Framework-Derived Bamboo-like Nitrogen-Doped Graphene Tubes as an Active Matrix for Hybrid Oxygen-Reduction Electrocatalysts
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DOI：
10.1002/smll.201402069
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发表时间：
2015-03-25
期刊：
影响因子：
13.3
通讯作者：
Wu, Gang
中科院分区：
文献类型：
--
作者：
Li, Qing;Pan, Hengyu;Wu, Gang
在这项工作中，大尺寸（即，通过双氰胺（DCDA）和乙酸铁（II）的高温石墨化过程，以新型金属有机骨架（MIL-100（Fe））为模板，制备了具有氮掺杂的（直径> 100 nm）石墨烯管。氮掺杂的石墨烯管（N-GT）富铁-氮-碳（Fe-N-C）催化剂在更具挑战性的酸性介质中对氧还原反应（ORR）表现出固有的高活性。此外，为了提高传统Pt催化剂的活性和稳定性，使用ORR活性N-GT作为基质来分散Pt纳米颗粒，以构建独特的杂化Pt阴极催化剂。这是第一次证明高活性Fe-N-C催化剂与Pt纳米颗粒的整合。合成的20% Pt/N-GT复合催化剂表现出显着提高的ORR活性和H-2-空气燃料电池性能相对于那些20% Pt/C，这主要归因于本征活性的N-GT基体沿着以及非贵金属活性中心和Pt纳米颗粒之间可能的协同效应。与传统的Pt/C不同，混合催化剂在加速耐久性测试期间表现出优异的稳定性，这可能是由于独特的高度石墨化的石墨烯管形态，能够提供与Pt纳米颗粒的强相互作用，然后防止其团聚。
In this work, large size (i.e., diameter > 100 nm) graphene tubes with nitrogen-doping are prepared through a high-temperature graphitization process of dicyandiamide (DCDA) and Iron(II) acetate templated by a novel metal-organic framework (MIL-100(Fe)). The nitrogen-doped graphene tube (N-GT)-rich iron-nitrogen-carbon (Fe-N-C) catalysts exhibit inherently high activity towards the oxygen reduction reaction (ORR) in more challenging acidic media. Furthermore, aiming to improve the activity and stability of conventional Pt catalysts, the ORR active N-GT is used as a matrix to disperse Pt nanoparticles in order to build a unique hybrid Pt cathode catalyst. This is the first demonstration of the integration of a highly active Fe-N-C catalyst with Pt nanoparticles. The synthesized 20% Pt/N-GT composite catalysts demonstrate significantly enhanced ORR activity and H-2-air fuel cell performance relative to those of 20% Pt/C, which is mainly attributed to the intrinsically active N-GT matrix along with possible synergistic effects between the non-precious metal active sites and the Pt nanoparticles. Unlike traditional Pt/C, the hybrid catalysts exhibit excellent stability during the accelerated durability testing, likely due to the unique highly graphitized graphene tube morphologies, capable of providing strong interaction with Pt nanoparticles and then preventing their agglomeration.