New catalyst supports prepared by surface modification of graphene- and carbon nanotube structures with nitrogen containing carbon coatings
New catalyst supports prepared by surface modification of graphene- and carbon nanotube structures with nitrogen containing carbon coatings
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DOI：
10.1016/j.jpowsour.2016.11.116
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发表时间：
2017-02
影响因子：
9.2
通讯作者：
Eun-Jin Oh;R. Hempelmann;V. Nica;I. Radev;H. Natter
中科院分区：
文献类型：
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作者：
Eun-Jin Oh;R. Hempelmann;V. Nica;I. Radev;H. Natter
我们提出了一种在石墨烯和碳纳米管（CNT）表面制备含氮碳涂层（NCC）的新方法，该涂层具有更高的电子导电性。改性后的碳体系可作为电催化的催化剂载体，特别是用于聚合物电解质膜燃料电池（PEMFC）。表面改性是通过用含氮离子液体（IL）浸渍碳结构，并按规定的C:N比进行，然后在环境条件下进行热处理。我们研究了主要实验参数（IL量、温度、衬底形貌）对NCC形成的影响。利用电子显微镜（SEM）、透射电镜（TEM）、能量分散x射线分析（EDX）、x射线光电子能谱（XPS）和热萃取分析对产物的结构和化学成分进行了分析。改性后的表面含氮量为29 wt%，在600°C以上的温度下，氮含量急剧下降。将新型催化剂载体用于制备PEMFC阳极，并用极化测量和电化学阻抗谱（EIS）对其进行了表征。与未改性的石墨烯和碳纳米管样品相比，改性系统的电子导电性增加了2倍，并显示出改善的质量传输特性。
We present a new and facile method for preparation of nitrogen containing carbon coatings (NCC) on the surface of graphene- and carbon nanotubes (CNT), which has an increased electronic conductivity. The modified carbon system can be used as catalyst support for electrocatalytic applications, especially for polymer electrolyte membrane fuel cells (PEMFC). The surface modification is performed by impregnating carbon structures with a nitrogen containing ionic liquid (IL) with a defined C:N ratio, followed by a thermal treatment under ambient conditions.We investigate the influence of the main experimental parameters (IL amount, temperature, substrate morphology) on the formation of the NCC. Additionally, the structure and the chemical composition of the resulting products are analyzed by electron microscopic techniques (SEM, TEM), energy disperse X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS) and hot extraction analysis. The modified surface has a nitrogen content of 29 wt% which decreases strongly at temperatures above 600 °C. The new catalyst supports are used for the preparation of PEMFC anodes which are characterized by polarization measurements and electrochemical impedance spectroscopy (EIS). Compared to unmodified graphene and CNT samples the electronic conductivity of the modified systems is increased by a factor of 2 and shows improved mass transport properties.