Yao Yi, Zhang Bingqing, Shi Jingying, Yang Qihua
†State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.
‡Graduate School of the Chinese Academy of Sciences, Beijing 100049, China.
ACS Appl Mater Interfaces. 2015 Apr 8;7(13):7413-20. doi: 10.1021/acsami.5b01233. Epub 2015 Mar 27.
We report a facile method for the synthesis of nitrogen-doped carbon nanotubes (NCNTs) from melamine-formaldehyde (MR) resin using FeCl3 or supported FeCl3 as catalysts. The growth of NCNTs follows a decomposition-reconstruction mechanism, in which the polymer precursor would totally gasify during pyrolysis process and then transformed into carbon nanotubes. The morphology of the NCNTs could be adjusted via applying different catalyst supports and three kinds of carbon nanotubes with outer-diameter of 20-200 nm and morphologies of either bamboo-like or hollow interiors were obtained. Nitrogen atoms in the materials were mainly in the form of pyridinic and quaternary form while the formation of iron species strongly depended on the interaction between iron precursor and organic carbon/nitrogen sources. All MR resin derived NCNTs are efficient toward oxygen reduction reaction (ORR). NCNTs prepared using FeCl3 as catalyst showed the highest ORR activity with half-wave potentials of -0.17 V, which is comparable with commercial Pt/C. This is probably because of a close contact between MR resin and iron precursor could enhance the iron-ligand coordination strength and thus steadily improve the performance of the catalyst.
我们报道了一种简便的方法，以三聚氰胺 - 甲醛（MR）树脂为原料，使用FeCl3或负载型FeCl3作为催化剂来合成氮掺杂碳纳米管（NCNT）。NCNT的生长遵循分解 - 重构机制，在此机制中，聚合物前驱体在热解过程中会完全气化，然后转化为碳纳米管。通过应用不同的催化剂载体可以调节NCNT的形态，获得了三种外径为20 - 200 nm、形态为竹节状或内部中空的碳纳米管。材料中的氮原子主要以吡啶型和季铵型形式存在，而铁物种的形成强烈依赖于铁前驱体与有机碳/氮源之间的相互作用。所有由MR树脂衍生的NCNT对氧还原反应（ORR）都具有高效性。以FeCl3作为催化剂制备的NCNT表现出最高的ORR活性，其半波电位为 - 0.17 V，与商业Pt/C相当。这可能是因为MR树脂与铁前驱体之间的紧密接触可以增强铁 - 配体配位强度，从而稳定地提高催化剂的性能。
