摘要
以乙腈为碳源和氮源,采用化学气相沉积法制备了氮掺杂的碳纳米管.电子显微镜观察表明,样品形貌为中空的多壁纳米管,管腔大小10～15nm,壁厚10～20nm.X射线光电子能谱结果表明,氮已掺杂到碳纳米管结构中,主要以吡啶型氮和取代型氮存在.结合X射线衍射和拉曼光谱结果发现,随着制备温度的升高,氮掺杂量减少,但纳米管的石墨化程度提高.与未掺杂碳纳米管相比,氮掺杂碳纳米管负载的Ru催化剂上催化合成氨反应活性增加,于650oC制得的掺氮碳纳米管负载的Ru催化剂活性相对最高,这可能是由于载体中氮掺杂和管壁石墨化的综合作用所致.
Nitrogen-doped carbon nanotubes（NCNTs）were synthesized via chemical vapor deposition using acetonitrile as the carbon and nitrogen sources.Transmission electron microscopic characterization showed clearly tubular morphology of NCNTs with inner diameter of 10-15 nm and wall thickness of 10-20 nm.X-ray photoelectron spectroscopy（XPS）indicated that nitrogen species were incorporated into CNTs and the predominating type of nitrogen species were pyridinic and quaternary nitrogen.XPS,X-ray diffraction,and Raman spectros-copy showed that with increasing temperature the total amount of nitrogen species decreased but the nanotubes were better graphitized.Ru supported on NCNTs exhibited an obviously enhanced activity in ammonia synthesis as compared with the CNT-supported Ru catalyst.In particular,in the temperature range of 550～750 C,the NCNTs obtained at 650 ？C after deposition of Ru yielded a better activity,which was o most likely attributed to the promoting effect of nitrogen doping and the graphitization of nanotubes.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2011年第8期1418-1423,共6页
基金
国家自然科学基金(11079005
21033009)~~
关键词
化学气相沉积
氮掺杂
合成氨
钌
碳纳米管
chemical vapor deposition
nitrogen-doped
carbon nanotube
ammonia synthesis
ruthenium
