氮掺杂碳纳米管对其负载的Ru催化剂上合成氨的促进作用

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10～15 nm,壁厚10～20 nm.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...

Enhanced Ammonia Synthesis Activity of Ru Supported on Nitrogen-Doped Carbon Nanotubes

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.