通过球磨-煅烧的方法对碳纳米管进行氮掺杂改性。分别以尿素、吡啶、三聚氰胺为氮源,在不同碳氮质量比以及煅烧温度下进行氮掺杂,结果表明,600℃为最佳的氮掺杂煅烧温度;以三聚氰胺为氮源、碳氮比为1∶0.5时NO的转化率要高于其他氮源,350℃时转化率达到峰值。SEM、BET、XRD、FT-IR和XPS等表征结果表明,氮掺入后主要以吡啶氮、吡咯氮和石墨氮的形态存在,同时在碳纳米管表面引入了含氮官能团,改变了碳原子和氮原子的电荷状态,为SCR反应提供了更多的活性位点。

Carbon nanotubes are modified through nitrogen doping using a ball milling-calcination method.With urea,pyridine,and melamine as nitrogen source,respectively,nitrogen doping is carried out at different carbon to nitrogen ratios and calcination temperature.By comparing the original carbon nanotubes,it is found that the optimal nitrogen doping calcination temperature is 600℃.The conversion rate of NO over the carbon nanotubes with melamine as nitrogen source and under a carbon to nitrogen ratio of 1∶0.5 is higher than that over the ones with other nitrogen sources.The conversion rate of NO reaches the peak at 350℃.Combined with the characterizations such as SEM,BET,XRD,FTIR,and XPS,it is demonstrated that nitrogen doping mainly exists in the forms of pyridine nitrogen,pyrrole nitrogen,and graphite nitrogen.Meanwhile,nitrogen-containing functional groups are added on the surface of carbon nanotubes,changing the charge state of carbon and nitrogen atoms,providing more active sites for the SCR reaction.

韩洪轩(2002-),男,本科生,研究方向为新能源科学与工程,hanhxsau2024@163.com;烟征(1986-),女,博士,副教授,研究方向为空气污染控制工程,通讯联系人,yanzheng@sau.edu.cn。