Certain nitrogen functionalities on carbon nanofiber support for improving platinum performance

• Certain nitrogen functionalities can be introduced into carbon nanofiber network by plasma modification.
• Plasma modification can preserve the highly graphitic structure of carbon nanofiber support.
• N-modified CNF exhibits a significant improvement in Pt electrochemical activity and stability than pristine CNF support.
• Pt/CNF–NH3 electrode exhibits the highest Pt utilization, electrochemical activity, and poisoning-resistance ability.

Nitrogen (N) modification of carbon nanomaterial, which plays a critical role in improving platinum (Pt) performance, has shown fascinating applications. N-doped carbon nanofiber (CNF)-supported platinum catalysts were produced by an approach combined of plasma-enhanced chemical vapor deposition and in situ plasma activation. This approach can successfully introduce nitrogen functionalities into a carbon network, and at the same time, preserve the highly graphitic structure of the carbon support. XPS results indicate that NH3 plasma modification mainly creates pyridinic nitrogen functionalities, while N2 plasma modification mainly increases the percentage of pyrrolic nitrogen in the carbon network, which suggests a modification of certain nitrogen functionalities on the carbon support. By correlating TEM and XPS data with electrochemical measurements, we conclude that the N-modified CNF exhibits a significant improvement in Pt electrochemical activity and stability than pristine CNF support and Pt/CNF–NH3 electrode with smallest Pt particle size, highest percentage of pyridinic nitrogen, exhibits the highest Pt utilization, electrochemical activity, and poisoning-resistance ability. Our study gives both insights on the influence of N modification of the carbon support in platinum catalytic effectiveness and a route for formation of certain nitrogen functionalities on the carbon support. This will be important for the further development of Pt catalysts.

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