NITROGEN-DOPED CARBON NANOTUBES: A HIGHLY SELECTIVE OXYGEN REDUCTION ELECTROCATALYST FOR FUEL CELLS

摘要

In recent years, there has been great interest in the search and development of Non-Precious Catalysts (NPCs), in particular the nitrogen-containing carbon nanostructured catalysts, as an alternative to platinum for ORR [1-3]. Various research groups reported the activity and stability of nitrogen-containing carbon nanostructures towards ORR in basic, neutral and acidic electrolyte media [4-10]. The experimental results accumulated over the years indicate that carbon and nitrogen without any metal (in the form of CN_x) [3-10], or those with metal (in the form of MN_xC_y where M = iron or cobalt) [1,2], form highly active ORR catalysts. Yet to date, there exists much controversy over the actual composition and structure of ORR active sites. Better understanding of the active site in these NPCs may lead to the development of materials that could completely eliminate the need for platinum in the energy conversion devices.