ELECTROCATALYTIC PERFORMANCE OF NITROGEN-DOPED CARBON NANOTUBE-BASED NON-PRECIOUS METAL CATALYSTS FOR OXYGEN ELECTROREDUCTION

摘要

Carbon nanotubes (CNTs) attracted world-wide interest for their fantastic properties. To improve the electronic properties, chemical reactivity and mechanical properties of CNTs, heteroatom atoms such as boron or nitrogen were introduced. Nitrogen atom has similar diameter with carbon atom, but contains one more electron. Therefore, N-doped CNTs can improve the conductivity while without causing large distortion of the structure of CNTs Graphitic nitrogen and pyridinic nitrogen were reported as the two common forms of nitrogen atoms bonding into N-doped CNTs. For graphitic nitrogen, nitrogen atoms bond with three carbon atoms providing an electron into n system, while for pyridinic nitrogen, nitrogen atoms bond with two carbon atoms to form C=N. Pyridinic nitrogen-doped carbon structures have been reported to exhibit excellent electrocatalytic performance for oxygen reduction reaction (ORR) in fuel cells The pyridinic nitrogen content in N-doped CNTs significantly influences the electron transfer and electrocatalytic properties.