In the present work,nitrogen-doped carbon spheres were synthesized through a simple hydro-thermal treatment using glucose and melamine as inexpensive carbon and nitrogen sources,re-spectively.The ratio of melamine to glucose and annealing temperature were optimized.The final optimal sample exhibited a catalytic activity for the oxygen reduction reaction(ORR)that was supe-rior than that of commercial 20%Pt/C in 0.1 mol/L KOH.It revealed an onset potential of-22.6 mV and a half-wave potential of-133.6 mV(vs.Ag/AgCl),which are 7.2 and 5.9 mV more positive than those of the 20%Pt/C catalyst,respectively,as well as a limiting current density of 4.6 mA/cm^(2),which is 0.2 mA/cm^(2)higher than that of the 20%Pt/C catalyst.The catalyst also exhibited higher stability and superior durability against methanol than 20%Pt/C.Moreover,ORRs on this catalyst proceed through a more effective 4 e^(-)path.The above mentioned superiority of the as-prepared catalyst makes it promising for fuel cells.
Jinhui TongWenyan LiLili BoWenhui WangYuliang LiTao LiQi ZhangHaiyan Fan
