| 초록 |
To investigate the effects and roles of iron content, N-doped CNTs grafted on Fe/C were synthesized via the pyrolysis of a mixture comprising dicyandiamide and various contents of Fe2O3/C (0, 20, 40 and 60 wt%). From the results of electrochemical tests (CV and ORR), the catalyst with the highest performance was observed when dicyandiamide was pyrolyzed with Fe2O3/C 20 wt% (Fe-N-C-20) and the order of activity towards ORR was Fe-N-C-20 ＞ Fe-N-C-40 ＞ Fe-N-C-60 ＞ Fe-N-C-0 ＞ Vulcan XC-72R. It was shown that the iron does not act as an active site for ORR, but as a stimulator in doping nitrogen into carbon; as the iron content increased, the amount of nitrogen doping also increased. However, increment of iron content had negative effects on the catalysts for ORR due to a decrease of the surface area of the prepared catalysts, and as a result the activity towards the ORR as a function of the amount of iron content graphically followed a volcano-like shape. |
