4 Catalyst Materials for Oxygen Reduction Reaction
147
Fig. 4.42 a chronoampelarization curves of Pt-C/GC (1) and VA-NCNTs/GC (2) catalysts against
Co, b VA-NCNTs / GC (below) and Pt-C/GC (above) catalyst cycle scan ~100,000 times stability
comparison [335]
in the process of ORR reaction, resulting in the decrease of electrochemical active
area, thus the performance of ORR will decline [339]. Because of the stability of
NCNTs and C-N structure, NCNT can maintain good stability in the process of ORR
reaction.
The enhancement of ORR activity of NCNTs is due to the change of electronic
structure caused by the doping of N atom in CNTs, so the activity of NCNTs should
be related to the content and form of N atom. Sun et al. [341] studied the effect
of nitrogen content on the oxygen reduction performance of nitrogen-doped carbon
nanotubes. They controlled the nitrogen content in carbon nanotubes by adjusting the
amount of melamine added during the growth of carbon nanotubes. Their research
has shown that their oxygen reduction performance increases with the increase of
Fig. 4.43 a-c possible catalytic ORR reaction steps of C − N, HN − CNT, and FN − CNTs bond
active sites, d-f corresponding reaction energy barrier [361]
147
Fig. 4.42 a chronoampelarization curves of Pt-C/GC (1) and VA-NCNTs/GC (2) catalysts against
Co, b VA-NCNTs / GC (below) and Pt-C/GC (above) catalyst cycle scan ~100,000 times stability
comparison [335]
in the process of ORR reaction, resulting in the decrease of electrochemical active
area, thus the performance of ORR will decline [339]. Because of the stability of
NCNTs and C-N structure, NCNT can maintain good stability in the process of ORR
reaction.
The enhancement of ORR activity of NCNTs is due to the change of electronic
structure caused by the doping of N atom in CNTs, so the activity of NCNTs should
be related to the content and form of N atom. Sun et al. [341] studied the effect
of nitrogen content on the oxygen reduction performance of nitrogen-doped carbon
nanotubes. They controlled the nitrogen content in carbon nanotubes by adjusting the
amount of melamine added during the growth of carbon nanotubes. Their research
has shown that their oxygen reduction performance increases with the increase of
Fig. 4.43 a-c possible catalytic ORR reaction steps of C − N, HN − CNT, and FN − CNTs bond
active sites, d-f corresponding reaction energy barrier [361]