TY - JOUR
T1 - Influence of different carbon nanostructures on the electrocatalytic activity and stability of Pt supported electrocatalysts
AU - Stamatin, Serban Nicolae
AU - Borghei, Maryam
AU - Andersen, Shuang Ma
AU - Veltzé, Sune
AU - Ruiz, Virginia
AU - Kauppinen, Esko
AU - Skou, Eivind M.
PY - 2014
Y1 - 2014
N2 - Commercially available graphitized carbon nanofibers and multi-walled carbon nanotubes, two carbon materials with very different structure, have been functionalized in a nitric–sulfuric acid mixture. Further on, the materials have been platinized by a microwave assisted polyol method. The relative degree of graphitization has been estimated by means of Raman spectroscopy and X-ray diffraction while the relative concentration of oxygen containing groups has been estimated by X-ray photoelectron spectroscopy, which resulted in a graphitic character trend: Pt/GNF > Pt/F-GNF ⋙ Pt/MWCNT > Pt/F-MWCNT. Transmission electron microscopy showed that the Pt particle size is around 3 nm for all samples, which was similar to the crystallite size obtained by X-ray diffraction. The activity towards electrochemical reduction of oxygen has been quantified using the thin-film rotating disk electrode, which has shown that all the samples have a better activity than the commercially available electrocatalysts. The trend obtained for the graphitic character maintained for the electrochemical activity, while the reverse trend has been obtained for the accelerated ageing test. Long-term potential cycling has demonstrated that the functionalization improves the stability for multi-walled carbon nanotubes, at the cost of decreased activity.
AB - Commercially available graphitized carbon nanofibers and multi-walled carbon nanotubes, two carbon materials with very different structure, have been functionalized in a nitric–sulfuric acid mixture. Further on, the materials have been platinized by a microwave assisted polyol method. The relative degree of graphitization has been estimated by means of Raman spectroscopy and X-ray diffraction while the relative concentration of oxygen containing groups has been estimated by X-ray photoelectron spectroscopy, which resulted in a graphitic character trend: Pt/GNF > Pt/F-GNF ⋙ Pt/MWCNT > Pt/F-MWCNT. Transmission electron microscopy showed that the Pt particle size is around 3 nm for all samples, which was similar to the crystallite size obtained by X-ray diffraction. The activity towards electrochemical reduction of oxygen has been quantified using the thin-film rotating disk electrode, which has shown that all the samples have a better activity than the commercially available electrocatalysts. The trend obtained for the graphitic character maintained for the electrochemical activity, while the reverse trend has been obtained for the accelerated ageing test. Long-term potential cycling has demonstrated that the functionalization improves the stability for multi-walled carbon nanotubes, at the cost of decreased activity.
KW - Fuel cell
KW - Oxygen reduction reaction
KW - Stability
KW - Carbon nanofibers
KW - Platinum nanoparticles
KW - Carbon nanotubes
U2 - 10.1016/j.ijhydene.2014.03.052
DO - 10.1016/j.ijhydene.2014.03.052
M3 - Journal article
SN - 0360-3199
VL - 39
SP - 8215
EP - 8224
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
IS - 16
ER -