Investigation of Further Improvement of Platinum Catalyst Durability with Highly Graphitized Carbon Nanotubes Support

The highly graphitized multiwalled carbon nanotubes (HG-MWCNT) were obtained by heat treatment at 2800 °C upon the as-obtained chemically vapor deposited multiwalled carbon nanotubes (CVD−MWCNT). The graphitization behavior was studied by X-ray diffraction and Raman spectroscopy. The results indicated that the obtained HG-MWCNT had a high degree of graphitization (95.3%), while it was only 39.5% for the as-obtained CVD−MWCNT. Electrochemical investigation suggested that the HG-MWCNT had a lower corrosion rate than the original MWCNT, which can be attributed to the less surface defects on the HG-MWCNT with the increase of the graphitization degree. The durability of the corresponding Pt/CNT catalyst was discussed. The results revealed that Pt/HG-MWCNT using the highly graphitized carbon nanotubes as the supporting material had a higher electrochemical stability, which is due to the lower corrosion rate of HG-MWCNT and the stronger interaction between metal and carbon support.