The highly graphitized multiwalled carbon nanotubes (HG-MWCNT) were obtained by heat treatment at2800
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 indicatedthat the obtained HG-MWCNT had a high degree of graphitization (95.3%), while it was only 39.5% for theas-obtained CVD-MWCNT. Electrochemical investigation suggested that the HG-MWCNT had a lowercorrosion 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 catalystwas discussed. The results revealed that Pt/HG-MWCNT using the highly graphitized carbon nanotubes asthe supporting material had a higher electrochemical stability, which is due to the lower corrosion rate ofHG-MWCNT and the stronger interaction between metal and carbon support.