Sputter glancing angle deposition (GLAD) technique was used to fabricate 50 and 200 nm long tilted
Pt nanorods on glassy carbon electrodes with weight loadings of 0.042 and 0.117 mg cm-2, respectively.
GLAD-tilted Pt nanorod electrodes were investigated as potential electrocatalysts for proton exchange membrane
fuel cells utilizing cyclic voltammetry (CV) and rotatingdisk electrode (RDE) techniques in aqueous perchloric acid
(HClO4) to determine their oxygen reduction reaction (ORR) activities and stabilities. The CV results demonstrate
that the tilted Pt nanorods electrocatalyst exhibits more positive oxide reduction peak potential compared to
conventional carbon supported Pt particles (Pt/C), indicating that tilted GLAD Pt nanorods are less oxophilic than
Pt/C. In addition, the multiple CV cycles in acidic electrolyte showed that tilted Pt nanorods are significantly
more stable than Pt/C. Furthermore, specific ORR activities of tilted Pt nanorods determined by RDE technique were
analyzed and compared to literature values of Pt/C and vertically aligned Pt nanorod electrodes. The room temperature
RDE results revealed that tilted Pt nanorods demonstrate higher area-specific activity than that of Pt/C
catalyst. The enhanced ORR activity of tilted Pt nanorods is due to their large crystallite size and possible dominance of the preferred crystal orientations for ORR. However, the tilted Pt nanorods showed lower mass-specific activity than
Pt/C electrocatalyst caused by the large diameters of the tilted Pt nanorods. Overall ORR activity and stability of
tilted Pt nanorods were found to be comparable to those of vertical ones.