부산대학교 도서관

Fine Pt nanoparticles functionalized with Gd3+hydroxide/oxide species were prepared on multiwalled carbon nanotubes (MWCNTs) containing polypyrrole matrix overlayers and found to exhibit remarkable electrocatalytic performance in the oxygen reduction reaction (ORR). Characterization via transmission electron microscopy, scanning transmission electron microscopy with electron energy loss spectroscopy, X-ray absorption fine structure, and X-ray photoelectron spectroscopy revealed that the Gd3+hydroxide/oxide species were located in close proximity to the Pt0nanoparticles on the MWCNTs. The prepared Pt nanoparticle–Gd hydroxide/oxide composites exhibited superior ORR activity to Gd-free Pt nanoparticles prepared in a similar manner, and the decoration with the Gd species suppressed Pt oxidation and accelerated Pt oxide reduction, as demonstrated by cyclic voltammetry and in situPt LIII-edge X-ray absorption near-edge structure analysis under potential application. The effect of the Gd loading on the ORR performance was also examined, revealing the existence of an optimal Gd loading beyond which further Gd incorporation resulted in aggregation of the Gd3+domains and decreased crystallinity of the Pt nanoparticles.