Pt Nanoparticles Supported on Nitrogen-Doped Porous Carbon Nanospheres as an Electrocatalyst for Fuel Cells

Nitrogen-doped porous carbon nanospheres (PCNs) with a high surface area were prepared by chemical activation of nonporous carbon nanospheres (CNs). CNs were obtained via carbonization of polypyrrole nanospheres (PNs) that were synthesized by ultrasonic polymerization of pyrrole. The catalysts Pt/PCN, Pt/CN, and Pt/PN were prepared by depositing Pt nanoparticles on supports PCNs, CNs, and PNs, respectively, using ethylene glycol chemical reduction. Nitrogen adsorption, X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy were employed to characterize samples. It was found that after chemical activation using KOH, PCNs containing N functional groups (mainly N-6 and N-Q) possessed a microporous structure with a high surface area of 1010 m2/g and a particle size of less than 100 nm. The electrochemical properties of samples Pt/PCN, Pt/CN, and Pt/PN, together with commercial catalysts E-TEK (40 wt % Pt loading), wer...