Pt-based electrocatalysts for polymer electrolyte membrane fuel cells prepared by supercritical deposition technique


Bayrakceken A., Smirnova A., Kitkamthorn U., Aindow M., Turker L., Eroglu I. , ...More

JOURNAL OF POWER SOURCES, vol.179, no.2, pp.532-540, 2008 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 179 Issue: 2
  • Publication Date: 2008
  • Doi Number: 10.1016/j.jpowsour.2007.12.086
  • Title of Journal : JOURNAL OF POWER SOURCES
  • Page Numbers: pp.532-540
  • Keywords: supercritical carbon dioxide deposition, electrocatalyst, carbon, polymer electrolyte membrane fuel cell, platinum, PLATINUM-BASED ELECTROCATALYSTS, OXYGEN REDUCTION REACTION, SUPPORTED CATALYSTS, CARBON NANOTUBES, ELECTROCHEMICAL REDUCTION, AEROGEL NANOCOMPOSITES, NANOPARTICLES, PERFORMANCE, METHANOL, CATHODE

Abstract

Pt-based electrocatalysts were prepared on different carbon supports which are multiwall carbon nanotubes (MWCNTs), Vulcan XC 72R (VXR) and black pearl 2000 (BP2000) using a supercritical carbon dioxide (ScCO2) deposition technique. These catalysts were characterized by using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and cyclic voltammetry (CV). XRD and HRTEM results demonstrated that the ScCO2 deposition technique enables a high surface area metal phase to be deposited, with the size of the Pt particles ranging from 1 to 2 nm. The electrochemical surface areas (ESAs) of the prepared electrocatalysts were compared to the surface areas of commercial ETEK Pt/C (10 wt% Pt) and Tanaka Pt/C (46.5 wt% Pt) catalysts. The CV data indicate that the ESAs of the prepared Pt/VXR and Pt/MWCNT catalysts are about three times larger than that of the commercial ETEK catalyst for similar (10 wt% Pt) loadings. Oxygen reduction activity was investigated by hydrodynamic voltammetry. From the slope of Koutecky-Levich plots, the average number of electrons transferred in the oxygen reduction reaction (ORR) was 3.5, 3.6 and 3.7 for Pt/BP2000, Pt/VXR and Pt/MWCNT, correspondingly, which indicated almost complete reduction of oxygen to water. (C) 2008 Published by Elsevier B.V.