Preparation and anode property of Pt-CeO 2 electrodes supported on carbon black for direct methanol fuel cell applicatio
- PDF / 355,507 Bytes
- 9 Pages / 585 x 783 pts Page_size
- 93 Downloads / 262 Views
Ajayan Vinu International Center for Young Scientist, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
Hidehiko Kobayashi Faculty of Engineering, Saitama University, Saitama City, Saitama 338-8570, Japan
John Drennan Centre for Microscopy and Microanalysis, The University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
Ding-Rong Ou Ecomaterials Center, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan (Received 16 January 2006; accepted 5 May 2006)
A platinum (Pt) on pure ceria (CeO2) supported by carbon black (CB) anode was synthesized using a combined process of precipitation and coimpregnation methods. The electrochemical activity of methanol oxidation reaction on synthesized Pt-CeO2/CB anodes was investigated by cyclic voltammetry and chronoamperometry experimentation. To improve the anode property on Pt-CeO2/CB, the influence of particle morphology and particle size on anode properties was examined. The morphology and particle size of the pure CeO2 particles could be controlled by changing the preparation conditions. The anode properties (i.e., peak current density and onset potential for methanol oxidation) were improved by using nanosize CeO2 particles. This indicates that a larger surface area and higher activity on the surface of CeO2 improve the anode properties. The influence of particle morphology of CeO2 on anode properties was not very large. The onset potential for methanol oxidation reaction on Pt-CeO2/CB, which consisted of CeO2 with a high surface area, was shifted to a lower potential compared with that on the anodes, which consisted of CeO2 with a low surface area. The onset potential on Pt-CeO2/CB at 60 °C became similar to that on the commercially available Pt-Ru/carbon anode. We suggest that the rate-determining steps of the methanol oxidation reaction on Pt-CeO2/CB and commercially available Pt-Ru/carbon anodes are different, which accounts for the difference in performance. In the reaction mechanism on Pt-CeO2/CB, we conclude that the released oxygen species from the surface of CeO2 particles contribute to oxidation of adsorbed CO species on the Pt surface. This suggests that the anode performance of the Pt-CeO2/CB anode would lead to improvements in the operation of direct methanol fuel cells at 80 °C by the enhancement of diffusion of oxygen species created from the surface of nanosized CeO2 particles. Therefore, we conclude that fabrication of nanosized CeO2 with a high surface area is a key factor for development of a high-quality Pt-CeO2/CB anode in direct methanol fuel cells. I. INTRODUCTION
Polymer membrane fuel cells have been put forward as the next alternative power generation system for clean a)
Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/JMR.2006.0281 2314
J. Mater. Res., Vol. 21, No. 9, Sep 2006
and efficient electricity from hydrogen. With this comes the difficulty of being able to adequately store hydrogen, a challenge that still has not been solved. An alte
Data Loading...
