Carbon-supported Pt-Ru (Pt-Ru/C) is generally used as catalyst in direct methanol fuel cell anodes. For a high catalytic activity Pt-Ru deposits should display nanometric dimensions and should be uniformly distributed on the carbon surface with an optimized interparticle distance, as well as their morphology should be mesoporous to improve the diffusion of the aqueous and gaseous species involved in the methanol electrooxidation. Besides the different synthesis methods developed to prepare catalysts with these properties, also the choice of the carbon support is crucial, affecting both the deposit morphology and the catalyst performance. Carbon supports should display a high surface area for a high catalytic surface at reduced noble metal content, as well as they should guarantee a good electrical contact among the metal particles and between the catalyst and the current collector. Hence carbons should have a low electrical resistance and a suitable mesoporous high “accessible” surface area. In this paper different commercial high surface area-carbon supports were investigated and data of the electrochemical, structural and morphological characterization of carbon powders and carbon electrodes with Nafion as proton conductor binder are reported. Supported Pt-Ru catalysts were prepared by electrochemical deposition on the different carbon/Nafion electrodes, and the effect of different carbon/Nafion supports on the structure, morphology and catalytic activity during electrooxidation of methanol of the Pt-Ru deposits is discussed.
Carbon supports for electrodeposited Pt-Ru catalysts
MASTRAGOSTINO, MARINA;SOAVI, FRANCESCA
2004
Abstract
Carbon-supported Pt-Ru (Pt-Ru/C) is generally used as catalyst in direct methanol fuel cell anodes. For a high catalytic activity Pt-Ru deposits should display nanometric dimensions and should be uniformly distributed on the carbon surface with an optimized interparticle distance, as well as their morphology should be mesoporous to improve the diffusion of the aqueous and gaseous species involved in the methanol electrooxidation. Besides the different synthesis methods developed to prepare catalysts with these properties, also the choice of the carbon support is crucial, affecting both the deposit morphology and the catalyst performance. Carbon supports should display a high surface area for a high catalytic surface at reduced noble metal content, as well as they should guarantee a good electrical contact among the metal particles and between the catalyst and the current collector. Hence carbons should have a low electrical resistance and a suitable mesoporous high “accessible” surface area. In this paper different commercial high surface area-carbon supports were investigated and data of the electrochemical, structural and morphological characterization of carbon powders and carbon electrodes with Nafion as proton conductor binder are reported. Supported Pt-Ru catalysts were prepared by electrochemical deposition on the different carbon/Nafion electrodes, and the effect of different carbon/Nafion supports on the structure, morphology and catalytic activity during electrooxidation of methanol of the Pt-Ru deposits is discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
