skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Dendritic Platinum Electrocatalysts for Fuel Cells.

Abstract

Abstract not provided.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1137263
Report Number(s):
SAND2007-1940J
523770
DOE Contract Number:
DE-AC04-94AL85000
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nature; Related Information: Proposed for publication in Nature.
Country of Publication:
United States
Language:
English

Citation Formats

Song, Yujiang, Hickner, Michael A, Dorin, Rachel M., Garcia, Robert M., Wang, Haorong, Jiang, YingBing, Li, Ping, Qiu, Yan, Challa, Sivakumar R., van Swol, Frank B., Medforth, Craig John, Miller, James E., Nwoga, Tochi, Li, Wen, and Shelnutt, John Allen. Dendritic Platinum Electrocatalysts for Fuel Cells.. United States: N. p., 2007. Web.
Song, Yujiang, Hickner, Michael A, Dorin, Rachel M., Garcia, Robert M., Wang, Haorong, Jiang, YingBing, Li, Ping, Qiu, Yan, Challa, Sivakumar R., van Swol, Frank B., Medforth, Craig John, Miller, James E., Nwoga, Tochi, Li, Wen, & Shelnutt, John Allen. Dendritic Platinum Electrocatalysts for Fuel Cells.. United States.
Song, Yujiang, Hickner, Michael A, Dorin, Rachel M., Garcia, Robert M., Wang, Haorong, Jiang, YingBing, Li, Ping, Qiu, Yan, Challa, Sivakumar R., van Swol, Frank B., Medforth, Craig John, Miller, James E., Nwoga, Tochi, Li, Wen, and Shelnutt, John Allen. Thu . "Dendritic Platinum Electrocatalysts for Fuel Cells.". United States. doi:.
@article{osti_1137263,
title = {Dendritic Platinum Electrocatalysts for Fuel Cells.},
author = {Song, Yujiang and Hickner, Michael A and Dorin, Rachel M. and Garcia, Robert M. and Wang, Haorong and Jiang, YingBing and Li, Ping and Qiu, Yan and Challa, Sivakumar R. and van Swol, Frank B. and Medforth, Craig John and Miller, James E. and Nwoga, Tochi and Li, Wen and Shelnutt, John Allen},
abstractNote = {Abstract not provided.},
doi = {},
journal = {Nature},
number = ,
volume = ,
place = {United States},
year = {Thu Mar 01 00:00:00 EST 2007},
month = {Thu Mar 01 00:00:00 EST 2007}
}
  • Carbon nanotube (CNT)-supported Pt nanoparticles catalysts have been synthesized in supercritical carbon dioxide (scCO2) using platinum (II) acetylacetonate as metal precursor. The structure of the catalysts has been characterized with transmission electron micrograph (TEM) and X-ray photoelectron spectroscopy (XPS). TEM images show that platinum particles size is in the range of 5-10nm. XPS analysis indicates the presence of zero-valence platinum. The Pt-CNT exhibited high catalytic activity both for methanol oxidation and oxygen reduction reaction. The higher catalytic activity has been attributed to the large surface area of carbon nanotubes and the decrease in the overpotential for methanol oxidation and oxygenmore » reduction reaction. Cyclic voltammetric measurements at different scan rates showed that the oxygen reduction reaction at the Pt-CNT electrode is a diffusion-controlled process. Analysis of the electrode kinetics using Tafel plot suggests that Pt-CNT from scCO2 provides a strong electrocatalytic activity for oxygen reduction reaction. For the methanol oxidation reaction, a high ratio of forward anodic peak current to reverse anodic peak current was observed at room temperature, which implies good oxidation of methanol to carbon dioxide on the Pt-CNT electrode. This work demonstrates that Pt-CNT nanocomposites synthesized in supercritical carbon dioxide are effective electrocatalysts for low-temperature fuel cells.« less
  • A Pt-tungsten oxide-based electrocatalyst has been fabricated by an inexpensive chemical route for use as an oxygen cathode in 99% phosphoric acid at 180 C. The effect of %WO{sub 3} (wt/wt) on the Pt-tungsten oxide/C-based electrode performance was studied. The electrocatalytic properties for the oxygen reduction reaction (ORR), e.g., exchange current density and mass activity of a 5% Pt-40% WO{sub 3}-based electrode were found to be twice as high as those of 10% Pt, which contains double the amount of platinum. The Tafel slope and specific activity of the two electrodes are similar. It was shown that an increase inmore » its electrochemically active surface area was the only reason for the performance of the 5% Pt-40% WO{sub 3}-based electrode. The electrocatalytic parameters of the 5% Pt-40% WO{sub 3}-based electrode for the ORR were compared to those of the 2% Pt-1% H{sub 2}WO{sub 4}-based electrode.« less
  • The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. We describe a new class of electrocatalysts for the O₂ reduction, and H₂ and methanol oxidation reactions, consisting of a monolayer of Pt deposited on a metal or alloy carbon-supported nanoparticles. These electrocatalysts show up to a 20-fold increase in Pt mass activity compared with conventional all-Pt electrocatalysts. The origin of their increased activity was identified through a combination ofmore » experimental methods, employing electrochemical and surface science techniques, X-ray absorption spectroscopy, and density functional theory calculations. The long-term tests in fuel cells demonstrated excellent stability of the anode and good stability of the cathode electrocatalysts. We also describe the stabilization of Pt electrocatalysts against dissolution under potential cycling regimes effected by a submonolayer of Au clusters deposited on Pt surfaces. These new electrocatalysts promise to alleviate some of the major problems of existing fuel cell technology.« less
  • Efficient electrocatalysts are key to effective energy conversion in fuel cells that promise to be one of the major sources of clean energy. Proton exchange membrane fuel cells (PEMFCs) are the most promising type for an early, broad application. PEMFCs comprise a membrane electrolyte sandwiched by anode- and cathode-electrocatalyst layers containing Pt. At the anode, H{sub 2} is oxidized (H{sub 2} {yields} 2H{sup +} + 2e{sup -}); protons (H{sup +}) migrate through the membrane. At the cathode, O{sub 2} is reduced; both electrons and protons are concomitantly expended (O{sub 2} + 4H{sup +} + 4e{sup -} {yields} 2H{sub 2}O). Themore » difficulties that still impede the broad application of PEMFCs are associated mainly with the slow kinetics of the O2 reduction reaction (ORR) even on Pt and its alloys, the best available electrocatalysts. Consequently, the high Pt loadings are needed to achieve useful reaction rates.« less