Bi-functional electrocatalytic systems for oxygen reduction in acid medium

Marta Ratter ,  Iwona A. Rutkowska ,  Krzysztof Miecznikowski ,  Beata Baranowska ,  Adam Lewera ,  Paweł J. Kulesza 

Warsaw University, Faculty of Chemistry, Pasteura 1, Warszawa 02-093, Poland


Modification of carbon-supported RuSex nanoparticles or cobalt porphyrin catalytic centers with ultra-thin films of tungsten oxide results in the enhancement of their catalytic properties towards electroreduction of oxygen in acid (0.5 mol dm-3 H2SO4) medium as evidenced from the positive shift of the O2 reduction potential and the higher heterogeneous rate constant. An important issue is that the metal oxide support is characterized by good electronic conductivity and proton donating properties. Further, it is reasonable to expect that not only RuSex or cobalt porphyrin centers are reactive but also tungsten oxide support is capable of promoting the reduction of the undesirable hydrogen peroxide intermediate. For example, the bifunctional activity of the WO3-modified RuSex system has been the most pronounced at rather low loadings of RuSex nanoparticles. An important issue is tolerance of the proposed systems to methanol, ethanol or acetic acid formic acid, i.e. the organic systems that may appear due to crossover in the cathode compartments of methanol or ethanol fuel cells. Further, the WO3-modified RuSex (carbon-free) samples have been immobilized on the gold electrode surface for Synchrotron X-ray Photoelectron Spectroscopy (XPS) examination. The preliminary measurements have been carried out using excitation energies in the range from 90 to 1400 eV. Such experiments allow us to comment on the electronic modification of electron core levels caused by presence of adsorbed WO3 and to determine the amounts of WO3 present on the catalyst’s surface after contacting with aqueous media. These results show that the WO3 is not only adsorbed on catalyst’s surface but it also tends to interact electronically with RuSex catalytic centers. This phenomenon may also explain the relatively good stability of WO3 on the RuSex surface.

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: must be provided.


Related papers
  1. Development of multifunctional bioelectrocatalytic films for oxidation of ethanol   
  2. Integrated carbon nanotube based mediating systems for bioelectrocatalysis: application to oxygen reduction and glucose oxidation
  3. Preparation of copper hexacyanoferrate multilayer films modified with 4-(Pyrrole-1-yl) benzoic acid on glassy carbon electrode.
  4. Development of electrocatalytic materials based on the mixed addenda Dawson heteropolyanion and conducting polymers
  5. Development of novel bioelectrocatalytic systems through controlled combination of multiwalled carbon nanotubes, redox mediators and enzymes
  6. Oxidation of glucose at nanostructured composite bioelectrocatalytic systems
  7. Application of Inorganic Redox - Conducting Solids As Charge Relays in Dye-Sensitized Solar Cell
  8. Incorporation of RuSex/C within nanostructural Ir matrices to enhance oxygen reduction
  9. Electrochemical charging of carbon nanotubes modified with polyoxometallates monolayers
  10. Enzymatic carbon nanotube based composite electrodes for dioxygen reduction
  11. Multifunctional bio-electrocatalytic systems for reduction of oxygen and hydrogen peroxide
  12. Electrocatalysis and Bioelectrocatalysis at Network Films of Metal Nanoparticles and Carbon Nanostructures
  13. Bioelectrocatalytic dioxygen reduction at carbon nanotubes – silicate composite film modified electrode
  14. Development and characterization of bioelectrocatalytic systems for oxygen reduction
  15. Activation of Methanol-Tolerant Carbon-Supported RuSex Electrocatalytic Nanoparticles Towards More Efficient Oxygen Reduction
  16. Electrocatalysis and bioelectrocatalysis and nanostructured composite films
  17. New strategies in the electroctalytic reduction of oxygen for fuel and biofuel cells
  18. Polyoxometallate-modified conducting polymer linked Pt nanoparticles as bifunctional electrocatalysts for bromate reduction
  19. Network Films of Conducting Polymer Linked and Polymeatallate Stabilized Platinum Nanoparticles

Presentation: Poster at SMCBS'2007 International Workshop, by Marta Ratter
See On-line Journal of SMCBS'2007 International Workshop

Submitted: 2007-09-27 17:48
Revised:   2009-06-07 00:48
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine