1. Could you explain the significance of your article to the non-specialist? 

Methanol is currently considered as one of the choice fuels for applications in fuel cells for consumer electronics.  Its oxidation pathways are extremely complex and if we hope to extract the most energy from it, through the 6e- oxidation to carbon dioxide, we need to understand these processes at a fundamental level.  Much research has focused on understanding the methanol oxidation pathways at polycrystalline Pt surfaces and that work has been summarized here in an attempt to provide a detailed framework for discussion of activation energies.  By obtaining values for the activation energies at specific potentials, it was determined that not only are these values potential dependent, but they are also affected by surface processes such as anion adsorption and oxide formation.  These activation energies could be used as points of comparison when investigating new Pt-based catalysts.  In addition, a detailed analysis of catalyst surface processes that affect the activation energies will help to provide a microscopic view of what is happening at an electrode surface during methanol oxidation and lead to the synthesis of catalysts ideal for methanol oxidation. 

2. What has motivated you to conduct this work? 

The platinum surface is a very dynamic one when a potential is applied.  Surface processes occurring during methanol oxidation, like oxide formation, are both potential and temperature dependent.  Determining the extent to which these surface processes affect fuel oxidation is key to the understanding of the methanol system.  Activation energies have been easily measured by electrochemists studying how fuel oxidation is enhanced as the temperature is increased.  What we had noticed was that the nature of the changing surface, as the potential and temperature were varied, was never addressed thoroughly when activation energy values were determined.  By addressing these issues, as well as drawing attention to the importance of taking these factors into account, we felt that we could provide benchmark activation energies for a polycrystalline Pt surface that could then be compared to those of other catalysts being developed.  This comparison may yield answers as to why one catalyst's performance is superior to another.

3. Where do you see this work developing in the future? 

By providing benchmark numbers for the activation energies of methanol oxidation at specific potentials, as well as calling attention to the other numerous surface processes that are not only potential, but temperature, dependent, it is our hope that a clearer understanding of the catalyst surface will be obtained.  We also look forward to more research being invested in the study of activation energies for different catalyst surfaces and the correlation of these values with specific rate determining steps in the methanol oxidation pathway.

4. Are there any particular challenges facing future research in this area? 

One of the most difficult challenges in terms of carrying out further activation energy research is the nature of the stability and reproducibility of the Pt-based electrocatalyst surface.  Many of the catalysts being developed have surfaces that change composition as the potential is varied.  Alloy surfaces are also hard to reproduce from one experiment to another.  The activation energies can only be considered useful if they are obtained on reproducible and stable surfaces.  New techniques for the accurate determination of activation energies will need to be established for other, less stable, catalyst surfaces.