Temporally and Spatially Resolved Electrochemical Infrared Spectroscopy

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Electrochemistry is of great value and importance to human activity and the global economy. For example, electrical power sources including batteries, dye-sensitized solar cells, fuels cells and supercapacitors all require electrochemical processes to generate electricity. Furthermore, many industrial practices rely on electrocatalytic transformations to manufacture valuable commodity chemicals and materials. Fundamental studies that lead to better understanding and more efficient means to perform electrochemical reactions would be of great societal benefit as it is estimated that electrochemical activities consume about 10% of the world’s electrical energy. Information pertaining to commercially important reaction mechanisms has traditionally been inferred from techniques that measure electrical characteristics (e.g. current- voltage relationships). A deficiency of using purely electrical methods to study electrochemical reactions is the lack of chemical sensitivity they provide and for this reason spectroscopy (the interaction of electromagnetic radiation with atoms and molecules) can be combined with traditional methods to gain molecular-level information. This research program seeks to learn new information about electrochemical reactions through the coupling of traditional electrochemical techniques with advanced infrared (IR) spectroscopy techniques. Our proposed research aims to create surfaces that amplify the IR signal from a very small number of molecules by many orders of magnitude so that we can measure and quantify what chemical species and reactions occur during electrochemical transformations such as the oxidation of fuels in fuel cells. For example, we are proposing to use the unique properties of IR radiation generated at Canada’s only synchrotron facility (the Canadian Light Source located in Saskatoon, SK) to follow the fate of molecules on the time scale of 1/100,000 of a second. This information is very important as the performance of electrocatalytic materials can be adversely affected by very short-lived intermediates. Identifying which intermediates exist and the distribution of the final products of electrochemical reactions will allow us to assess the performance of existing electrocatalytic materials and help design new and improved materials for more efficient electrochemical reactions.