This project, supported by the Analytical and Surface Chemistry Program in the Division of Chemistry, is directed by Prof. Dennis C. Johnson of the Chemistry Department at Iowa State University. The work utilizes electrochemical cells containing doped metal oxide anodes whose electrocatalytic properties will be exploited in a study of oxygen-transfer oxidations involving polar organic molecules. Oxygen atom mediation is proposed by the PI as the mechanism by which these oxidations proceed. Experiments designed to provide evidence to support or deny this mechanism will be carried out and digital simulations will be used to confirm mechanisms. Aliphatic amines, amino acids and small peptides, many with functional groups containing sulfur, are the test compounds. Working electrodes fabricated as disks suitable for the rotated disk electrode assembly are used to obtain current-voltage curves which can be analyzed for their mechanistic information. The surface topography of the electrodes is explored using the scanning electron microscope. To provide additional information to support the mechanism studies, chemical analysis of the products of exhaustive electrolysis will be done with gas chromatography-mass spectrometry and electrospray-mass spectrometry. Electrode reactions in electrochemical cells produce chemical changes in the ions or molecules which take part in the reaction but until the pathway is known by which such a change occurs, scientific use of the process is limited. The objective of this project is to understand the nature of reactions taking place at the anode of a cell which involve the transfer of an oxygen atom to form a product. There are many examples of compounds which might follow such a pathway including some of biological interest and others of environmental concern. Potential applications of the knowledge gained are found in the area of sensors for chemical analysis.
