Modelling the Mechanisms of the Oxygen Reduction Reaction

Many promising new energy technologies make use of the reduction of molecular oxygen as the electrode reaction at the cathode side of a galvanic cell. This reaction involves the transfer of electrons from the electrode to the molecule and any inefficiency in this transfer reduces the efficiency of the cell. One possible cause of such an inefficiency is due to the reaction being spin-forbidden: the total spin state changes from reactant to product. This thesis has explored whether this change in spin can be overcome through a concerted two-electron transfer. To this end we construct a simple model of the oxygen molecule and the electron transfer process. We find that the concerted two-electron transfer plays no significant role in this reaction.