Mechanistic insight into molecular catalysts during electrocatalytic reduction of oxygen and carbon dioxide

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The central aim of the project is the development of electrocatalysts for the reduction of oxygen and carbon dioxide and to study their structure function relationship under in-operando conditions via spectro-electrochemical methods. The catalytic systems will be based on heterodinuclear compounds, which are known as "hetero-Pacman" compounds. They are characterized by the attachment of two different metal coordination fragments to a rigid backbone so that a cooperative activation of a substrate can be achieved within the Pacman cleft. Following the synthesis and characterization of the compounds, they will be tested in first reactivity studies under homogeneous conditions. Hereupon, immobilization of the compounds on surfaces will take place to allow investigations on electrocatalytic activity. The connection of the homogeneous catalysts to the electrode surface will be achieved via different methods (i.e. anchoring units). The elucidation of the influence of the type of anchoring unit on the electron transfer properties as well as product selectivity is a sub goal of the planed work.Mechanistic investigations will play an important role for the project. The focus will be given to surface sensitive in-operando spectroscopic methods such as SERRS and SEIRA that will enable the characterization of intermediates to obtain new insights in and a better understanding of the underlying processes during the reduction of O2 and CO2, respectively. The results can be, on the one hand, compared to biological systems, and, on the other hand, lead to the development of a next generation of catalytic systems. The selective reduction of oxygen to water and carbon dioxide to carbon monoxide or formic acid will be accomplished by the right choice of metal centers, ligands and reaction conditions. The optimized catalytic systems might be interesting for an application in specially designed fuel cells.