603
Modeling Electrochemical Reactions - Methods, Phenomena and Problems from Metals to Oxides to Organics
or in energy conversion and storage, the reduction and evolution of this species plays a central role. In Biology, for example
iron or manganese containing enzymes efficiently cleave of form the oxygen-oxygen bond. In fuel cells, platinum aids in converting
the energy stored in hydrogen and oxygen. In electrolyzers, iridium oxide might be the catalyst of choice for oxygen evolution.
If one now considers approaches for the simulation of the electronic structure of systems like metals, oxides and enzymes, one
finds that very different approaches are applied, even different communities and schools exist - Terms like solid state physics, semiconductor
physics, quantum chemistry or bioinorganic chemistry come to mind. Is this merely a reflection of the historical process in which these
disciplines evolved, or is there an expalanation why catalytic reactions on metals are treated with a very different toolbox from the methods common
in biocatalysis ?
Im my presentation I will give an overview of the phenomena in oxygen reduction and evolution and discuss differences and similarities
of electrocatalytic reactions for metals, metal oxides and molecules. A central scheme will be the electronic structure focusing on the
availability to supply charge and spin to the active site of a catalyst. This includes discussing the question when the energies of intermediates
are sufficient to understand a catalytic reaction or if transition states need to be included. Is it sufficient to have an estimate for the density of states
in order to understand heterogenous reactions or are more details required to identify the major influences for catalysis ?
This overview, which is meant to inspire different fields to join their effords,
will be illustrated by examples from my own work on platinum nanoparticles and extended carbon structures,
by examples from our department on biocatalysis as well as examples from the literature.