Controlling factors and their interplay in catalytic molecular films. A key for their optimization in the pursuit of modern energy challenges. – CATMEC

To meet rising energy demand, inexpensive and carbon-neutral energy sources must be developed. Solar-driven electrochemical splitting of water to molecular hydrogen and oxygen are small molecule transformations that hold promise as routes of storing sunlight in energy-dense chemical bonds.
Activation penalties require the help of catalysts to be operated under the form of a thin film that coats an electrode. Identifying the factors that control the functioning of such devices and understanding their interplay are required for catalyst optimization and improved performance.
Besides the catalytic reaction itself, two major controlling factors are the transport of electrons from or to the electrode to regenerate the active form of the catalyst and the transport of the substrate from the bathing solution through the film toward the catalytic centers. Protons are consumed or produced during catalysis. Proton-coupled electron transfers thus play a key role in the catalytic cycle. The transport of protons and/or the acid and basic forms of the buffer often added to the solution may therefore influence the catalytic responses. In such systems, one should consider also that the transport of electrons through the film may be coupled with the transfer of protons.
The present proposal partakes to a general program in which we plan to address the various aspects of the problems depicted above. This will be performed through the following strategy: theroretical modeling to expand our model describing stationary current-potential curve for electrocatalytic films involving a single PCET redox couple to other mechanisms; investigate characteristic aspects of the proton-electron transport; investigate the kinetic role of the buffer base and its interplay with the electrolyte ion incorporated in the film; extend the investigation to other electrocatalytic films such as Ni-OEC and Mn-OEC catalyst following the same methodology as used for Co-OEC catalyst using the theroretical modeling developed in task 1 and then end up with a rational benchmarking of metal oxide OER films; investigate, both experimentally and through modeling, the possibility to increase activity by making films with embedded electronic conductive material.