Orchestrating Electron and Proton Transfer for Solar Energy Conversion

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

In this project funded by the Chemical Catalysis Program of the Chemistry Division, Stefan Bernhard of Carnegie Mellon University will design, synthesize and study novel light-absorbing metal complexes combined with reduction catalysts able to generate hydrogen from water and sunlight. Coordination complexes of biologically innocuous and inexpensive first-row transition metal ions will be investigated for use as catalysts and chromophores. Strongly chelating hemi-cage and wrap-around ligand topologies that stabilize these normally labile structures will be explored. Advanced spectroscopic and electrochemical techniques will be used to understand the structure and function of these complexes and their application to water-splitting systems, and parallel photoreactors will be employed to study large numbers of candidate complexes and reaction conditions. Through a combination of these spectroscopic and synthetic methods, quantitative structure-activity relationships of photocatalytic systems will be determined. These insights will be used to further improve the robustness and reaction rate of hydrogen evolution. The solution-based chemistry of these water reduction catalysts will then be modified into scalable photoelectrochemical systems immobilized on transparent electrodes suitable for use in full water-splitting systems. The broader impacts involve training undergraduate and graduate students, hosting visiting high school teachers for summer research opportunities, teaching a course on the chemistry of chocolate, and the potential societal impact of renewable energy technology. This work will provide fundamental and applied knowledge about catalysts that generate hydrogen fuel from water and sunlight, and potentially could show how earth abundant metals can be used for such technologies. Results from this research would be important to the energy industry and to industries that manufacture commercial consumer products that require fuels sources, such as the automotive and aerospace sectors.