CAS: Developing Data-Driven, Automated Methodology to Understand and Control Light-Driven Catalytic Processes

With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Stefan Bernhard of Carnegie Mellon University will study catalytic processes that are driven by light. Continued development of a sustainable society requires advances in molecular sciences that will pave the way to the solar-powered, efficient, safe and precise molecular engineering of new functional molecules, materials, and fuels.

One of the major obstacles on this path stems from the inherent difficulty of extending current chemical theories to accurately describe the complex interplay of matter and energy in light-driven chemical transformations. One of the focal points of the proposed work will be the photogeneration of hydrogen from bio-available precursors like glycerol, sugars, or cellulose.

The proposed work aims to discover new chemistries for transforming sunlight into a storable, carbon-neutral fuel. New automated and parallelized research protocols based on newly developed colorimetric hydrogen and oxygen detection methods will create significant sets of data that will be analyzed with modern artificial intelligence methodologies. Such a data-driven approach will allow a substantial acceleration of the research progress.

The newly developed tools will use modern manufacturing techniques such as 3D-printing and laser-cutting to significantly lower the cost of these setups and experiments. This approach has the potential to greatly increase the openness for exploring light-driven chemical processes. Research in the Bernhard lab will prepare students at all levels to excel in the multidisciplinary environment common in today's research, while also training them intensely in the areas of transition metal complex synthesis, photocatalysis, and data science.

The Bernhard lab involves and trains a diverse group of researchers to accomplish these research tasks. Professor Bernhard and his team will continue to be involved in outreach activities for non-scientists to educate the public on energy issues and instill excitement for science in general.

Under this award, the Bernhard research group will build on their work on the development and use of hydrogen-sensitive film to develop complementary oxygen sensitive films. These films will allow the rapid screening of the progress of hydrogen and oxygen evolving photoreactions on 96-well plates. This technique will allow the team to elaborate on earlier results on the photogeneration of hydrogen from glycerol as a source of electrons and protons, and now transition to increasingly difficult, but more desirable substrates such as monosaccharides or polysaccharides for this purpose.

The multi-well photoreactors will produce large datasets that will not only allow the optimization of reaction conditions more efficiently, but will also establish structure/activity databases that can be explored by physics-inspired machine learning approaches based on quantum mechanical calculations. These experiments will be the foundation for photochemical studies using water as the source of protons and electrons.

Gaining a full understanding and an ability to control such water oxidation processes is a requisite step toward the development of a functional water splitting system for producing hydrogen and oxygen concomitantly. The proposed work will culminate in the application of the aforementioned high throughput technology to such water photolysis systems by combining and applying the knowledge gained from the work on each half-reaction.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.