Mechanistic Chemistry at the Atomic Level

Developing the enzymes necessary for sustainable energy sources

One of the great challenges of energy research is finding ways to efficiently store and release energy from chemical bonds. Metal-based catalysts are one means by which the making and breaking of bonds can be enabled. These can include homogeneous catalysts, heterogeneous catalysts or biological catalysts (or enzymes). Of these catalysts, nature is unsurpassed in its ability to carry out challenging chemical reactions under mild conditions. Further, nature uses earth-abundant metals to catalyze these challenging reactions, meaning that the processes are necessarily sustainable. While the utilization of enzymes in industrial processes is unlikely to be practical, by understanding how the enzymes work, one can obtain the ultimate chemistry lesson from biology and then translate these ideas to rational catalytic design. However, the work of these catalysts occurs at the atomic level and fast times scales. In order to follow these reactions, Dr. Serena DeBeer, of Cornell University and the Max Planck Institute, develops new methods using x-rays to understand mechanistic chemistry on the atomic level. With these x-ray spectroscopic methods, she and her team are able to understand how the metal active centers within the catalysts are able to activate small molecules. Because a sustainable energy economy requires a strong foundation in fundamental science, Dr. DeBeer’s research provides a step towards understanding the reactions and ultimately rationally designing catalysts based on mechanistic knowledge.

In addition to the biological processes, Dr. DeBeer also studies the industrial catalysts. In contrast to the biological enzymes, the analogous industrial processes generally require extremely harsh conditions, thus making these processes very energy intensive. The differences in the biological and industrial processes imply differences in the fundamental mechanisms by which the catalysts operate. By understanding these differences, her research aims to enable more efficient and sustainable processes.

Current research includes:

  • Splitting Nitrogen: Dr. DeBeer studies the process of splitting nitrogen. Industrially this process occurs at high temperatures and pressures using complex Fe surfaces, while biologically this process is mediated by the nitrogenase enzymes, containing an iron and molybdenum active site, which can affect this conversion at room temperature. Interestingly, chemists have yet to synthesize a homogenous catalyst that can compete with either the industrial or the biological process. Hence in Dr. DeBeer’s view, understanding the industrial and biological process on the atomic level should provide the basis for knowledge based catalytic design.

  • Methane to Methanol: Oil fracking results in large amounts of burned methane, which has a detrimental effect on our environment. Dr. DeBeer is working to understand how enzymes can be used to convert the burned methane into a usable fuel. Thus reducing the impact on the environment and increasing energy efficient utilization of resources.

  • Water Oxidation: Dr. DeBeer studies photosynthetic water oxidation processes in order to develop methods for producing hydrogen as fuel. Among the possible sources of hydrogen, water is one of the most desirable sources due to the vast and readily accessible supply. The abundance of water virtually guarantees that a hydrogen-based economy can have a practically endless supply of clean basic material for fuel production.

  • This profile is spotlighted in the Clean Energy Impact Fund.

Bio

When she was little, Dr. DeBeer enjoyed building her bug collection and planning experiments in her backyard. Although neither of Dr. DeBeer’s parents was a scientist, her pathway towards becoming a researcher was built by dedicated mentors and educators. During high school chemistry especially, she had a fantastic teacher that even let her take experiment supplies home.

Dr. DeBeer describes with excitement the moment when something comes alive in an experiment for the first time. She is also fascinated by research that is at the junction of different disciplines. For this reason, her current research is the perfect blend of all the things she really enjoys. While she is trained as a chemist, Dr. DeBeer uses the tools of high energy physics to answer fundamental questions in chemistry and biology. Therefore, her work combines both experiment and theory so that what she and her team learn in the computer is always tested by reality.

In her free time, aside from research, Dr. DeBeer is an avid cook and enjoys a regular yoga practice.

Website: http://chemistry.cornell.edu/faculty/detail.cfm?netid=sdg63

Publications

Valence-to-Core-Detected X-ray Absorption Spectroscopy: Targeting Ligand Selectivity

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Identification of a spin-coupled Mo(III) in the Nitrogenase Iron-Molybdenum Cofactor

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Experimentally Quantifying Small Molecule Bond Activation Using Valence-to-Core X-ray Emission Spectroscopy

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X-ray Emission Spectroscopy Evidences a Central Carbon in the Nitrogenase Iron-Molybdenum Cofactor

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Probing Valence Orbital Composition with Iron Kβ X-ray Emission Spectroscopy

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Awards

Alfred P. Sloan Research Fellow, 2011

Kavli Fellow, U.S. National Academy of Science, 2012

European Research Council Consolidator Grant Awardee, 2013

Society of Biological Inorganic Chemistry, Early Career Award, 2015