(14az) Designing Metal Oxide Materials for Reduction/Oxidation Reactions Based on a Fundamental Understanding of Their Behavior

The release of anthropogenic pollutants such as greenhouse gasses, agricultural and industrial waste, and incomplete treatment of waste and sewage water are increasing and therefore having larger negative impacts on the environment. Dealing with these emissions, wither by avoiding them where possible, and remediating them when avoidance is not possible, is one of the major challenges of the 21^st century. My research addresses both of these pathways through the understanding and design of metal oxide reduction/oxidation (Red/Ox) materials for solar thermochemical fuel generation and photocatalytic pollutant degradation. In solar thermochemical fuel generation concentrated solar heat is used to drive water and CO₂ splitting reactions using a metal oxide O-carrier to couple an O₂-generating half reaction to a H₂ or CO generating half reaction. The development of optimal materials is critical for this process. The metal oxide must reduce readily enough to operate at temperatures achievable with concentrated solar power(<1600°C), while not reducing so readily that it is incapable of driving the water or carbon dioxide splitting reaction. My research into solar fuels focuses on developing a fundamental understanding of what controls reducibility of metal oxides using computational chemistry (DFT) and, based on this understating, engineering of new materials with more favorable Red/Ox behavior. The computational design new materials are then verified experimentally. A seemingly different process, but fundamentally coupled research area is photocatalytic pollutant degradation. The photocatalytic remediation of pollutants is inherently a Red/Ox reaction, where a metal oxide, usually TiO₂ acts as catalysts for these reactions. My research in this area has focused on using quantum chemistry to develop a fundamental understanding the rate limiting step of this process, namely the adsorption of O₂ to the TiO₂ surface and simultaneous transfer of photo-excited electrons from the TiO₂ surface to molecular O₂. Based on this understand doping and other modification strategies for TiO₂ can be developed. In both of these cases the understanding developed can be ported to other similar processes where metal oxides facilitate RedOx processes. This includes very similar processes, such as chemical looping, or non-TiO₂photocatalysis or subjects further afield, such as solid oxide electrolysis and fuel cells, photolysis and development of catalytic converter materials. Through the research, my focus is first on a fundamental understanding of the material and its controlling processes followed by novel materials design and improvement.

Teaching Interests:

My approach to chemical engineering teaching is to convey the basics that every student needs to succeed in their careers, namely problem solving skills and a fundamental understanding of physical and chemical processes involved in chemical systems. As such I have interest in teaching at both the undergraduate and graduate levels and aim to instill a love and intuition of chemical engineering processes in the students. Of the major chemical engineering subjects, I am most interested in teaching chemical reaction engineering and transport processes at the undergraduate or graduate levels. However, I enjoy most of the chemical engineering curriculum and am happy to teach everything from basic chemistry through process design and graduate level thermodynamics. Having had the opportunity to design and teach half a semester of a masters level course on renewable fuels at ETH during my Postdoc, I am also interested in developing and teaching new graduate and undergraduate classes such as computational chemistry or renewable energy systems. I believe that the education and proper preparation of the students is the mission of a university and that this includes interactions outside of the classroom as well as within it. Therefore I plan to have an engaged research program where undergraduate as well as graduate students participate and can see the application of the subjects that they are learning about in class.