Professor Daniel Nocera's research goal is to convert the U.S. energy sector's focus from fossil fuels to renewables, with a long-term goal of creating a solar fuels industry. The ample supply of solar energy can meet growing energy demands, but it is intermittent due to the daily rising and setting of the sun. A strategy to compensate for this solar cycling is to convert solar energy to carbon-containing fuels in a sustainable and scalable manner. Thus, solar energy would be harnessed in the form of chemical bonds. The basic science needed to drive such a restructuring of the U.S. energy industry begins with an understanding of how light is absorbed by molecules and then transformed into a chemical reaction - a process known as photochemistry. In this project, Dr. Nocera's group at Harvard University is developing an understanding of how to capture light energy by molecules and then productively direct the energy to drive useful chemical reactions. Dr. Nocera is actively engaged in outreach activities that introduce talented students to forefront problems in chemistry and science. He and his research team provide these students with a broad technical skill set so that they can address critical problems in their independent professional careers. Professor Nocera engages with the public to relate how chemistry can address challenges in energy and photochemistry through outreach activities in a variety of forums including national news, TV, radio programs, movies, and other public venues.
With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Nocera of Harvard University is developing a better understanding of the generation of highly energetic species that are critical to storing energy in the form of fuels. Through the interplay of spectroscopy and synthesis, new reagents, reactions and processes are created for the generation of high energy species from stable M-X (M = metal, X = halogen atom) and M-O (O = oxygen) chemical bonds. Photoactivation of M-X bonds is driven from charge transfer excited states. Ligands are crafted that have favorable secondary coordination spheres so as to allow the halogen atom to be escorted from the primary coordination sphere upon photoactivation of the M-X bond. Mechanistic studies focus of stereoelectronic factors of the ligand design that deliver the halogen atom in high yields. The photointermediates are channeled to productive and selective C-H activation and functionalization. The research also focuses on photodriven production of M-O bonds and their subsequent activation at bimetallic centers residing in novel macrocyclic ligands. A new approach for generating reactive M-O bonds by light excitation exploits pre-coordinating oxoanions to the bimetallic center. The ability of light to drive the production of an energetic metal-oxo-metal bond opens an avenue to photo-oxidize C-H bonds. Dr. Nocera is actively engaged in outreach programs with the public to convey how chemistry can address important societal challenges. His outreach activities also focus on the recruitment of female students and students from underrepresented groups. In further support of the broader impacts of the project, Dr. Nocera has developed a new undergraduate curriculum in the subject of inorganic chemistry and photochemistry.
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.
