Society is increasingly aware of the carbon footprint behind many of our typical activities, whether that is driving a car powered by gasoline, turning on a light powered by electricity derived from fossil fuels, or taking a flight across the country. What we are less aware of is that there is also a carbon footprint behind most chemicals and materials that we encounter everyday – there is a carbon footprint associated even with the fabric of the clothes we wear, the food we eat, and the disinfectants we spray. We need to find ways to synthesize these chemicals and materials in a sustainable manner that eliminates the carbon footprint.
Our lab is pursuing the development of a paradigm in which carbon dioxide, nitrogen, and water molecules can be converted into a wide range of chemicals and materials using renewable electricity. These molecules act as a source of carbon, nitrogen, hydrogen, and oxygen atoms, which can be precisely assembled into more complex molecules. In essence, this means that a device which breathes air, drinks water, and takes in solar photons could someday, in principle, make many of the chemicals that we rely on. Our lab specifically looks for ways to facilitate the molecular-level dance through which chemical bonds are broken and formed, so that desired molecules can be made more selectively, efficiently, and at faster rates.
CO2 as C-atom source
Carbon-negative functionalization of molecules using carbon dioxide
Carbon dioxide is attractive for synthetic steps in which a carbon atom needs to be added. We are developing electrochemical routes for carboxylation and for converting carbon dioxide into carbon monoxide, a key chemical intermediate in the chemical industry.
N2 as N-atom source
Dissociating dinitrogen molecules for chemical synthesis
We are developing low-temperature, ambient pressure routes for the electrochemical synthesis of ammonia. At present, the Haber-Bosch process, which consumes about 1% of energy worldwide, requires hydrogen produced from steam reforming of methane, creating a large carbon footprint. We envision a sustainable route in which water is used as the hydrogen source. Electrochemically synthesized ammonia may be used in downstream chemical processes and also represents an attractive strategy for the storage of electrical energy in chemical bonds to overcome the intermittency of clean energy sources like solar and wind.
H2O as O-atom source
Transferring oxygen atoms from water to organic molecules
We are developing routes by which oxygen functionality can be introduced in saturated and unstaturated hydrocarbon feedstocks. This avoids the use of oxygen, which leads to flammability hazards with commonly used organic solvents. This reactivity can be in tandem with electrochemical C-H activation steps.