Managing the Nitrogen Cycle with Electrochemistry
Monday, November 30, 2020
Of the four major energy-use sectors (transportation, residential, commercial, and industrial), the industrial sector accounts for the largest amount of energy use (~32 quad/year). This energy use results in nearly 1500 million metric tons of carbon dioxide emissions yearly . The large carbon footprint is due to the fact that coal, natural gas, and petroleum are the primary energy sources utilized. With rising concerns related to global carbon emissions, there is a strong interest in displacing a majority of this hydrocarbon demand with renewable derived electricity. However, displacing hydrocarbons directly with electricity is not always feasible, prompting the need to redesign many industrial processes to enable electrification. Within the chemical commodity industry, transforming a thermocatalytic process into an electrocatalytic process is one way to increase electrification. Thermodynamically, transforming a thermocatalytic process can occur on any heterogeneous catalyst, through simply altering the surface potential of a catalyst. In practice there are many other system and catalyst related challenges which prevent electrocatalytic processes from achieving performance targets which mirror thermocatalytic systems. This inability to achieve desired performance has slowed the introduction of electrocatalytic processes in industry. The primary aim of this talk is to detail the system and materials related challenges and opportunities for electrochemical ammonia synthesis and nitrate remediation. We aim to highlight the critical targets and performance metrics which must be achieved to enable direct competition with thermocatalytic systems, and will highlight the role materials design may have in accelerating these clean technologies. Both of these reactions are critical for the growing fertilizer market place, and historically have only occurred through thermocatalytic (Haber-Bosch and Ostwald processes) or biocatalytic processes . If these processes could be accomplished electrocatalytically, this could allow for a circular nitrogen economy, which would mitigate waste and maximize food production.  U.S. Energy Information Administration, Monthly Energy Review, Table 2.1, April 2019.  Schlögl, Robert. "Catalytic Synthesis of Ammonia—A “Never‐Ending Story”?." Angewandte Chemie International Edition 42.18 (2003): 2004-2008.  Comer, Benjamin M., Porfirio Fuentes, Christian O. Dimkpa, Yu-Hsuan Liu, Carlos A. Fernandez, Pratham Arora, Matthew Realff, Upendra Singh, Marta C. Hatzell, and Andrew J. Medford. "Prospects and challenges for solar fertilizers." Joule (2019).
Marta Hatzell is an Assistant Professor of Mechanical Engineering at Georgia Institute of Technology. Prior to starting at Georgia Tech in August of 2015, she was a Post-Doctoral researcher in the Department of Material Science and Engineering at the University of Illinois - Urbana-Campaign. During her post doc, she worked in the Braun Research group on research at the interface between colloid science and electrochemistry. She completed her PhD at Penn state University in the Logan Research Group. Her PhD explored environmental technology for energy generation and water treatment. During graduate school she was an NSF and PEO Graduate Research Fellow. Currently her research group focuses on exploring the role photochemistry and electrochemistry may play in future sustainable systems. She is an active member of the American Chemical Society, the Electrochemical Society, ASEEP, AiCHE, and ASME. Dr. Hatzell has also been awarded the NSF Early CAREER award in 2019, the Alfred P. Sloan Fellowship in Chemistry in 2020, and ONR Young Investigator Award in 2020.