Rachel Getman of Clemson University has won the nation’s top award for early-career researchers and will use the $500,000 her team received to explore new ways of making a chemical that helps feed about half the world but remains out of reach in the poorest regions.
Getman, an assistant professor of chemical engineering, received the funding as part of the National Science Foundation’s Faculty Early Career Development Program.
The team’s long-term goal is to find a new way of making ammonia using water instead of hydrogen gas. Ammonia is used in commercial fertilizers to improve crop yields and has been crucial in sustaining the world’s population boom over the last century.
The current method of making ammonia, the Haber-Bosch process, was developed in 1909 and involves reacting two gases, nitrogen and hydrogen, at high temperature and pressure. It’s energy intensive and expensive.
“Agriculture has expanded significantly, but only in parts of the world that can afford the Haber-Bosch process,” Getman said. “The poorer regions of the world that can’t afford to pressurize these gases are not benefitting.”
Hydrogen gas is less than ideal as a reactant because it’s an expensive commodity that is difficult to produce, separate and store.
Meanwhile, water is plentiful and eliminates the need for high temperature and pressure in ammonia production. With water, ammonia can be formed in the same ambient conditions that are found in a typical home or office.
Some energy is still required, although not as much as is needed for the Haber-Bosch process.
“The reaction between nitrogen and water to form ammonia is endothermic, which means it’s energetically uphill,” Getman said. “That means it’s not going to happen unless energy is inputted to the system.
“We propose to do that through electrocatalysis. Energy is imparted into a catalyst. If the catalyst is a metal, it can be charged up, and the charge helps cause bonds to break and bonds to form.”