Huiyuan Zhu, an assistant professor in the Department of Chemical Engineering in the College of Engineering, received a Faculty Early Career Development (CAREER) Award to study new ways to reduce nitrate pollution in groundwater, boost agricultural production, and inspire students to tackle sustainability through careers in STEM fields.

The project will receive $592,850 over five years from the National Science Foundation and support Zhu’s research group as it focuses on the discovery of catalysts that enable efficient nitrate-to-ammonia transformation powered by renewable electricity. 

If successful, this work could lead to more environmentally beneficial and financially feasible ways to provide fertilizer for reliable food production, especially in developing countries, and help clean up nitrate pollution, Zhu said.

For the past century, the world has relied on what’s called the Haber-Bosch process to convert nitrogen into ammonia for fertilizer. That process requires natural gas, which has increased in price significantly because of the pandemic and the Russian-Ukraine war, Zhu said.

Russia and Ukraine also are major producers of fertilizers and related products, and sanctions against Russia and disruption of Ukrainian industry have caused shortages of these critical agricultural products. These shortages are expected to push up food costs worldwide, according to Morgan Stanley.

Fertilizer production and other agricultural and industrial processes also contribute to nitrate pollution, particularly in groundwater. More than half the people in the U.S. alone rely on groundwater for drinking, according to the United States Geological Survey. Nitrate, from both natural and human-caused sources, is among the most widespread contaminants in groundwater. 

Ingesting elevated levels can pose significant health risks to infants and pregnant women, according to the Centers for Disease Control and Prevention.

All these global pressures make research into sustainable and affordable methods of fertilizer production, as well as better systems to deal with nitrate pollution, especially important. Zhu’s research seeks to address these disruptions of the natural nitrogen cycle while ensuring food security.

Huiyuan Zhu
Huiyuan Zhu, assistant professor in the Department of Chemical Engineering, is working to find sustainable ways to produce nitrogen fertilizer that will increase food security in developing countries and reduce water pollution from nitrates worldwide. Photo by Tonia Moxley for Virginia Tech.

It all begins in the lab. The research team will use electrochemistry to react nitrate compounds with hydrogen derived sustainably from water to manufacture NH3, while simultaneously decomposing the nitrate pollutants and restoring balance to the nitrogen cycle.

In addition to furthering science and reducing water pollution, this new process could help developing countries gain more food security. Currently, fertilizer production “requires large infrastructure, which you cannot build everywhere,” Zhu said. “For example, if you look at sub-Saharan African countries, the transportation costs for nitrogen fertilizer are a major barrier.”

But a new, modular process powered by sustainable energy that produces less wastewater pollution could be installed on a smaller scale wherever it’s needed, she said.

“The first step to enable this reaction is to develop an active, selective, and durable electrocatalyst for this process,” Zhu said. “That’s our focus.”

The group recently published promising initial results in the online journal Nature Communications.

In addition to the research, Zhu’s group will train students from diverse groups at the interface of catalysis, chemistry, and engineering. The research will be integrated with educational and outreach efforts to illustrate the importance of sustainability in daily life, while stimulating excitement for STEM amongst K-12 youth, especially those from low-income families.

In fact, chemical engineering undergraduate Connor Hall has already been working on outreach projects in Zhu’s lab. Hall said he met Zhu through the department’s Mass and Energy Balances course.

“She had a very holistic approach and invited me to join her lab,” Hall said. “My first major project was developing a Minecraft model of sustainable ammonia production to educate youth on the benefits of green electrons and sustainable resource harvesting practices. She gave me an opportunity to present this project alongside much more scientific research about catalysis and clean energy systems.”

He went on to work with doctoral students in Zhu’s lab, where he developed a “deep understanding of catalyst synthesis methods, structural effects on selectivity/conversion, and how to learn from undesirable outcomes.

“Dr. Zhu saw my efforts and helped me attend multiple conferences,” Hall said. “In some, I was the only undergraduate in attendance among Ph.D. students, professors, and other well-respected researchers.”

Hall said working in the lab has not merely helped him gain technical knowledge, it also has given him purpose.

“The potential of our research to remove environmentally harmful industrial practices has changed my hopeful optimism,” he said. “I now feel I have a responsibility to challenge the problems of the world. I do hope to inspire more people, but more importantly, I hope to get people to participate in the change that helps the world.”

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