While some children may find their passion by studying art or history, Ying Li, Ph.D., was fascinated by math and science in his earlier years — a zeal that has continued into the rest of his life.
Now a professor in the J. Mike Walker ’66 Department of Mechanical Engineering at Texas A&M University, Li pursued both his undergraduate and master’s degrees in thermal engineering at Zhejiang University in China.
“Although thermal engineering was not my first choice of major, it set me up for success when I went into my advanced studies,” Li said.
He buckled down and completed those degrees, soon finding his research passion in the midst of this new path.
The beginnings of a life-long research interest
When Li decided to pursue his master’s in mechanical engineering with a focus on energy and the environment, he went to the United States to accomplish it at Lehigh University.
“I knew through my research interests that I needed to expand my knowledge, and the United States is where some of the top engineering universities are where I could make that happen,” Li said.
During his master’s studies, he began research in the field of air pollution control from coal-fired power plants.
His research started with an overall study of the gases emitted when coal is burned, such as sulfur dioxide, nitrogen oxides and carbon monoxide.
Li then turned his attention to the mercury emitted as well.
“Even though the levels of mercury in coals are very low, it begins to add up when tens of tons of mercury are emitted into the atmosphere per year from all the power plants,” he explained.
When mercury is emitted and evaporated into the atmosphere and rain occurs, it gets deposited into water bodies such as lakes, rivers and oceans. This causes higher levels of water pollution.
“This in turn pollutes aquatic life such as fish that take in the mercury, which then travels up the food chain,” Li said.
His research then led to finding a way to remove mercury from the flue gas before it is emitted from the stacks of power plants.
“I developed chemical kinetic models to understand the evolution of mercury species from an elemental form to oxidized forms, and the latter are soluble, are able to be scrubbed off and then treated in wastewater,” Li said.
This research followed into his doctoral studies at the University of Florida.
“I pursued my Ph.D. in environmental engineering, with more of a focus on developing catalyst materials to boost the oxidation and capture of mercury from flue gas,” Li said.
There Li was able to gain more hands-on experience with experimental work. Following his Ph.D., Li went to Washington University in St. Louis, Missouri for post-doctoral research in chemical engineering.
“While most of my research has been on mercury emissions, I had begun to turn my attention to other emissions, and that soon led me to developing technologies to control greenhouse gases like carbon dioxide,” he said.
CO2 conversion and water treatment through solar energy
Li in his lab
After completing his post-doctoral work, Li accepted a faculty position at University of Wisconsin-Milwaukee in 2009 and then moved to Texas A&M University in 2014. Li has set his sights on how he can improve and make an impact on the environment from his lab.
Because carbon dioxide emissions from power plants make up a third of all greenhouse gas emissions, Li began to wonder how he can turn carbon dioxide, or CO2, into something useful.
“Knowing how expensive it is to capture and store CO2, I needed to rethink how to address climate change through a more innovative way,” Li said.
Instead of studying how to capture CO2, he said he began working toward using renewable energy to break down CO2.
With the knowledge that the high-energy electrons generated from renewable energy like solar and wind can break the carbon-oxygen bonds in CO2, Li aimed to create a catalyst to boost that reaction.
This research was funded by the National Science Foundation (NSF) including an NSF CAREER Award.
“Now my research has led to me developing a range of catalysts for CO2 conversion, for converting CO2 to methane, ethylene, or ethanol, depending on the market needs,” Li said.
He is also developing various processes for water purification
“Solar energy, which includes high-energy UV photons, can initiate chemical reactions that typically cannot occur at room temperature,” Li explained. “In photocatalytic water treatment, we use a catalyst to mix with contaminated water. When exposed to light, this creates electron-hole pairs, generating hydroxyl radicals. These radicals react with organic pollutants, breaking them down and mineralizing them.”
Li is also developing a synergistic solar evaporation and electrochemical treatment system that not only removes water contaminants but also provides distilled water for drinking.
Li hopes to use this process to treat wastewater and enable it to be used as purified water in rural areas without a power grid.
Advice for future researchers
In his current faculty position at Texas A&M, Li strives to help build up the next generation of researchers in this field and mentor postdocs, graduate and undergraduate students in his research lab.
He has been named a Pioneer Natural Resources Faculty Fellow III, and is also affiliated faculty in Texas A&M’s Artie McFerrin Department of Chemical Engineering. In 2023 he was named a TWRI Faculty Fellow, receiving federal funding to support his research.
“When I became interested in energy and environment, I came to know that it did not just involve one discipline,” Li said. “My research blends mechanical, chemical, environmental, and materials engineering, so it's not traditional mechanical engineering.”
Li advised that research is becoming more interdisciplinary, especially for big challenges like renewable energy, climate change and water treatment, and accordingly, students should broaden their knowledge by reading more and taking diverse courses across different engineering fields.
Learn more about Li’s research at energyenviron.tamu.edu.
