Ayman Karim, chair of the University of Virginia’s Department of Chemical Engineering, has received the 2026 ACS Catalysis Lectureship for the Advancement of Catalytic Science in Heterogeneous Catalysis for research that sheds new light on one of chemistry’s enduring mysteries: exactly how some catalysts work.
Picture this: It’s the 2026 FIFA World Cup. You see a player dribbling the ball. The very next image you see is the soccer ball in the back of the net — but you have no idea how it happened.
That’s heterogeneous catalysis in a nutshell, said Ayman Karim , the Olsen Bicentennial Professor and chair of the Department of Chemical Engineering at the University of Virginia’s School of Engineering and Applied Science.
“You have the starting molecules, the catalyst in some state — possibly with interaction with the reactant molecules — and the final product. [But] we don’t know how the catalyst enabled this transformation in detail,” Karim said.
In catalysis engineering, a specially designed material — either a “homogenous” or “heterogeneous” catalyst — is used to facilitate a chemical reaction to achieve a desired result with the least amount of waste, cost, energy or unwanted byproducts. Industrial catalysis is essential for manufacturing valuable products such as fuel or pharmaceuticals, or to reduce pollution, like automobile catalytic converters.
To improve existing catalyst designs, researchers need to understand what’s happening during reactions. That is usually easier in homogenous versus heterogeneous catalysis due to the composition of the catalysts.
In a 2023 paper , Karim and Hongliang Xin , a professor of chemical engineering at Virginia Tech, managed to break down some of the steps that happen to make heterogeneous catalytic transformations possible — sort of like seeing all the frames in that soccer game, Karim explained.
“We were able to capture snapshots of several parts of the trajectory along the reaction cycle to understand the reaction mechanism,” he said. “We show how a metal atom dynamically changes its coordination to enable the oxidation of CO to CO2 and identify specific intermediate states along the reaction cycle.”
The research was funded by the U.S. Army Research Office to advance catalysis science — fundamental knowledge that could, for example, help protect soldiers from exposure to chemical warfare agents.
The article recently won the 2026 ACS Catalysis Lectureship award , which recognizes researchers with recent, significant publications in ACS Catalysis, a journal of the American Chemical Society . This year’s winners were picked from “groundbreaking” research published in the journal over the past three years.
Karim said he feels honored to be recognized alongside pioneers in his field. Their research, by being able to capture multiple “frames,” or steps, of the reaction cycle, effectively transcended the field of heterogeneous catalysis, he said
“The work achieved something very difficult in heterogeneous catalysis that’s typically reserved to homogeneous catalysis,” Karim explained.
“Specifically, we identified the exact nature of the active site and showed that it contains specific ligands — ions or molecules that bind to a central atom or protein receptor to form a larger complex. Some ligands participate in the reaction and some are just spectators — in other words, a necessary part of the active complex, but not involved in the reaction.”
In a conversation with the journal, Karim and Xin described their research as “designing better ‘chemical matchmakers’” — materials that help molecules react faster, more selectively and with less waste.
“In simple terms, we try to understand why one atomic arrangement works better than another, so we can design cleaner and more efficient chemistry,” Karim said.
Their research is fueled by a desire to better understand catalytic behavior through electronic structure, local chemical environment, and their effect on the reaction pathways and rates.
Recent advances in catalysis, like multimodal operando characterization — watching a chemical reaction live using multiple tools like lasers, electrons or X-rays at the same time — may offer “a real chance to move beyond trial-and-error discovery,” Xin said.
The biggest challenge is that real-world catalysts are dynamic: the active site can change with temperature, pressure, reactant composition and the surrounding support environment.
“A very small change at the atomic scale can completely change the outcome of a chemical reaction,” Xin said.
It’s all in their 2023 article.
“That makes it difficult and time-consuming to define the catalyst’s true working structure and to build models that are both predictive and chemically meaningful,” Karim said.
“Solving that challenge, with multimodal operando characterization techniques and detailed kinetic studies — which track the speed, timing and step-by-step pathways of the reaction — to enable high-fidelity AI and machine learning, is exactly what will unlock the next wave of progress in heterogeneous catalysis.”
Karim and Xin will be honored for their work during ACS Fall 2026 in August in Chicago.