A team of University of Wisconsin-Madison chemical engineers has taken an important stride toward a greener, more selective way to steer hydrocarbon transformation into other chemicals.
Using a finely controlled electrocatalytic system, the team developed a method to break the carbon-carbon and carbon-hydrogen bonds in butane using electricity, with enough precision to steer the process toward desirable end products.
The process is early in an effort to use electricity to replace traditional chemical processing, which uses massive amounts of heat and pressure to transform petroleum and other hydrocarbons into thousands of chemicals, fuels and plastics.
Led by Marcel Schreier, an assistant professor of chemical and biological engineering at UW-Madison, and Christine Lucky (PhDChE ’24), the team published details of its advance in the journal Nature Catalysis.
Previous research established that electrocatalysis can break hydrocarbon bonds. When a hydrocarbon is added to an electrochemical cell—an electrode surrounded by an ion-rich electrolyte—and a series of different voltages is applied, it can break the hydrocarbon into fragments and less desirable end products like carbon dioxide or carbon monoxide.
The goal of the UW-Madison research was to find an electrocatalytic method to better control this end result. The team used butane as a model, adding it into an electrochemical cell. They polarized the cell’s electrode positively, relative to the electrolyte. That forced the butane to adsorb (create a thin layer) over the platinum electrode.
Using sophisticated tools, the researchers analyzed the surface chemistry and mapped how butane transformed, over time, into intermediary products as they applied different potentials. Eventually, they found a series of steps that allowed them to leave the butane adsorbed on the surface of the catalyst while also continuously producing and releasing the hydrocarbon methane.
“What we show is that we can use dynamic control over electrode potentials to initiate rearrangement of the electrochemical interface in a way that allows us to start controlling catalytic reactions, elementary step by elementary step,” says Schreier.
Refining this process will allow a level of control and efficiency that is not available in thermal catalysis—the process of using heat to break chemical bonds. “I think we need to think bigger when we start using electricity. It’s not only that we are solving a sustainability problem, but we are solving a whole reactivity problem,” says Schreier. “Because of that, we have to throw out the rulebook of thermal chemistry and start with a new electricity-driven rulebook. Now, we’re using this rulebook to build, step by step, the toolkit that allows us to do chemical synthesis in a new way.”
Marcel Schreier is the Richard H. Soit Assistant Professor. Other authors include Shengli Jiang, Chien-Rung Shih and Baldovin-DaPra Professor Victor Zavala.
The authors acknowledge support from the Arnold and Mabel Beckman Foundation through a Beckman Young Investigator Award; NSF CAREER award CBET-2338627; the UW-Madison Wisconsin Centers for Nanoscale Technology supported through the National Science Foundation-funded University of Wisconsin Materials Research Science and Engineering Center DMR-1720415; and NSF Graduate Research Fellowship Program, DGE-1747503.