Using electricity, scientists find promising new method of boosting chemical reactions

In this case, she and her team focused on the surface of the electrode that provides the electricity to the reaction.

“There were hints that the surface itself is catalytic, that it plays a role,” Wuttig said, “but we don’t know how to systematically control those interactions at the molecular level.”

They tinkered with a type of reaction that is commonly used in manufacturing chemicals for medicine, to form a bond between two carbon atoms.

According to theoretical predictions, when this reaction is performed using electricity, the yield from the reaction should be 100%—that is, all the molecules that went in are made into a single new substance. But when you actually run the reaction in the lab, the yield is lower.

The team thought the presence of the electrode was tempting some of the molecules away from where they were needed during the reaction. They found that adding a key ingredient could help: a chemical known as a Lewis acid added to the liquid solution redirected those molecules.

 “You get a near-clean reaction,” Wuttig said.

Catalyzing change

Moreover, the team was able to use special imaging techniques to watch the reactions unfold at the molecular level. “You can see that the presence of the modulator has a profound effect on the interfacial structure,” she said. “This allows us to visualize and understand what’s happening, rather than regard it as a black box.” 

This is a crucial step, Wuttig said, because it shows a path forward towards being able to not only use the electrode in chemistry, but also to predict and control its effects.

Another benefit is that the electrode can be re-used for more reactions. (In most reactions, the catalyst is dissolved in the liquid and is drained away during the purification process to get the final product).

“This is a step towards sustainable synthesis,” she said. “Moving forward, my group is very excited to use these types of concepts and strategies to map out and address other synthetic challenges.”

The first author was postdoctoral researcher Qiu-Cheng Chen; other authors on the paper were undergraduate students Sarah Kress and Rocco Molinelli.

Citation: “Interfacial tuning of electrocatalytic Ag surfaces for fragment-based electrophile coupling.” Chen, Kress, Molinelli and Wuttig, Nature Catalysis, Jan. 2, 2024.

Funding: University of Chicago, National Institutes of Health.