Accelerating chemical reactions without direct contact with a catalyst
“Improving our understanding of the catalyst-intermediary-reaction relationship could greatly expand the possibilities of catalytic reactions,” said Harold Kung, Walter P. Murphy Professor of Chemical and Biological Engineering at the McCormick School of Engineering, who led the research. “By learning that a chemical reaction can proceed without direct contact with a catalyst, we open the door to using catalysts from earth-abundant elements to perform reactions they normally wouldn’t catalyze.”
The study, titled “Noncontact Catalysis: Initiation of Selective Ethylbenzene Oxidation by Au Cluster-Facilitated Cyclooctene Epoxidation,” was published January 31 in the journal Science Advances. Mayfair Kung, a research associate professor of chemical and biological engineering, was a co-corresponding author on the paper. Linda Broadbelt, Sarah Rebecca Roland Professor of Chemical and Biological Engineering and associate dean for research, also contributed to the study.
The research builds on previous work in which the team investigated the selective oxidation of cyclooctene—a type of hydrocarbon—using gold (Au) as a catalyst. The study revealed that the reaction was catalyzed by dissolved gold nanoclusters. Surprised, the researchers set out to investigate how well the gold clusters could catalyze selective oxidation of other hydrocarbons.
Using a platform they developed called Noncontact Catalysis System (NCCS), the researchers tested the effectiveness of a gold catalyst against ethylbenzene, an organic compound prevalent in the production of many plastics. While ethylbenzene did not undergo any reaction in the presence of the gold clusters, the team found that when the gold clusters reacted with the cyclooctene, the resulting molecule provided the necessary intermediary to produce ethylbenzene oxidation.
