Thomas Schwartz, an assistant professor of chemical engineering at the University of Maine received a U$513,995 NSF Career Award to advance his ongoing study of the Lebedev process. To date, there has been little research carried out on the Lebedev process, the multi-step chemical reaction used to make butadiene from biomass-derived ethanol, at the molecular level.
According to Schwartz, “Synthetic rubber is used in all sorts of consumer products, from car tires to paper coatings. Our goal is to enable the production of synthetic rubber from renewable resources.”
Understanding the intricacies of the process would help researchers create new catalysts, which are necessary for the chemical reactions to make goods from both petroleum and biomass that would increase butadiene yield. The emergence of improved catalysts could help grow the development of biobased, renewable chemicals.
The new study builds on the previous research conducted by Schwartz and his UMaine Catalysis Group founded in 2015.
Hussein Abdulrazzaq, a former Ph.D. student from Schwartz’s lab who graduated last year, previously led a group of fellow scholars and researchers in a study into the first step of the Lebedev process: converting ethanol to acetaldehyde and ethylene using magnesia-silica as a catalyst. The team discovered the mechanism that converts ethanol to acetaldehyde and ethylene, becoming the first researchers to pinpoint and report it for that catalyst.
Schwartz, in his study, aims to deduce the point in the reaction at which carbon-carbon bond formation occurs. “The literature is conflicted about the (carbon-carbon) coupling mechanism and nature of the requisite active sites, which we seek to clarify,” he explains.
Testing the hypothesis will require Schwartz and his team to first identify the chemical steps in the Lebedev process influences the production of butadiene by measuring rates of the reaction using model magnesia-silica catalysts. Researchers must then use spectroscopy to characterize the model catalysts and determine the requirements for producing butadiene.
The end result of this research will be a series of molecular-level descriptions of how the reactions occur on the industrial catalysts. These kinds of descriptions are important for designing next-generation Lebedev catalysts.
While magnesia-silica is crucial in the L:Lebedev process, it is complex and produces small quantities of butadiene. Schwartz’s research will provide other scientists the information they need to create new catalysts that could be used for the process and produce more butadiene than magnesia-silica.