Darren Dolan, Graduate Student, Voutchkova Lab, GW Department of Chemistry

The Department of Chemistry Presents, via Online and In-person Presentation: Darren Dolan, Graduate Student, Voutchkova Lab GW Department of Chemistry

Catalytic processes contribute to more than 35% ($25 trillion) of the nation’s GDP. The majority of this comes from the generation of high energy fuels or bulk platform chemicals. Although a variety of catalysts are already employed for these processes, there are several shortcomings for many of them that can be addressed such as price, difficulty of separation from final products, and recyclability among others. Here, we have optimized the synthetic process for a clay based, layered double hydroxide (hydrotalcites, HT) catalyst that is multifunctional in nature due to the ability to fine tune the particle size, morphology, and chemical speciation to a high degree. The HT may act as a catalyst on its own or act as a support for species such as palladium, ruthenium, and iridium. To date, these catalysts have shown to be highly effective for a multitude of transformations such as decarbonylation, de/hydrogenation, C-C coupling, imination/amination, isomerization, and hydrogenolysis.

Recently, we have investigated the effectiveness of HT’s to depolymerize lignin as it is an abundant biopolymer, rich in phenolic monomeric units. Lignin is notoriously difficult to selectively depolymerize because it is an asymmetric, non-repeating polymer that joins the three main monomer units through one of several different types of bonds. Consequently, a multifunctional catalyst such as HT’s is needed for this type of approach. Additionally, we have demonstrated that HT’s can be utilized to upgrade alcohols to alkanes through a series of transformations. The corresponding alkane not only has double the energy density but can be used directly in internal combustion engines. Traditionally, this type of conversion would require more than one catalyst or stoichiometric amounts of reagents, however, in this case only HT is needed. Our findings have expanded mechanistic understandings of HT’s and shown that they are effective for additional types of transformations, for which we were previously unaware.

Bio

Darren received his B.S. in Chemistry from Wilkes University in Scranton, Pennsylvania. In Fall 2019, Darren began his Ph.D. at George Washington University studying materials and catalysis. He joined, Dr. Voutchkova-Kostal’s lab in 2020 where his current research focuses on formulating new catalysts for the valorization of biomass and renewably sourced compounds to energy dense fuels and bulk platform chemicals. Darren specifically focuses on the selective depolymerization of lignin to high quality monomeric phenolic units and upgrading alcohols to more energy dense compounds such as alkanes which can be used directly as fuels in internal combustion engines. Darren has been a secondary author on two recent publications and is currently in the process of submitting a first author paper.