Understanding the Curious Selectivity toward Maleic
Anhydride during Levulinic Acid Oxidation
Dr. Jesse Bond
Sustainable Energy Studies Assistant Professor
Department of Biomedical and Chemical Engineering
Levulinic acid (LA) is an interesting bio-based chemical. Its synthesis from various lignocellulosic sugars is relatively straightforward, and its multifunctional nature opens the door to numerous downstream processing options. Unfortunately, commercial development of levulinic acid has never truly materialized. In part, this may be attributed to the fact that, despite its promise, levulinic acid upgrading has not yet allowed economically viable production of large-market commodities—e.g., levulinic acid based fuels are too expensive to compete, at present, with petroleum derivatives. In contrast, synthesis of oxygenated hydrocarbons is relatively challenging from crude oil and natural gas, and biomass may, at times, be able to provide a competitive advantage. As an example, we consider aerobic, oxidative cleavage of levulinic acid, which produces maleic anhydride (MA) in good yield. The strategy is interesting in that it connects lignocellulose, via levulinic acid, with the existing maleic anhydride market, which is robust and relatively high-value.
Oxidative cleavage of LA occurs over supported vanadates, and we have demonstrated single-pass MA yields as high as 71% of the theoretical maximum at 573K. The underlying chemistry is intriguing: oxidative ketone cleavage over supported vanadium oxides will, in general, break C-C bonds positioned internally to the ketone group, yet formation of maleic anhydride (C4) from levulinic acid (C5) requires cleavage of the terminal C-C bond. We demonstrate that monofunctional ketones, such as 2-pentanone, will preferentially cleave at internal positions; thus, this unanticipated selectivity is unique to bifunctional LA. To elucidate the mechanistic source of this disparity, we examine trends in oxidative cleavage rate and oxidative cleavage selectivity with variation in catalyst makeup and ketone structure.
Jesse Bond is an Associate Professor in the Department of Biomedical and Chemical Engineering at Syracuse University. Since 2011, his research group has focused on developing and understanding catalytic technologies for upgrading abundant natural resources, with an emphasis on liquid-phase chemistries that are of interest in biomass processing. He completed his Ph.D. at the University of Wisconsin, Madison, where he learned both the art and science of heterogeneous catalysis from Thatcher Root and Jim Dumesic. His favorite things in life are catalytic kinetics, FTIR spectra, teaching reactor design, bicycles, and—despite being a transplanted southerner— lake effect snow.
Thursday, January 31 at 2:00pm to 3:00pm
Earle Hall, 100
206 S. Palmetto Blvd., Clemson, SC 29634