(476a) Hydrogenation Kinetics of Biomass-Derived Monomers over Transition Metal Catalysts: Combined First-Principles and Experimental Study

Environmental concerns regarding carbon emissions have fostered interest in the synthesis of renewable chemicals from biomass-derived feedstocks. In particular, 5-hydroxymethyl furfural (HMF) has been identified as a versatile, biomass-derived platform molecule that can be synthesized through the selective dehydration of simple sugars. Recent work has shown that HMF-acetone-HMF (HAH), derived from the aldol condensation of HMF and acetone, and its hydrogenated products result in highly functionalized monomers that enable the synthesis of performance-enhanced polyurethanes and polyester products. Importantly, by controlling the extent of hydrogenation, the chemical and physical properties of resulting monomers and subsequent polymers can be controlled. While these findings showcase an exciting opportunity for biomass-derived polymers, additional work is needed to identify catalysts and conditions necessary to maximize the yields of specific hydrogenated products. Our experimental results indicate that the hydrogenation behavior of a simpler, surrogate molecule (furfural acetone; FA) is consistent with that of the larger HAH molecule over a host of transition metal catalysts. To develop a better understanding of the surface interactions governing the hydrogenation behavior of these molecules, we have performed electronic structure calculations in conjunction with detailed reaction kinetics experiments for FA hydrogenation over copper catalysts. By combining these theoretical and experimental results we have developed a first-principles informed microkinetic model to bridge our electronic structure calculations with reaction kinetics experiments. This work yields mechanistic insight into the hydrogenation of FA (and HAH) monomers over transition metal catalysts and provides guidance towards developing improved hydrogenation catalysts.