(135g) Developing Catalyst Design Strategies for Reactions of Multifunctional Oxygenates

Design of catalysts for selective reduction of multifunctional oxygenates is an important objective for the development of biorefining processes. Improved catalysts are needed, for example, in reactions where it is desired to selectively hydrogenate a C=C function in the presence of an oxygenate function (or vice versa), or in the controlled reduction of molecules with multiple alcohol functions (polyols). A combination of surface science experiments on single crystal surfaces, density functional theory calculations, and experiments with supported technical catalysts have been carried out to investigate strategies for designing catalysts capable of selectively reducing a variety of unsaturated oxygenates and polyols. Our overall objective is to identify how adsorbed oxygenates are adsorbed on metal surfaces, how the adsorption geometry affects observed surface reactions, and how the catalyst structure may be manipulated to foster oxygenate-metal interactions that result in highly selective reactions.

In this presentation, we will describe findings from our investigations of the surface chemistry of several model oxygenates, including 2(5H)-hydrofuranone, crotonaldehyde, 1-epoxy-3-butene, ethylene glycol, and 1,2-propanediol. Preferred adsorption geometries and thermal decomposition chemistries have been identified for each of the molecules on one or more metal surfaces, and provides insights into how adsorbate structure correlates with the selectivity of reduction reactions. Two methods for designing catalysts for improved selectivity control?the use of bimetallic catalysts and of organic surface modifiers?have been explored and will be discussed in detail. Finally, this presentation will highlight how the combination of model experiments, computational chemistry tools, and reaction studies on technical catalysts can be combined to design selective catalysts for multifunctional oxygenates.