(741a) Selective Glucose Isomerization to Fructose Using a Heterogeneous Immobilized Tertiary Amine with Tuned Molecular Design
Biomass conversion has the potential to transform our ability to produce chemicals from renewable resources. Indeed, many biomass derived compounds originate from highly functionalized molecules such as cellulose that can be hydrolyzed to produce glucose. The key challenge is converting these compounds into useful chemicals and intermediates such as 5-hydroxymethylfurfural (HMF). A key step in this process is the isomerization of glucose to fructose. Recent work identified homogeneous tertiary amines as promising catalysts with similar selectivities as Sn-Beta.4 We have immobilized tertiary amines on mesoporous silica supports. Our work has demonstrated that the design of the organosilane impacts the observed catalytic activity. Specifically, we have identified that the aminosilane should be designed to minimize amine-silanol interactions through using (1) high densities of the aminosilane on the surface, (2) a short alkyl linker, and (3) bulky substituents. We have further determined that issues associated with catalyst deactivation can be reduced through incorporating hydrophobic groups into the organosilane to minimize leaching. Overall, this work demonstrates the successful design of a selective and active catalytic material for glucose isomerization.