Tandem Catalytic Conversion of Glucose to 5-Hydroxymethylfurfural with an Immobilized Enzyme and a Solid Acid

Abstract

Conversion of cellulosic biomass to renewable chemicals such as 5-hydroxymethylfurfural (HMF) is of high current interest. Herein, we report a rare example of one-pot synthesis of HMF from glucose by tandem catalysis. The system is composed of a thermophilic glucose isomerase enzyme for glucose isomerization to fructose and a solid acid catalyst for fructose dehydration to HMF. A base (−NH 2 ) functionalized mesoporous silica (aminopropyl-FMS) with large pore size was deployed successfully to immobilize and protect the thermophilic glucose isomerase in organic solvents at high temperature. The combination of this catalyst with a Brønsted acid (−SO 3 H) functionalized mesoporous silica (propylsulfonic acid-FMS) allowed us to conduct a one-pot transformation of glucose to HMF directly in a monophasic solvent system composed of tetrahydrofuran (THF) and H 2 O (4:1 v/v) with 61% yield of fructose and 30% yield of HMF at temperatures >363 K in 24 h.