Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment and General Theory 2011-10-27

Mechanisms and energetics for acid catalyzed β-D-glucose conversion to 5-hydroxymethylfurfurl.

Xianghong Qian

Index: J. Phys. Chem. A 115(42) , 11740-8, (2011)

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Abstract

Car-Parrinello based ab initio molecular dynamics (CPMD) coupled with metadynamics (MTD) simulations were carried out to investigate the mechanism and energetics for acid-catalyzed β-d-glucose conversion to 5-hydroxymethylfurfurl (HMF) in water. HMF is a critical intermediate for biomass conversion to biofuels. It was found that protonation of the C2-OH on glucose, the breakage of the C2-O2 bond, and the formation of the C2-O5 bond is the critical rate-limiting step for the direct glucose conversion to HMF without converting to fructose first, contrary to the wide-spread assumption in literature that fructose is the main intermediate for glucose conversion to HMF. The calculated reaction barrier of 30-35 kcal/mol appears to be solvent-induced and is in excellent agreement with experimental observations.