Gamma-valerolactone-enabled control chemoselective conversion of glucose to 1,6-anhydroglucose over HZSM-5 zeolite

Unraveling chemoselective catalysis in the upgrading of renewable biomass-derived molecules to fine chemicals and bio-fuels is particularly challenging. Here, we report an innovative strategy for the chemocatalytic conversion of glucose into 1,6-anhydroglucose, a high-value platform molecule, in γ-valerolactone (GVL) over HZSM-5 (50) zeolite. In this case, HZSM-5 (50) zeolite exhibits remarkable shape-selective catalytic performance with a high turn-over frequency (TOF) of 201.6 h−1 and a 1,6-anhydroglucose selectivity of 95.3%. Solvent effect study from both experimental and theoretical results suggests the usage of solvent GVL is particularly beneficial for glucose diffusion into the zeolite pore channel, accelerating the isomerization-dehydration process. Kinetic behavior description of glucose transformation to 1,6-anhydroglucose is developed to monitor the process, whereas a synergistic catalytic mechanism is elucidated in detail by density functional theory calculations. Such solvent-induce and shape-selective catalytic system provides a compelling strategy for highly selective production of 1,6-anhydroglucose as a biomass platform molecule.