Highly selective glucose isomerization by HY zeolite in gamma-butyrolactone/H2O system over fixed bed reactor

HZSM-5, Hβ, HY and USY zeolites were applied to the isomerization of glucose. An excellent selectivity (96%) of fructose was achieved, catalyzed by HY zeolite in gamma-butyrolactone/H 2 O over the fixed bed reactor. Moreover, the glucose isomerization could be carried out for over 480 h under the optimal conditions. High density of Lewis acid (0.27 mmol·g −1 ) over HY facilitates the intramolecular C 2 → C 1 H-shift reaction over the glucopyranose ring, which is the rate-determining step during Lewis acid-catalyzed steps of the glucose isomerization. Besides, large porous structure of HY zeolite (7.4 Å) facilitates the isomerization of glucose.