Highly efficient isomerization of glucose to fructose over Sn-doped silica nanotube

Isomerization of glucose to fructose is a fundamental and key intermediate process commonly included in the production of valuable chemicals from carbohydrates in biorefinery. Enhancement of fructose yield is a challenge. In this work, Sn-doped silica nanotube (Sn-SNT) was developed as a highly efficient Lewis acid catalyst for the selective isomerization of glucose to fructose. Over Sn-SNT, 69.1% fructose yield with 78.5% selectivity was obtained after reaction at 110 °C for 6 h. The sole presence of a large amount of Lewis acid sites in Sn-SNT without Brønsted acid site is one of the reasons for the high fructose yield and selectivity. Otherwise, high density of Si−OH groups in Sn-SNT can ensure the presence of Si−OH groups near the Sn sites, which is important for the isomerization of glucose to fructose, leading to the high fructose yield and selectivity. Furthermore, the Sn-SNT is recyclable.