Conversion of glucose to methyl levulinate over Sn-Al-β zeolite: Role of Sn and mesoporosity

Mesoporous bifunctional Sn-Al-beta zeolite was prepared by post-synthesis method for the catalytic synthesis of methyl levulinate (MLE). Tin species were introduced to Al-beta zeolite to enhance the Lewis acidity. Hydrothermal treatment with tetraethylammonium hydroxide was applied to reconstructure the zeolite and enhance the porosity of Sn-Al-beta. The role of Lewis/Bronsted acidity and mesoporosity in the catalytic conversion of glucose to MLE was investigated. Tin species increased Lewis acidity, which promoted the isomerization of glucose to fructose. Mesoporosity was favorable for the formation of MLE. 49% yield of MLE was given over Sn-Al-beta at 180 degrees C for 5 h.