Role of Calcination Temperature on Isosorbide Production from Sorbitol Dehydration over the Catalyst Derived from Ce(IV) Sulfate

Isosorbide is a multi-purpose chemical that can be produced from renewable resources. Specifically, it has been investigated as a replacement for toxic bisphenol A (BPA) in the production of polycarbonate (PC). In this study, the synthesis of isosorbide by sorbitol dehydration using a cerium-based catalyst derived from calcined cerium (IV) sulfate (300 degrees C, 400 degrees C, 450 degrees C, 500 degrees C, and 650 degrees C) was investigated. The reaction occurred in a high-pressure reactor containing nitrogen gas. Advanced instrumental techniques were applied to analyze the characteristics of the calcined catalyst. The results showed that the calcined catalysts demonstrated different crystalline structures and sulfate species at different temperatures. However, the acidic properties (strength and amount) of the catalyst did not change with the calcination temperature. The cerium (IV) sulfate calcined at 400 degrees C exhibited the best catalytic performance, achieving the highest isosorbide yield (55.7%) and complete conversion of sorbitol at 180 degrees C, 20 bar of N2, and 6 h using CeSO-400. The presence of a sulfate group on the catalyst was the most important factor in determining the catalytic performance of sorbitol dehydration to iso-sorbide. This work suggests that CeSO-400 catalysts may play an important role in reducing reaction conditions.