Development of Solid Acid Catalysts for Synthesis of Chemicals from Sugars and Sugar Alcohols

This review describes our efforts in the development of high-performance solid acid catalysts for synthesis of useful chemicals from sugars and sugar alcohols. We found that zeolite beta, which had both Lewis and Br & oslash;nsted acid sites, acted as effective bifunctional catalyst for one-pot synthesis of 5-hydroxymethylfurfural (HMF) from glucose. Particularly, by controlling the density of these acid sites in zeolite beta with a high density of Al atoms, a high yield of HMF over 70 % was achieved. We also developed catalysts for derivatizing furfurals into useful chemicals. We established novel synthesis methods for hafnium-containing zeolite beta and titanium suboxide fine particles, and each showed significantly high activity in transfer hydrogenation and acetalization of furfural, respectively. Furthermore, it was found that zeolites with a low density of Al atoms exhibited high activity for dehydration of sorbitol to isosorbide in water. Due to the hydrophobic nature of the solid surface, such zeolites were less likely to be deactivated by water, resulting in the high activity and high durability even under severe conditions in hot water.