A Robust and Highly Selective Catalytic System of Copper–Silica Nanocomposite and 1‐Butanol in Fructose Hydrogenation to Mannitol. Issue 18 (3rd August 2020)

• Record Type: Journal Article
• Authors: Upare, Pravin P.; Hwang, Young Kyu; Kim, Jin Chul; Lee, Jeong Hyeon; Kwak, Sang Kyu; Hwang, Dong Won
• Is Part Of: ChemSusChem. Volume 13:Issue 18(2020)
• Page Start: 5050
• Page End: 5057
• Publication Date: 2020-08-03
• Subjects: 1-butanol, copper -- fructose -- hydrogenation -- nanocomposite; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202001323
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: We report for the first time the selective production of mannitol, a low‐calorie sweetener and an important pharmaceutical ingredient, from fructose using Cu−SiO2 nanocomposite as catalyst and 1‐butanol as solvent. When compared with water and ethanol, a lower fructose solubility was achieved in 1‐butanol, which caused a lower fructose conversion and higher mannitol selectivity by reducing formation of side products. Among various Cu‐based catalysts in 1‐butanol, Cu(80)−SiO2 nanocomposite gave an unprecedented mannitol (83 %) and sorbitol (15 %) yield at 120 °C, 35 bar H2, and 10 h reaction time. More importantly, this catalyst did not show any Cu leaching and its physicochemical properties were maintained after liquid‐phase fructose hydrogenation whereas other Cu‐based catalysts such as Cu(32)−Cr2 O and Cu(66)−ZnO did show significant leaching of Cu and Cr. Thus, Cu(80)−SiO2 nanocomposite and 1‐butanol are regarded as a robust and highly efficient catalytic system for the selective hydrogenation of fructose to mannitol. Also, density functional theory calculations supported that in addition to the stable initial structure of adsorbed fructose, the mannitol pathway was more thermodynamically favorable than the sorbitol pathway. Notably, the highly pure mannitol (99 %) could be recovered from the sorbitol‐containing 1‐butanol solution by simple filtration. Therefore, the present protocol is a novel and effective method to produce pure mannitol from fructose in both an environmental and an industrial context. Abstract : Mannitol Production : Cu−SiO2 nanocomposite gives an unprecedented mannitol (83 %) and sorbitol (15 %) yield by selective hydrogenation of fructose in 1‐butanol solvent as well as good stability. In addition to the stable initial structure of adsorbed fructose, the mannitol pathway is more thermodynamically favorable than the sorbitol pathway. Notably, the highly pure mannitol (99 %) can be recovered from the sorbitol‐containing 1‐butanol solution by simple filtration.