title: Acid-catalyzed dehydration of fructose into 5-hydroxymethylfurfural by cellulose-derived amorphous carbon.
abstract: Carbonaceous solid (CS) catalysts with --SO₃H, --COOH, and phenolic --OH groups were prepared by incomplete hydrothermal carbonization of cellulose followed by either sulfonation with H₂SO₄ to give carbonaceous sulfonated solid (CSS) material or by both chemical activation with KOH and sulfonation to give activated carbonaceous sulfonated solid (a-CSS) material. The obtained carbon products (CS, CSS, and a-CSS) were amorphous; the CSS material had a small surface area (<0.5 m² g⁻¹) and a high --SO₃H group concentration (0.953 mmol g⁻¹), whereas the a-CSS material had a large surface area (514 m²  g ⁻¹) and a low --SO₃H group concentration (0.172 mmol g⁻¹). The prepared materials were evaluated as catalysts for the dehydration of fructose to 5-hydroxymethylfurfural (5-HMF) in the ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]). Remarkably high 5-HMF yields (83 %) could be obtained efficiently (80 °C and 10 min reaction time). CSS and a-CSS catalysts had similar catalytic activities and efficiencies for the conversion of fructose to 5-HMF in [BMIM][Cl]; this could be explained by the trade-off between --SO₃H group concentration (high for CSS) and surface area (high for a-CSS). The cellulose-derived catalysts and ionic liquid exhibited constant activity for five successive recycles, and thus, the methods developed provide a renewable strategy for biomass conversion.
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China. qixinhua@nankai.edu.cn
authors.forename: Xinhua
authors.initials: X
authors.lastname: Qi
authors.forename: Haixin
authors.initials: H
authors.lastname: Guo
authors.forename: Luyang
authors.initials: L
authors.lastname: Li
authors.forename: Richard L
authors.initials: RL
authors.lastname: Smith
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D002482:Cellulose / Q000737:chemistry*; D005632:Fructose / Q000737:chemistry*; D005662:Furaldehyde / Q000031:analogs & derivatives* / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry; D013451:Sulfonic Acids / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D052578:Ionic Liquids; D013451:Sulfonic Acids; D014867:Water; D005632:Fructose; C008046:5-hydroxymethylfurfural; D002244:Carbon; D002482:Cellulose; D005662:Furaldehyde