title: Iron oxide encapsulated by ruthenium hydroxyapatite as heterogeneous catalyst for the synthesis of 2,5-diformylfuran.
abstract: Magnetic γ-Fe2 O3 nanocrystallites encapsulated by hydroxyapatite (HAP), HAP@γ-Fe2 O3 , were prepared followed by cation exchange of Ca(2+) on the external HAP surface with Ru(3+) to give the γ-Fe2 O3 @HAP-Ru catalyst. The structure of the as-prepared catalyst was characterized, and its catalytic activity was studied in the aerobic oxidation of 5-hydroxymethylfurfural (HMF). γ-Fe2 O3 @HAP-Ru showed a high catalytic activity for the aerobic oxidation of HMF into 2,5-diformylfuran (DFF). A high DFF yield of 89.1 % with an HMF conversion of 100% was obtained after 4 h at 90 °C. Importantly, the synthesis of DFF from fructose was realized by two consecutive steps. The dehydration of fructose in the presence of a magnetic acid catalyst (Fe3 O4 @SiO2-SO3 H) produced HMF in a yield of 90.1%. Then the Fe3 O4 @SiO2 SO3 H catalyst was removed from the reaction solution with a permanent magnet, and HMF in the resulting solution was further oxidized to DFF with a yield of 79.1% based on fructose. The synthesis of DFF from fructose by two steps avoids the tedious separation of the intermediate HMF, which saves time and energy.
authors.affiliation: Key Laboratory of Catalysis and Material Sciences, State Ethnic Affairs Commission & Ministry of Education, South-Central University for Nationalities, MinYuan Road 182, Wuhan (PR China), Fax: (+86) 27-67842752. zehuizh@mail.ustc.edu.cn.
authors.forename: Zehui
authors.initials: Z
authors.lastname: Zhang
authors.forename: Ziliang
authors.initials: Z
authors.lastname: Yuan
authors.forename: Dingguo
authors.initials: D
authors.lastname: Tang
authors.forename: Yongshen
authors.initials: Y
authors.lastname: Ren
authors.forename: Kangle
authors.initials: K
authors.lastname: Lv
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
mesh_terms: D002384:Catalysis; D017886:Durapatite / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D005663:Furans / Q000138:chemical synthesis*; D017975:Ruthenium Compounds / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D005663:Furans; D017975:Ruthenium Compounds; C000499:ferric oxide; D017886:Durapatite; C476922:2,5-diformylfuran
keywords: multicomponent reactions; oxidation; renewable resources; ruthenium; supported catalysts