195962-50-6Relevant articles and documents
Fructose Transformations in Ethanol using Carbon Supported Polyoxometalate Acidic Solids for 5-Ethoxymethylfurfural Production
García-Bosch, Nadia,Bachiller-Baeza, Belén,Rodríguez-Ramos, Inmaculada,Guerrero-Ruiz, Antonio
, p. 3746 - 3753 (2018)
A series of carbon supported polyoxometalates have been prepared and studied as acid catalysts for the fructose dehydration. The catalytic supports, microporous activated carbon (AC, SBET=1190 m2/g) and high surface area graphite (HSAG, SBET=400 m2/g), were loaded with 15 wt% of polyoxometalates: phosphotungstic acid (TPA) or tungstosilicic acid (STA). The four resulting catalysts were tested in the fructose reaction at moderate temperature 140 °C, using water and ethanol solvents. Catalytic properties have been compared with those of an acidic resin, Amberlyst 15. As relevant findings the specific interactions of carbon supports and polyoxometalates let the inhibition of active phase lixiviation. An improved catalyst (STA-HSAG) in terms of selectivity to valuable products (ethoxymethylfurfural and ethyl levulinate) and high specific catalytic activity using ethanol as solvent has been developed. This catalyst can be reused after regeneration by washing with organic solvents.
Direct versus acetalization routes in the reaction network of catalytic HMF etherification
Lanzafame,Papanikolaou,Perathoner,Centi,Migliori,Catizzone,Aloise,Giordano
, p. 1304 - 1313 (2018/03/13)
The etherification of HMF (5-hydroxymethylfurfural) to EMF (5-(ethoxymethyl)furan-2-carbaldehyde) is studied over a series of MFI-type zeolite catalysts containing different heteroatoms (B, Fe, Al), aiming to understand the effect of different isomorph substitutions in the MFI framework on the reaction pathways of HMF conversion. The rate constants in the reaction network are determined for these different catalysts and analyzed with respect to the amount of Br?nsted and Lewis acid sites determined by FT-IR pyridine adsorption. Two different pathways of EMF formation, i.e. direct etherification and via acetalization, were evidenced. The Lewis acid sites generated from the presence of aluminum are primarily active in catalyzing direct HMF etherification to EMF, which has a rate constant about one order of magnitude lower than the etherification of the corresponding acetals. This behaviour is due to the competitive chemisorption between hydroxyl and aldehyde groups (both present in HMF) on the Lewis acid sites catalyzing the etherification. A cooperation phenomenon between Br?nsted and Lewis acid sites is observed for the HMF acetal etherification to EMF acetal. In the reactions of direct HMF acetalization and deacetalization of the EMF acetal, the turnover frequencies for Silicalite-1 and B-MFI samples are about twice those for Fe-MFI and Al-MFI samples. This is attributed to the different reactivity of strong silanol groups associated with surface defects on the external surface in Silicalite-1 and B-MFI. These sites are also responsible for the EMF-to-EOP (ethyl 4-oxopentanoate) reaction step. In the deacetalization reaction of the EMF acetal, the behavior is determined from the presence of water (product of reaction) favouring the back reaction (aldehyde formation).
Catalytic transfer hydrogenation of biomass-derived 5-hydroxymethyl furfural to the building block 2,5-bishydroxymethyl furan
Hao, Weiwei,Li, Weifeng,Tang, Xing,Zeng, Xianhai,Sun, Yong,Liu, Shijie,Lin, Lu
, p. 1080 - 1088 (2016/02/27)
An efficient process for the catalytic transfer hydrogenation of biomass-derived 5-hydroxymethyl furfural (HMF) to 2,5-bishydroxymethyl furan (BHMF) is presented using ethanol as a hydrogen donor and solvent over low-cost ZrO(OH)2. A HMF conversion of 94.1% and a DHMF selectivity of 88.9% were achieved at 423 K in 2.5 h. The fresh, spent, and regenerated catalysts were characterized comprehensively, and the OH group of ZrO(OH)2 as sites for ligand exchange with ethanol was considered to be important for the activity.
