title: Dehydration of xylose to furfural over MCM-41-supported niobium-oxide catalysts.
abstract: A series of silica-based MCM-41-supported niobium-oxide catalysts are prepared, characterized by using XRD, N2 adsorption-desorption, X-ray photoelectron spectroscopy, Raman spectroscopy, and pyridine adsorption coupled to FTIR spectroscopy, and tested for the dehydration of D-xylose to furfural. Under the operating conditions used all materials are active in the dehydration of xylose to furfural (excluding the MCM-41 silica support). The xylose conversion increases with increasing Nb2 O5 content. At a loading of 16 wt % Nb2 O5 , 74.5 % conversion and a furfural yield of 36.5 % is achieved at 170 °C, after 180 min reaction time. Moreover, xylose conversion and furfural yield increase with the reaction time and temperature, attaining 82.8 and 46.2 %, respectively, at 190 °C and after 100 min reaction time. Notably, the presence of NaCl in the reaction medium further increases the furfural yield (59.9 % at 170 °C after 180 min reaction time). Moreover, catalyst reutilization is demonstrated by performing at least three runs with no loss of catalytic activity and without the requirement for an intermediate regeneration step. No significant niobium leaching is observed, and a relationship between the structure of the catalyst and the activity is proposed.
authors.affiliation: Departamento de Química Inorgánica, Cristalografía y Mineralogía (Unidad Asociada al ICP-CSIC), Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071 Málaga, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: García-Sancho
authors.forename: Irantzu
authors.initials: I
authors.lastname: Sádaba
authors.forename: Ramón
authors.initials: R
authors.lastname: Moreno-Tost
authors.forename: Josefa
authors.initials: J
authors.lastname: Mérida-Robles
authors.forename: José
authors.initials: J
authors.lastname: Santamaría-González
authors.forename: Manuel
authors.initials: M
authors.lastname: López-Granados
authors.forename: Pedro
authors.initials: P
authors.lastname: Maireles-Torres
mesh_terms: D002384:Catalysis; D005662:Furaldehyde / Q000737:chemistry*; D009556:Niobium / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D059027:Recycling; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014961:X-Ray Diffraction; D014994:Xylose / Q000737:chemistry*
chemical_list: C509968:MCM-41; D009556:Niobium; D012822:Silicon Dioxide; D014994:Xylose; D005662:Furaldehyde