16498

1748 دكتري

دكتري

شيمي آلي

اصفهان : دانشگاه صنعتي اصفهان

1399

چهارده، 100ص.: مصور ( رنگي) ، جدول، نمودار

عليرضا نجفي‌چرمهيني

مهران غياثي

عبدالرضا حاجي‌پور، صادق رستم‌نيا، محمد ديناري

1400/03/16

كتابنامه

شيمي

شيمي

1400/03/22

2696867

101 Dehydration of carbohydrates into biofuel precursors using modified mesoporous silica KIT 6 with organosulfonic acid and Vanadium Phosphate Oxide catalysts Jaleh Najafi Sarpiri March 2021 E mail jaleh najafi@ch iut ac ir Department of Chemistry Isfahan University of Technology 84156 83111 Isfahan Iran Supervisors Dr Alireza Najafi Chermahini E Mail address anajafi@cc iut ac ir Advisor Dr Mehram Ghiaci Department Graduate Coordinator Dr M Dinari Isfahan University of Technology 84156 83111 Isfahan Iran Abstract In first project the catalytic activity of a series of vanadyl pyrophosphate VPP catalysts with different loading supported on mesoporous silica KIT 6 for dehydration of glucose and fructose into 5 hydroxymethylfurfural 5 HMF was investigated The active phase was synthesized by V2O5 reduction in an alcoholic media followed by calcination of VOHPO4 0 5H2O precursor at 400 C The catalysts were characterized by FT IR spectroscopy Raman spectroscopy ICP OES X ray diffraction XRD N2 adsorption desorption analysis and temperature programmed desorption NH3 TPD techniques as well as SEM TEM and X ray photoelectron spectroscopy XPS Among the catalysts the catalyst containing the lowest percentage of VPP exhibited the best activity in the dehydration reaction The effect of different parameters such as the loading amount of VPP on the support the initial amount of carbohydrates and catalyst reaction temperature time and solvent were studied The highest yields of 5 HMF were obtained 79 145 C 1h and 48 185 C 1 5h for the fructose and glucose dehydration respectively Catalysts were simply separated via centrifugation without significant changes in catalytic activity and reused for additional four runs In second project the synthesis of well ordered mesoporous structure KIT 6 silica supported vanadyl hydrogen phosphate hemihydrate VHP KIT 6 catalysts possessing varying surface area was carried out followed by being utilized in the dehydration of sucrose to 5 hydroxymethylfurfural 5 HMF as a solid acid catalyst The fabrication of two different VHP KIT 6 catalysts was conducted using the impregnation approach through V2O5 reduction in alcoholic media Then the catalytic behavior presented by the prepared VHP KIT 6 samples was compared with unsupported VHP and unsupported vanadyl pyrophosphate VPP which was prepared through the calcination of VHP precursor at 400 C for 24h The prepared catalysts were characterized by different analyses including ICP OES BET XRD NH3 TPD analysis FT IR spectroscopy as well as SEM and TEM techniques Furthermore the effect of a variety of parameters including the catalyst type and weight sucrose amount time temperature and the type of solvent on sucrose dehydration was also studied It was observed that the highest catalytic activity in the dehydration reaction 5 HMF yield 67 sucrose conversion 94 could be provided by the catalyst possessing

عليرضا نجفي‌چرمهيني

مهران غياثي

عبدالرضا حاجي‌پور، صادق رستم‌نيا، محمد ديناري