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 V 2 O 5 reduction in an alcoholic media followed by calcination of VOHPO 4 .0.5H 2 O precursor at 400 °C. The catalysts were characterized by FT-IR spectroscopy, Raman spectroscopy, ICP-OES, X-ray diffraction (XRD), N 2 adsorption-desorption analysis, and temperature-programmed desorption (NH 3 -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 V 2 O 5 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, NH 3 -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 the highest surface area. Moreover, the catalyst reusability was examined for consecutive four times, based on which no considerable change in the catalytic activity was observed. In third project, a highly efficient process for direct transformation of xylose to butyl levulinate has been developed by a series of sulfonated mesoporous silica KIT-6. The mesoporous KIT-6 was functionalized with benzyl sulfonic acid, propyl sulfonic acid, and propyl-NH-butyl-sulfonic acid. The effect of the silica-sulfonic acid linkers was investigated as well as temperature, time, catalyst value, alcohol value, and silica type. The synthesized catalysts were characterized by FT-IR spectroscopy, X-ray diffraction, thermal gravimetric analysis, N 2 adsorption-desorption analysis, SEM, EDX, and TEM techniques. The optimum catalyst achieved BL yield of 85.5% and xylose conversion of 90.7 % in mild conditions (125 °C, 5 h). The catalyst reusability was studied for up to five cycles, and observed insignificant change in the catalytic activity