WORLD JOURNAL OF ADVANCE
HEALTHCARE RESEARCH

Ayman Mohamed Almobayed*

ABSTRACT

In the present study, vanadium-supported silica (V/SiO?) catalysts with different nominal vanadium loadings (1, 3, and 5 wt%) were prepared by a two-step procedure involving sol–gel synthesis of the silica support followed by impregnation with ammonium metavanadate (NH?VO?). The prepared materials were characterized by Fourier-transform infrared (FT-IR) spectroscopy and N? adsorption–desorption analysis. The FT-IR spectrum of V/SiO? exhibited characteristic absorption bands at approximately 1095 and 798 cm?¹, corresponding to vibrational modes of the Si–O–Si framework, together with a band at approximately 948 cm?¹ associated with vanadyl/vanadium oxide species on the silica surface. The bare SiO? exhibited a BET surface area of 340 m² g?¹, a total pore volume of 0.51 cm³ g?¹, and an average pore diameter of 6.8 nm. With increasing vanadium loading, the BET surface area decreased to 328, 230, and 226 m² g?¹ for the 1, 3, and 5 wt% V–SiO? catalysts, respectively, while the pore volumes decreased to 0.49, 0.43, and 0.42 cm³ g?¹. The corresponding average pore diameters were 6.3, 5.8, and 5.8 nm, respectively. The catalytic performance of the prepared catalysts was evaluated for the oxidative removal of dibenzothiophene (DBT) from a model fuel using H?O? as the oxidizing agent. Among the investigated catalysts, 3 wt% V–SiO? exhibited the highest catalytic activity. Under the optimum conditions of 60 °C, 60 min, 0.2 g catalyst, and an H?O?/DBT molar ratio of 6, a maximum DBT removal of 94.8% was achieved. The optimum catalyst retained 79.4% of its initial activity after four consecutive reaction cycles, indicating good stability and reusability. These results demonstrate the potential of V/SiO? as an effective heterogeneous catalyst for the oxidative removal of refractory sulfur compounds from model fuels under relatively mild conditions.

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