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Catalytic oxidation is considered a viable method for reducing the sulphur level of transportation fuels and H 2 O 2 is usually used as the oxidant. For this reason, it is essential that any extraction operation must remove the oxidation product from the fuel. A new oxidation method is studied in the present work. Instead of H 2 O 2 , air was used as the oxidant and phosphotungstic acid (PW) was used as the catalyst; the latter was imbedded in the pore spaces of the mesoporous silica material SBA-15 to form a PW/SBA-15 composite. The oxidation reaction occurred in the pore spaces of the composite and the polar reaction products were immediately adsorbed there. As a consequence, there was no need for a subsequent exaction operation. Desulphurization experiments were carried out using a model fuel composed of n-octane and thiophene. The content of thiophene was reduced from 2000 ppmw to less than 1 ppmw at 50°C and ambient pressure. The saturated PW/SBA-15 composite was regenerated at 350°C by using a nitrogen flow for 4 h. Such conditions allowed the catalytic activity to be recovered.