Synthesis and Application of Dawson-Type Vanadium Polyoxotungstate Emulsion Catalyst for Oxidative Desulfurization

Environmental pollutions originated from fossil fuel cause to consider the development of rigorous rules to remove sulfur containing compounds and achievement of novel process to follow the mentioned of rigorous rules. In this regard and for the first time, new Dawson-type vanadium polyoxotungstate emulsion catalysts, [TBA]6쓽雗xVxO62 (x= 0, 1, 3, 5) have been synthesized successfully for oxidative desulfurization of sulfur compounds and characterized by using element analysis, FTIR, 31P MAS NMR and UV-vis DRS. These catalysts were used to oxidize sulfur-containing components, dibenzothiophene and benzothiophene by using hydrogen peroxide under mild conditions ( temperature lower than 100 oC and atmospheric pressure). The activity of catalysts has been grow by increase in number of vanadium in the structure of heteropoly anion. The reactivity of sulfur compound, dibenzothiophene was much more than benzothiophene. The emulsion catalyst with the highest number of vanadium, [TBA]11P2W13V5O62, could oxidize 85 % of dibenzothiophene and 50 % benzothiophene after 75 minutes, under temperature 60 oC and by using hydrogen peroxide 30 v-% in oxygen to sulfur mole ratio 4.