Ultra-deep Oxidative Desulfurization of Fuel Oil Catalyzed by Dawson-type Polyoxotungstate Emulsion Catalysts

Abstract

The Dawson-type polyoxotungstate emulsion catalysts Q18P2W18, Q18P2W17, and Q18P2W12 were successfully synthesized and characterized by IR and 31P MAS NMR. They were used for the oxidation of sulfur-containing compounds such as 4,6-dimethyldibenzothiophene (4,6-DMDBT), dibenzothiophene (DBT), benzothiophene (BT), and 2,5-dimethythiophene (2,5-DMT) with H2O2 as an oxidant under mild conditions. The activity of the catalysts decreased in the order: Q18P2W12 > Q18P2W17 > Q18P2W18. The oxidative reactivity of the sulfur-containing compounds decreased according to DBT > 4,6-DMDBT > BT > 2,5-DMT. BT was completely oxidized into the corresponding sulfone upon catalysis by Q18P2W12 at 60 °C for 30 min. ：合成了 Dawson 型聚氧钨酸乳液催化剂 Q18P2W18, Q18P2W17, 和 Q18P2W12. 采用红外光谱和固体核磁技术对其进行了表征, 并用于温和条件下 H2O2 氧化 4,6-二甲基二苯并噻吩 (4,6-DMDBT)、二苯并噻吩 (DBT)、苯并噻吩 (BT) 和 2,5-二甲基噻吩 (2,5-DMT) 等含硫化合物的反应中. 结果表明, 各催化剂的活性大小顺序为 Q18P2W12 > Q18P2W17 > Q18P2W18. 含硫化合物的氧化活性顺序为 DBT > 4,6-DMDBT > BT > 2,5-DMT. 在 60 °C 反应 30 min 内, Q18P2W12 催化剂能够催化氧化 BT 完全转化成相应的砜.