Synthesis of a hybrid Anderson-type polyoxometalate in deep eutectic solvents (DESs) for deep desulphurization of model diesel in ionic liquids (ILs)

A novel hybrid Anderson-type polyoxometalate, {[(CH 3 ) 3 N(CH 2 ) 2 OH] 2 }[H 0.2 K 0.2 Na 2.6 (H 2 O) 6 ][IMo 6 O 24 ] (Abbreviated as (ChO) 2 K 0.2 Na 2.6 IMo 6 ) was synthesized in a deep eutectic solvent and characterized by XRD, FT-IR, thermal analysis, electrochemical measurements and inductively-coupled plasma, atomic emission spectrometer (ICP-AES). This hybrid polyoxometalate was used as a catalyst in ionic liquids (ILs) for desulfurization of model diesel. The catalyst (ChO) 2 K 0.2 Na 2.6 IMo 6 in the extraction and catalytic oxidative desulfurization (ECODS) system, containing H 2 O 2 and 1-octyl-3-methylimidazolium tetrafluoroborate (OmimBF 4 ), displayed so high activity that the removal of DBT can reach 100% at 60   °C in 60   min. Sulfur removal for S-compounds was in the following order: DBT   >   4,6-DMDBT   >   BT. The desulfurization system shows so good stability that it can be recycled 20 times without noticeable decrease in activity.