Designing multifunctional SO₃H-based polyoxometalate catalysts for oxidative desulfurization in acid deep eutectic solvents

Abstract

Deep eutectic solvents (DESs) are ‘green’ sustainable solvents with wide applications such as extractive desulfurization of fuel; however, their low extraction efficiency is a major limitation to such applications.

A current overview of the oxidative desulfurization of fuels utilizing heat and solar light: from materials design to catalysis for clean energy

“…To date, an appreciable amount of literature has been published on the ODS of diesel fuel by utilizing POMs, chosen for their tunable properties, ample exposure of active sites and exceptional performances in redox reactions. [128][129][130][131][132][133][134][135] Typically, POMs are cluster form materials belonging to the metal oxide family, which is comprised of numerous transition metal oxoanions and oxygen atoms, frequently with heteroatoms. 136 In regard to their structure, POMs can be classified into several types, including Anderson-Evans, 134 Keggin, 133,[137][138][139] Dawson 140 and so forth, which respectively possess the coordination of a single heteroatom surrounded by 6 transition metal atoms ([XM 6 O 24 ] nÀ ), 141 one heteroatom surrounded by 12 transition metal atoms ([XM 12 O 40 ] nÀ ) 140 and two heteroatoms surrounded by 18 transition metal atoms ([X 2 M 18 O 62 ] nÀ ).…”

“…129,133,134,137,138,142 3.4.1 Homogenous POMs. In general, common homogenous Keggin-type POMs like phosphomolybdic acid (H 3 PMo 12 O 40 ), phosphotungstic acid (H 3 PW 12 O 40 ), silicotungstic acid (H 4 SiW 12 O 40 ) and sodium phosphotungstate (Na 3 PW 12 O 40 ) can be readily procured commercially.…”

Synthesis of Porous Confined Ionic Liquid Phosphotungstate Based on MIL-101 and its Solvent-Free Catalytic Oxidation of Cyclohexene to Adipic Acid

“…The bands at 1402 cm . Moreover, the typical characteristic bands of the sulfonic acid group were also found at 1260 and 1042 cm -1 [ 30 ], which were assigned to the v(S=O) asymmetric and symmetric stretching vibrations. Meanwhile, the characteristic peaks (Fig.…”

Oxidative Desulfurization of Liquid Fuels Using Polyoxometalate-Based Catalysts: A Review

“…Results indicated that the best efficiency was obtained with PEG/SSA DES under the following conditions: 20 mL of model diesel (containing 500 ppm sulfur), 4 mL of DES, 0.02 g of CrMo 6 , 1 atm O 2 , and an O 2 flow rate of 60 mL min −1 . Jiang et al 225 examined the oxidative desulfurization of DBT in model oil using 30 wt % of H 2 O 2 as an oxidant, deep eutectic solvents (DESs) as extractants, and SO 3 H-based polyoxometalate as a catalyst. The [PSTEtA] 3 PW 12 O 40 catalyst showed 100% catalytic activity for desulfurization in the presence of ChCl/2Ac as the extractant after 2.5 h. The efficiency of sulfur-compound removal followed the order of DBT > 3-MBT > 4-MDBT > 4,6-DMDBT > BT.…”

“…Jiang et al examined the oxidative desulfurization of DBT in model oil using 30 wt % of H 2 O 2 as an oxidant, deep eutectic solvents (DESs) as extractants, and SO 3 H-based polyoxometalate as a catalyst. The [PSTEtA] 3 PW 12 O 40 catalyst showed 100% catalytic activity for desulfurization in the presence of ChCl/2Ac as the extractant after 2.5 h. The efficiency of sulfur-compound removal followed the order of DBT > 3-MBT > 4-MDBT > 4,6-DMDBT > BT.…”