Hybrid Organic-Inorganic Materials Based on Polyoxometalates and Ionic Liquids and Their Application in Catalysis

Table 1

Summary of the principal reaction and hybrids applied in biphasic and heterogeneous catalysis.

Reaction	Model compound	Hybrid	References
Oxidative desulfurization	Benzothiophene (BT),; 5-methylbenzothiophenes (5-MBT); dibenzothiophenes (DBT)	Quaternary ammonium POMs complexes; [(C18H37)2N^+(CH3)2]3[PW12O40] and [(C18H37)N(CH3)3]4[H2NaPW10O40]	[49–51]
	4-6 dimethyldibenzothiophene (4,6-DMDBT) + H2O2 and real diesel
	DBT + H2O2	Surfactant type POMs [(n-C8H17)3N(CH3)3]3{PO4[XO(O)2]2} 4,; [(n-C12H25)3NCH3]3{PO4[XO(O)2]2} 4, X = Mo and W	[52, 53]
	BT, DBT, 4,6-DMDBT + H2O2	[Bmim]3[PMo12O40] (1-butyl 3-methyl imidazolium phosphomolybdate)	[54]
	BT, DBT and 4,6-DMDBT + H2O2	[Hmim]5[PMo10V2O40]	[55]
	Real diesel oil	[MIMPS]3PW12O40·2H2O (1-(3-sulfonic group) propyl-3-methyl imidazolium phosphotungstate), [Bmim]3PW12O40 (1-butyl 3-methyl imidazolium phosphotungstate), [Bmim]3PMo12O40 [Bmim]4SiW12O40.	[56]
	DBTO + H2O2	Phosphotungstic acid containing ionic liquid immobilized on magnetic mesoporous silica	[57]
Epoxidation	Olefins + H2O2	Peroxotungstate dihydroimidazolium-based hybrid on modified SiO2	[58]
	Methyl-9,10, octadecenoate + H2O2 + O2	Peroxotungstate immobilized on amphiphilic resin using the methylimidazole and imidazole based ionic liquids with different alkyl substitutes (from C6 to C12) as a linkers	[63]
	Cyclooctene + H2O2	[[n-C16H33N(CH3)3]4Na3PW11O39]; Venturello’s anion coupled with alkylimidazolium cations, heteropolytungstate-ionic liquidmodified silica magnetite particles	[72]; [77]; [78]
	Oleic acid + H2O2	Q3{PO4[WO(O2)2]4} (Q = quaternary ammonium)	[76]
Alcohols oxidation	benzyl alcohol + H2O2	H3PW12O40 on 1-(3-aminopropyl)-3-propylimidazolium bromine modified SBA 15	[59]
	Variety of benzylic alcohols + H2O2	Phosphotungstic based ionic liquid complex immobilized on mesoporous silica	[61]
	Variety of benzylic and aliphatic secondary alcohols	1-methyl-3-butylimidazolium decatungstate [bmim][W10O23]	[64]
	Benzene oxidation + O2 + ascorbic acid	[(C4H9)4N]m[XW11YO39H2O] where X = P^5+, Si^4+, Ge^4+, B^3+ and Y = Ti^4+, V^5+, Cr^3+, Mn^2+, Fe^3+, Co^2+, Ni^2+, Cu^2+, Zn^2+	[65]
	Methanol + O2	Bmim3PMo12O40 and Bmim3PW12O40	[91, 92]
Hydroxylation	Benzene + H2O2	Dicationic (dimethyl diimidazolium) PMo10V2O40^5−	[66, 67]
Esterification	Palmitic acid to biodiesel	Keggin tungstophosphate complex SO3H functionalized zwitterion	[68]
	Variety of monocarboxylic acids with monohydric alcohols	Imidazolium based [MIMPS]3PW12O40, pyridinium based-[PyPS]3PW12O40 and alkyl ammonium [TEAPS]3PW12O40	[69, 70]
Transesterification	Trimethylolpropane + various fatty acid methyl esters	Imidazolium based [MIMPS]3PW12O40, pyridinium based-[PyPS]3PW12O40, and alkyl ammonium [TEAPS]3PW12O40	[71]