A new magnetically recyclable catalyst (Fe3O4@mSiO2/NH‐PV2W) was fabricated by immobilizing divanadium‐substituted Keggin phosphotungstic acid H5PV2W10O40 on mesoporous‐silica‐coated Fe3O4 core–shell nanoparticles by a facile procedure. The magnetic core–shell nanoparticles were prepared by coating a thin mesoporous silica shell directly on pristine magnetic Fe3O4 and functionalized with amino radicals simultaneously. Then the active H5PV2W10O40 was immobilized on the mesoporous silica shell of the Fe3O4 core–shell nanoparticles. The obtained catalyst was characterized by using SEM, TEM, IR spectroscopy, XRD, N2 sorption–desorption, and magnetometry. The catalytic properties were evaluated for a series of alcohols that were oxidized selectively to the corresponding aldehydes or ketones using hydrogen peroxide as the oxidant. The results show that H5PV2W10O40‐loaded mesoporous silica‐coated Fe3O4 catalyst presents high catalytic activities with 98 % conversion of benzyl alcohol and 99 % selectivity to benzaldehyde. After the reaction, the catalyst could be separated easily with an external magnetic field, and the recovered catalyst could be reused at least five times without any loss of catalytic activity.

Sustainable solar-to-ammonia conversion under ambient conditions using air and water as feedstock is a promising approach to supply low-concentrated ammonia (fertilizer) for farms. In the present work, the semiconductor-like polyoxometalate,...

Polyoxometalates based ionic liquids (POM-ILs) exhibit a high catalytic activity in oxidative desulfurization. In this paper, four new POM-IL hybrids based on transition metal mono-substituted Keggin-type phosphomolybdates, [Bmim] 5 [PMo 11 M(H 2 O)O 39 ] (Bmim = 1-butyl 3-methyl imidazolium; M = Co 2+ , Ni 2+ , Zn 2+ , and Mn 2+ ), have been synthesized and used as catalysts for the oxidation/extractive desulfurization of model oil, in which ILs are used as the extraction solvent and H 2 O 2 as an oxidant under very mild conditions. The factors that affected the desulfurization efficiency were studied and the optimal reaction conditions were obtained. The results showed that the [Bmim] 5 [PMo 11 Co(H 2 O)O 39 ] catalyst demonstrated the best catalytic activity, with sulfur-removal of 99.8%, 85%, and 63% for dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), and benzothiophene (BT), respectively, in the case of extraction combining with a oxidative desulfurization system under optimal reaction conditions (5 mL model oil (S content 500 ppm), n(catalyst) = 4 µmol, n(H 2 O 2 )/n(Substrate) = 5, T = 50 • C for 60 min with [Omim]BF 4 (1 mL) as the extractant). The catalyst can be recycled at least 8 times, and still has stability and high catalytic activity for consecutive desulfurization. Probable reaction mechanisms have been proposed for catalytic oxidative/extractive desulfurization.because it can proceed under mild reaction conditions, and oxidized products can be easily removed by extraction with organic extractants, owing to oxidized compounds being more polar than hydrocarbon molecules [20][21][22][23][24]. Although conventional organic extractants, including acetonitrile, methanol, dimethylsulfoxide (DMSO), dimethylformamide (DMF), sulfolane, and dichloromethane, reveal good extraction, their flammable and toxic properties limit their development and application in industries.Ionic liquids (ILs), as a class of green solvents, have numerous advantages over conventional organic solvents [25,26]. In 2001, Wasserscheid et al. first reported desulfurization of diesel fuel by extraction with ionic liquids [27]. The results demonstrated that ILs have the potential to play an important role in achieving clean fuel oil. Subsequently, significant literature has become available about desulfurization systems by extraction with various ILs, such as imidazolium-based ionic liquids [28][29][30][31], pyridiniuim-based ionic liquids [32], Lewis and Brösted acidic ionic liquids, and redox ionic liquids [7,33]. However, sulfur removal using only ILs as the extractant is insufficient and hardly meets stringent environmental regulations.Thus, researchers turned towards the addition of catalysts, combining peroxides with the ILs to achieve enhancement in efficiency. H 2 O 2 is often chosen as an oxidant in oxidative desulfurization, because it only produces water as a byproduct and is environmentally benign. Polyoxometalates (POMs) have received increasing attention as oxidative catalysts, due to their characterist...