scholarly journals Catalytic Oxidative/Extractive Desulfurization of Model Oil using Transition Metal Substituted Phosphomolybdates-Based Ionic Liquids

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 639 ◽  
Author(s):  
Yunlei Li ◽  
Yanjie Zhang ◽  
Panfeng Wu ◽  
Caiting Feng ◽  
Ganglin Xue

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[PMo11M(H2O)O39] (Bmim = 1-butyl 3-methyl imidazolium; M = Co2+, Ni2+, Zn2+, and Mn2+), 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 H2O2 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[PMo11Co(H2O)O39] 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(H2O2)/n(Substrate) = 5, T = 50 °C for 60 min with [Omim]BF4 (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.

KIMIKA ◽  
2013 ◽  
Vol 24 (1) ◽  
pp. 2-7
Author(s):  
Harold Henrison C. Chiu ◽  
Susan D. Arco ◽  
Zhang Chun Ping ◽  
Nelson R. Villarante

The oxidative desulfurization of model oil (hexane solution of thiophene) was carried out at room temperature in a two-step method involving: 1) the acetic acid catalyzed oxidation of thiophene with hydrogen peroxide and 2) the subsequent extraction of the oxidized products with  three  1-alkyl-3-methylimidazolium  bromide  [RMIM]Br  ionic  liquids  of  varying  alkyl substituent R chain length  (R: C2, C4,  C6) and with acetonitrile as control. For purposes of comparison,  a  non-oxidative  extractive  desulfurization  of  model  oil  with  the  above  ionic liquid and with acetonitrile was also performed.  The thiophene extraction efficiencies of the ionic liquids and that of the control in both the oxidative and non-oxidative procedures were determined  by  means  of  gas  chromatography.  The  ionic  liquid  of  the  shortest  alkyl substituent chain length (R: C2), [EMIM] Br exhibited the highest extraction efficiency in the oxidative desulfurization of the model  oil; the extraction efficiency of [EMIM] Br was also observed  to  exceed  that  of  acetonitrile.  In  general,  the  oxidative  desulfurization  with  the above [RMIM]Br’s is apparently a more efficient method of thiophene removal from the model oil as compared to a non-oxidative procedure with the same extraction solvents. The extraction efficiency of [RMIM]Br’s was observed to decrease with the lengthening of the alkyl  substituent  chain.  The  same  trend  is  observed  in  the  non-oxidative  extractive desulfurization of the model oil. Recyclability analysis of [EMIM]Br showed that [EMIM]Br can be recycled thrice with no significant decrease in extraction efficiency.


NANO ◽  
2015 ◽  
Vol 10 (05) ◽  
pp. 1550075 ◽  
Author(s):  
Zhenghua Li ◽  
Heon Jong Jeong ◽  
Kumarsrinivasan Sivaranjani ◽  
Byung Jin Song ◽  
Su Bin Park ◽  
...  

Highly ordered mesoporous tungsten trioxide ( WO 3) with high surface area (75 m2/g) and well-defined mesopores were successfully prepared through a hard templating method using a mesoporous silica KIT-6 as a template and ( NH 4)6 H 2 W 12 O 40 ⋅ x H 2 O as a tungsten precursor. Oxidative desulfurization of a model oil with H 2 O 2 as the oxidant was carried out at 50°C under atmospheric pressure in order to analyze the catalytic activity. The desulfurization reactions were optimized by various kinds of reaction parameters such as H 2 O 2/ S molar ratio, reaction temperatures and series of sulfur-containing compounds [dibenzothiophene (DBT), benzothiophene (BT) and 4,6-dimethyl dibenzothiophene (4,6-DMBT)]. Excellent catalytic activity for the removal of the sulfur-containing compounds from the model oil was observed with mesoporous WO 3 catalyst, where the activity was maintained during 5 recycle tests without any regeneration process. The high catalytic activity and durability is mainly attributed to well-defined mesopores and high surface area of mesoporous WO 3 catalyst.


Author(s):  
Zhaoyang Ju ◽  
Lei Zhou ◽  
Xingmei Lu ◽  
Yao Li ◽  
Xiaoqian Yao ◽  
...  

Ionic liquids (ILs) have shown high catalytic activity in the degradation of poly (ethylene terephthalate) (PET), but the effects of anions and cations as well as the mechanism remain ambiguous....


2017 ◽  
Vol 7 (5) ◽  
pp. 1045-1049 ◽  
Author(s):  
K. Matuszek ◽  
S. Coffie ◽  
A. Chrobok ◽  
M. Swadźba-Kwaśny

Ionic liquids with Lewis superacidic borenium cations were used as catalysts in solvent-less Diels–Alder cycloaddition. The extremely high catalytic activity correlated with the Lewis acidity, expressed as the Gutmann acceptor number.


2013 ◽  
Vol 483 ◽  
pp. 38-41
Author(s):  
Shu Heng Liu

Take Waugh-Type (NH4)6[MnMo9O32] •8H2O absorbed on diatomite and prepared supported solid catalyst. The properties of the catalyst were studied through the synthesis of benzyl acetate. The appropriate reaction conditions were obtained by orthogonal test: mole ratio of acetic acid to benzyl alcohol was 2.5:1.0, the catalyst dosage was 1.6g, the water carrying agent toluene dosage was 2.5ml, reaction time was 150min, esterification yield was 87.4%. The catalyst are high catalytic activity and non- polluting, and could be reused.


Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 252 ◽  
Author(s):  
Gabriela Dobras ◽  
Kornela Kasperczyk ◽  
Sebastian Jurczyk ◽  
Beata Orlińska

N-Hydroxyphthalimide was immobilized via ester bond on commercially available silica gel (SiOCONHPI) and then coated with various ionic liquids containing dissolved CoCl2 (SiOCONHPI@CoCl2@IL). New catalysts were characterized by means of FT IR spectroscopy, elemental analysis, SEM and TGA analysis and used in ethylbenzene oxidation with oxygen under mild solvent-free conditions (80 °C, 0.1 MPa). High catalytic activity of SiOCONHPI was proved. In comparison to a non-catalytic reaction, a two-fold increase in conversion of ethylbenzene was observed (from 4.7% to 8.6%). Coating of SiOCONHPI with [bmim][OcOSO3], [bmim][Cl] and [bmim][CF3SO3] containing CoCl2 enabled to increase the catalytic activity in relation to systems in which IL and CoCl2 were added directly to reaction mixture. The highest conversion of ethylbenzene was obtained while SiOCONHPI@CoCl2@[bmim][OcOSO3] were used (12.1%). Catalysts recovery and reuse was also studied.


2014 ◽  
Vol 699 ◽  
pp. 210-214 ◽  
Author(s):  
Hayyiratul Fatimah Mohd Zaid ◽  
Chong Fai Kait ◽  
Muhammad Ibrahim Abdul Mutalib

Titanium dioxide (TiO2) photocatalyts doped with copper metal at different metal loadings were successfully prepared and characterized. Photocatalytic oxidative desulfurization of model oil containing dibenzothiophene as the sulfur compound (100 ppm) was investigated using the prepared photocatalyst. The photocatalyst with 2.0 wt% Cu metal loading showed the best sulfur removal at 66.25%.


2020 ◽  
Vol 17 (5) ◽  
pp. 1422-1431
Author(s):  
Wei Jiang ◽  
Xiang Gao ◽  
Lei Dong ◽  
Jin Xiao ◽  
Lin-Hua Zhu ◽  
...  

Abstract It is usually difficult to remove dibenzothiophenes from diesel fuels by oxidation with molecular oxygen as an oxidant. In the study, tungsten oxide was supported on magnetic mesoporous silica by calcination to form a magnetically separable catalyst for oxidative desulfurization of diesel fuel. By tuning different calcining temperatures, the catalyst calcined at 500 °C showed a high catalytic activity with molecular oxygen as the oxidant. Under optimal reaction conditions, the sulfur removal of DBT reached 99.9% at 120 °C after 8 h. Furthermore, the removals of 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene could also get up to 98.2% and 92.3% under the same conditions. The reaction mechanism was explored by selective quenching experiments and FT-IR spectra.


NANO ◽  
2020 ◽  
Vol 15 (06) ◽  
pp. 2050070
Author(s):  
Renxing Huang ◽  
Ying Lei ◽  
Dandan Zhang ◽  
Huaming Xie ◽  
Xingyong Liu ◽  
...  

Carbon encapsulated transition metal catalysts receive extensive attention in electrochemical catalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) due to the unique structure and highly adjustable electronic configuration. Herein, we synthesized 3D porous Active-N-rich graphene-like carbon layer-encapsulated Fe/Fe3C (Fe@NCG) via pyrolysis of a mixture of solvent-free assembled Fe-chitosan chelates and additional small molecule nitrogen source urea, wherein space-confinement effect of chelates suppressed agglomeration of [Formula: see text] ions and small molecule nitrogen source facilitated regulation of N configurations. The optimized catalyst Fe@NCG shows remarkable ORR/OER bifunctional catalytic activity with a half-wave potential of 0.86 V for ORR and a moderate potential difference of 0.85 V in alkaline medium. Comparative studies revealed that Active-N-rich carbon layer and inner well-dispersed Fe/Fe3C nanoparticles and the favorable interface structures between them were responsible for high catalytic activity. Excitingly, the assembled zinc-air battery with Fe@NCG catalysts exhibits a high open-circuit potential (1.45 V), extremely high peak power density (204.50[Formula: see text][Formula: see text] and energy density (814.70[Formula: see text]Wh[Formula: see text][Formula: see text]) as well as robust charge–discharge durability, surpassing those of noble metal catalyst. This proposed simple and universal strategy can also be extended to synthesize carbon encapsulated other transition metal electrocatalysts.


2014 ◽  
Vol 672-674 ◽  
pp. 613-618
Author(s):  
Feng Li Yu ◽  
Yang Lu

Heteropolyanion substituted layered double hydroxide were synthesized and used as catalysts for oxidative desulfurization in simulated fuel oil (dibenzothiophene (DBT) inn-octane) or diesel. The catalysts are recoverable and operate with high conversion efficiency under mild conditions of atmospheric pressure and 60 °C in a biphasic system using peroxide hydrogen as oxidant and acetonitrile as extractant. Zn9Al3(OH)24PW12O40(ZnAlPW), Zn9Al3(OH)24PMo12O40(ZnAlPMo) and Zn12Al4(OH)32SiW12O40(ZnAlSiW) were identified as effective catalysts for the oxidative removal of DBT from simulated fuel oil. The order of decreasing catalytic activity is ZnAlPMo > ZnAlPW > ZnAlSiW. The results show that the best catalysts, ZnAlPMo, attained to a DBT conversion of nearly 100%. All the catalysts can be readily recycled by filtration after use. The recoverable ZnAlPMo retains nearly the same catalytic activity as the fresh. ZnAlPMo was found to exhibit an ideal catalytic activity in oxidative desulfurization of diesel with a total sulfur removal rate of 91.8%.


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