Deep Catalytic Oxidative Desulfurization of Model Fuel Based on

Feb 1, 2017 - Deep Catalytic Oxidative Desulfurization of Model Fuel Based on Modified ... Chinese Academy of Sciences, 27 Taoyuan South Road, Taiyuan...
0 downloads 0 Views 2MB Size
Download PDF
Letter pubs.acs.org/journal/ascecg

Deep Catalytic Oxidative Desulfurization of Model Fuel Based on Modified Iron Porphyrins in Ionic Liquids: Anionic Ligand Effect Rijie Zhao,†,‡ Jianlong Wang,*,† Dongdong Zhang,†,‡ Yahui Sun,†,‡ Baixin Han,† Nan Tang,† Jianghong Zhao,† and Kaixi Li† †

Institute of Coal Chemistry, Chinese Academy of Sciences, 27 Taoyuan South Road, Taiyuan, Shanxi 030001, P. R. China University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, P. R. China

‡

Downloaded via UNIV OF TOLEDO on June 29, 2018 at 13:46:53 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.

S Supporting Information *

ABSTRACT: The modified iron porphyrins with weak ligand (PF6−, BF4−) were prepared by a gentle and cheap approach. The catalytic systems with modified iron porphyrins and 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6) were used in the catalytic oxidative removal of sulfur compounds from model oil under mild conditions. The effect of anionic axial ligand on catalytic oxdative desulfurization performance was investigated. Iron porphyrins with weak ligand exhibited higher desulfurization performance, and the catalytic ability of catalysts was FeIIITPP(PF6) > FeIIITPP(BF4) > FeIIITPPCl. A dual active model mechanism was proposed to illustrate this phenomenon of oxidative process. The system of FeIIITPP(PF6) and [Bmim]PF6 could be recycled for 6 times without evident decrease of desulfurization efficiency. KEYWORDS: Modified iron porphyrins, Anionic ligand, Biomimetic catalysis, Desulfurization, Ionic liquids

■

INTRODUCTION Stringent regulations to limit sulfur levels in transportation fuels have been issued because of the pollution of SOx, formed during the combustion of organosulfur in transportation fuels.1,2 So, producing low-sulfur fuels has brought great challenges to current desulfurization methods and technologies.3 Hydrodesulfurization (HDS) technology has been widely used in industry and easily eliminates thiols, sulfides and disulfides. However, the conversion of dibenzothiophene (DBT) and its derivatives need very harsh conditions because of the steric hindrance.4 Therefore, nonhydrodesulfurization technologies have been developed for deep desulfurization under mild conditions. Conoco Philips Petroleum Co. developed a new effective desulfurization technique named as S-Zorb technique, combining the advantages of adsorptive desulfurization and catalytic HDS technologies.57,58 The other nonhydrodesulfurization technologies, such as oxidation, extraction, adsorption, biodesulfurization and supercritical water desulfurization are also investigated.5−10 Among of them, oxidative desulfurization (ODS) has attracted much attention due to its moderate reaction environment and high desulfurization efficiency.11−13 ODS generally goes through two stages. The sulfur compounds in fuel oil are first oxidated to corresponding sulfoxides or sulfones, then removed by extraction or adsorption.14,15 In the process of extraction, the flammability and volatilization of polar organic solvents, such as methanol, DMSO, acetonitrile and DMF, pose many environmental and security problems.16 Ionic liquids (ILs) as green solvents, have © 2017 American Chemical Society

been investigated in extraction desulfurization (EDS), because of their high thermal stability, nonvolatility, good extraction ability for aromatic sulfur compounds and immiscibility with oil.17,18 But the desulfurization yield merely extracting with ILs is low. To improve desulfurization performance, combining catalytic oxidation with ILs extraction, extractive and catalytic oxidative desulfurization (ECODS) has been proposed.19,20 In the process of ECODS, ILs play an important part in the process of extractive and oxidative sulfur compound.11,21−23 Metalloporphyrins have been widely used in solar cells, photodynamic therapy and various oxidation reactions as biomimetic models of P450s.24−27 However, metalloporphyrins have not received much attention in the desulfurization process. Especially, the effect of the anionic axial ligand on the desulfurization efficiency is not involved.28−30 It was reported that anionic axial ligands played a crucial role in the activity of iron porphyrin at the catalytic oxygenation reactions. Nam et al. reported anionic ligands effect on iron porphyrin complexcatalyzed competitive epoxidations of cis- and trans-stilbenes by various terminal oxidants.31 The ratios of cis- to trans-stilbene oxide products formed in competitive epoxidations were markedly dependent on the nature of the anionic ligands. Reed et al. reported an approach for preparing iron porphyrin by AgX (X = PF6, BF4) metathesis with mesotetraphenylporphyrinatoiron in boiling furanidine.32 In this Received: December 1, 2016 Revised: January 30, 2017 Published: February 1, 2017 2050

DOI: 10.1021/acssuschemeng.6b02916 ACS Sustainable Chem. Eng. 2017, 5, 2050−2055

Letter

ACS Sustainable Chemistry & Engineering work, we developed a gentle and cheap approach to prepare the iron porphyrins (FeIIITPPX, X = PF6, BF4) by metathesis with FeIIITPPCl. Then, biomimetic catalytic oxidative desulfurization process was investigated, in which iron porphyrins (FeIIITPPX, X = Cl, PF6, BF4, Scheme S1) were employed as catalyst, [Bmim]PF6 as exractant and H2O2 as oxidant. The metathesis of anionic axial ligands caused great influence on the desulfurization efficiency and improved the H2O2 utilization. Furthermore, the possible mechanism of oxidation of sulfurcontaining compounds was proposed, and the effect of axial ligands on the formation of the active intermediates was discussed.

■

Table 1. Effect of Different Desulfurization Systems on DBT Removal Sulfur removal /% Run 1 2 3 4

Catalyst III

Fe TPPCl FeIIITPP(BF4) FeIIITPP(PF6)

Catalyst+H2O2a

Catalyst+H2O2+ILb

1.8 1.7 1.9

93.2 98.8 99.5

ILc

28.5 −1

Model oil, sulfur content, 500 μg mL , 5 mL; reaction temperature, 60 °C; reaction time, 4 h; O/S (the molar ratio of H2O2 and sulfur) = 3:1; S/C (molar ratio of sulfur and catalyst) = 100:1. bModel oil, sulfur content, 500 μg mL−1, 5 mL; IL ([Bmim]PF6), 2 mL; reaction temperature, 60 °C; reaction time, 4 h; O/S = 3:1; S/C = 100:1. c Model oil, sulfur content, 500 μg mL−1, 5 mL; IL ([Bmim]PF6), 2 mL; reaction temperature, 60 °C; reaction time, 4 h. a

EXPERIMENTAL SECTION

Preparation of Modified Iron Porphyrins. The FeIII porphyrin (FeIIITPPCl) was synthesized following the method of Adler.49,50 Then, the preparation of iron porphyrin complexes (FeIIITPPX, X = PF6, BF4) was described as follows: in a 50 mL round-bottomed flask, 0.1 mmol FeIIITPPCl and 15 mL dichloromethane were placed in turn, then a 5 mL solution of NH4PF6 (0.25 mmol) was added. The mixture was vigorously stirred at room temperature for 15 h. After reaction, the upper solution was removed by separating funnel, and then the dichloromethane was removed by evaporation under reduced pressure. The product was directly purified by chromatography on silica gel and then by recrystallization. The yield of FeIIITPP(PF6) was 85%. FeIIITPP(BF4) was prepared with NH4BF4 in a similar manner, and the yield was 83%. The complex was characterized by using FT-IR spectra and Elemental analysis (Figure S1). Desulfurization of Model Oil. Model oil was prepared by dissolving benzothiophene (BT) or DBT or 4,6-dimethyldibenzothiophene (4,6-DMDBT) in n-octane giving a corresponding sulfur concentration of 500 μg mL−1, separately. The mixture, containing 5 mL of model oil, 2 mL of [Bmim]PF6, iron porphyrins catalyst (S/C = 100) and 24 μL of 30 wt % H2O2, was stirred vigorously at 60 °C for 4 h. The upper phase (model oil) was periodically sampled and analyzed by gas chromatography, coupled with a flame photometric detection (GC-FPD). (A 30 m × 0.25 mm inner diameter × 0.33 mm film thickness Se-30 capillary column was used for separation. Analysis conditions were as follows: injection temperature, 280 °C; detector temperature, 250 °C; oven temperature, 240 °C). The oxidative product of DBT was detected by gas chromatography−mass spectroscopy (GC−MS, Agilent 7890A GC coupled with an Agilent 5975C MSD). The electron paramagnetic resonance (EPR) signals were recorded at 100 K on a Bruker EMXPLUS-10/12 spectrometer. The 5,5-dimethyl-l-pyrroline N-oxide (DMPO) spin trap was used to detect radical intermediate in the experiments. The settings are as follows: modulation amplitude, 4.0 G; microwave frequency, 9.43 GHz; modulation frequency, 100 kHz.

The desulfurization property of systems with [Bmim]PF6, H2O2, and catalysts suggested that the catalytic ability of catalysts was FeIIITPP(PF6) > FeIIITPP(BF4) > FeIIITPPCl, which was related to the strength of anionic ligand.33 Meanwhile, the oxidative product, DBTO2 was separated and confirmed by GC−MS (Figure S2). The effect of the dosage of H2O2 was investigated with the system of FeIIITPP(PF6) and [Bmim]PF6 at 60 °C. The removal of DBT was similar at 60 °C in 1 h, when the O/S was 2:1, 2.5:1, 3:1, due to the domination of extraction with [Bmim]PF6. One molar DBT is stoichiometrically oxidized to DBTO2 with 2 molars H2O2 consumption. As shown in Figure 1, the removal of DBT could

Figure 1. Effect of different molar ratios of O and S on DBT removal. (Conditions: Model oil, sulfur content, 500 μg mL−1, 5 mL; [Bmim]PF6, 2 mL; reaction temperature, 60 °C; catalyst, FeIIITPP(PF6), S/C = 100:1).

■

RESULTS AND DISCUSSION Iron porphyrins containing different axial ligands were prepared in a gentle and cheap approach, and investigated on the performance of DBT removal in model oil (Table 1). The catalysts without IL showed no evident removal of DBT. The removal of DBT for only extraction by [Bmim]PF6 was 28.5%. Whereas the removal of DBT increased sharply with the addition of proper quantities of [Bmim]PF6. Other ILs were also investigated in the experiments, but the results were not as evident as that of [Bmim]PF6 (Table S1). So [Bmim]PF6 was employed as extractant in the following research. The systems of different catalysts and [Bmim]PF6 achieved different efficiencies of desulfurization. The desulfurization ratio was lower in terms of the iron porphyrin with a strong ligand, Cl−. But the DBT removal could be 99.5% and 98.8%, concerning iron porphyrins with ligand, PF6− and BF4−, respectively.

reach 90.6%, 96.0%, 99.5% at 60 °C in 4 h, when the O/S was 2:1, 2.5:1, 3:1, respectively. These results show that the system of FeIIITPP(PF6) and [Bmim]PF6 is effective in the oxidation of DBT under mild conditions with high availability of H2O2. Table 2 shows a comparison of the availability of H2O2 used in different desulfurization systems. Remarkably, the modified iron porphyrins system showed outstanding H2O2 utilization in removal of sulfur compound from model fuel under mild conditions. Different sulfur compounds in model oil were further investigated for different catalysts (Figure 2). The sulfur removal of different desulfurization systems unambiguously showed that the activity order of the catalysts was FeIIITPP(PF6) > FeIIITPP(BF4) > FeIIITPPCl, for different sulfur 2051

DOI: 10.1021/acssuschemeng.6b02916 ACS Sustainable Chem. Eng. 2017, 5, 2050−2055

Letter

ACS Sustainable Chemistry & Engineering Table 2. Desufurization Efficiency of Different Catalytic Systems

a

Vmodel oil/Vextractant

Entry

Catalyst Systems

Extractants

1 2 3 4 5 6 7 8 9 10 11 12 13

IL+ anhydrous FeCl3 [Bmim]Cl/FeCl3 [pmim]FeCl4-MCM-41 [BPy][FeCl4] [C4mpip]FeCl4 Fe(TF4NMe2PP)Cl [C18H37N(CH3)3]4[H2SeIV3W6O34] LaW10 ChCl/p-TsOH IL/G-h-BN FeIIITPP(PF6) FeIIITPP(BF4) FeIIITPPCl

[Bmim]BF4 [Bmim]Cl [Omim]BF4 [BPy][FeCl4] [C8mim]BF4 ethanol CH3CN [Bmim]BF4 [(C6H13)3PC14H29]2W6O19 [Bmim]PF6 [Bmim]PF6 [Bmim]PF6

5:2 3:1a 5:1 5:1 2:0.75 20:1 5:1 0.5:1a 5:2 5:2 5:2

O/S

S Removal (%)

References

6 3 5 8 3.5 6 2 5 0.05:1b 4 3 3 3

96.1 99.2 91.6 95.3 97.1 84.4 99.1 100 99.99 99.3 99.5 98.8 93.2

23 51 52 53 20 29 54 55 44 56 This work This work This work

The mass ratio of model oil and extractant. bThe mass ratio of H2O2 and model oil

exhibited a higher extraction efficiency in [Bmim]PF6, which was the same as the previous reports.34 4,6-DMDBT showed a lowest extraction efficiency because of the steric effect of methyl. Nevertheless, the overall desulfurization efficiency of the three sulfur-containing compounds was DBT > 4,6DMDBT > BT after coupling with catalytic oxidative reaction. This phenomenon was closely linked to the electron density on sulfur atoms and steric effect of sulfur-containing compounds.35,36 The process and mechanism is of great importance for understanding extractive and biomimetic catalytic oxidative desulfurization process. And the anionic axial ligand effect on the desulfurization efficiency was illustrated (Scheme 1). A triphasic system was formed because the immiscibility among the oil, H2O2 and [Bmim]PF6. The DBT in model oil was extracted into the IL phase, and oxidized to DBTO2. The oil phase was detected with GC-FPD, and did not contain DBTO2 (Figure S3). As shown in Scheme 1, the role of [Bmim]PF6 was very important in the catalytic oxidation of sulfur compounds. The anion of [Bmim]PF6 facilitated the formation and stability of [(Porp)FeIII]+.37 The structure of [Bmim]PF6 was investigated via semi-empirical, ab inito calculation, and the H-bonding of

Figure 2. Sulfur removal of different sulfur compounds from the model oil via only extraction step (the darker part of the bar) and the ECODS process (the entire bar) for three catalysts. (Conditions: Model oil, sulfur content, 500 μg mL−1, 5 mL; [Bmim]PF6, 2 mL; reaction temperature, 60 °C; O/S = 3:1; S/C = 100:1, reaction time, 4 h).

compounds. The tendency for removal of BT, DBT, 4,6DMDBT was similar for the three iron porphyrin complexes. In Figure 2 (initial extraction step, the darker part of the bar), BT Scheme 1. Proposed Mechanism of Oxidative DBT

2052

DOI: 10.1021/acssuschemeng.6b02916 ACS Sustainable Chem. Eng. 2017, 5, 2050−2055

Letter

ACS Sustainable Chemistry & Engineering

of sulfur compound, as the hydroxylation of alkanes and epoxidation reactions catalyzed by iron(III) porphyrins.47,48 Currently, the widely accepted active intermediates for oxidation of sulfur compounds are iron(III) hydroperoxide porphyrin complex ([(Porp)FeIII−OOH]) or high-valent iron(IV) oxo-porphyrin cation radical intermediates ([(Porp)]FeIV(O)]+•).40−42 But both of them played a crucial role in the oxidation of sulfur-containing compound reported herein. So, a dual active model was proposed in the oxidation of DBT to corresponding sulfone, involving the system with iron porphyrin complex and ionic liquids, using H2O2 as oxidant in Scheme 1. The desulfurization system with FeIIITPP(PF6) could be recovered and recycled. The stability of catalytic system after regeneration could be illustrated by Figure 4. After each circle,

C-2 proton of the imidazolium cation with F of the anion was postulated to exist.38 When iron porphyrin complex was added to the [Bmim]PF6, the H-bonding of C-2 with the anionic axial ligand would weaken the interaction between the Fe and anionic axial ligand.37,39 Different anionic axial ligands showed different interaction with the center metal, Fe. In general, the interaction of Fe with Cl− is stronger than that of PF6− or BF4−. The latter two anions are regarded as weak ligand. Therefore, the formation of [(Porp)FeIII]+ was easier than Cl− when the anionic axial ligand was PF6− or BF4−. That was possible reason why the system with FeIIITPP(PF6) or FeIIITPP(BF4) showed a higher desulfurization efficiency than the system with FeIIITPPCl. Then the active intermediate, [(Porp)FeIII−OOH], formed in the reaction of [(Porp)FeIII]+ and H2O2. DBT could be oxidized by active intermediate, [(Porp)FeIII−OOH].40 In the meanwhile, [(Porp)FeIV(O)]+• would be formed when H2O left from [(Porp)FeIII−OOH]. The [(Porp)]FeIV(O)]+• also participated in the oxidation of DBT to DBTO2, besides reaction with H2O2 forming H2O and O2.41,42 This side reaction could result in the nonproductive decomposition of H2O2 mentioned above. As shown in Figure 3, EPR spectra

Figure 4. Recycling of desulfurization system for removing DBT from model oil. (Conditions: Model oil, sulfur content, 500 μg mL−1, 5 mL; [Bmim]PF6, 2 mL; reaction temperature, 60 °C; reaction time, 4 h; O/ S = 3:1; catalyst, FeIIITPP(PF6), S/C = 100:1).

the upper oil phase was separated from IL by decantation, and then the IL phase was reused in the next recycle after dealing with rotatory evaporator at 60 °C. The fresh H2O2 and model oil were added under the same conditions. After 6 runs, the desulfurization efficiency of the system showed no evident decrease. Such a result indicates that no evident degradation of FeIIITPP(PF6) occurs throughout the ODS process. The desulfurization system with FeIIITPP(PF6) and [Bmim]PF6 showed outstanding performance in desulfurization of model oil. The performance of this catalytic system in practical diesel fuel (560 μg mL−1) was also investigated. Considering the complex composition of practical diesel fuel, the experiments of desulfurization of practical diesel fuel was carried out under O/S = 5, 60 °C, 2 mL of [Bmim]PF6, S/C = 100, reaction time of 4 h. The desulfurization efficiency in the practical diesel fuel was 59.3%, because part of oxidation products could not be extracted completely by [Bmim]PF6. Then the oxidized practical diesel fuel was extracted with DMF to remove the oxidized sulfur compounds. After twice extraction with equivoluminal DMF under room temperature, 96.6% of sulfurs in practical diesel fuel was removed.

Figure 3. EPR spectra of the “FeIIITPPX+[Bmim]PF6” in CH3CN after sequential addition of H2O2 and DMPO, (a) Cl−; (b) PF6−; (c) BF4−. Experimental conditions: 100 K; modulation amplitude, 4.0 G; modulation frequency, 100 kHz; microwave frequency, 9.43 GHz.

were used to detect the intermediates in these systems. The EPR spectra showed similar signals for the three systems, and a reasonable hypothesis would be made that the active intermediates formed in the oxidation of sulfur compounds maybe the same for the catalysts mentioned. The signals of g = 4.3 and g = 2.0 were observed clearly, and assigned to FeIII, S = 5/2 with rhombic distortion and a radical signal, respectively.43 The radical signal g = 2.0 indicated the presence of porphyrin πcation radical, which was different from the DMPO·OH and DMPOX.44,45 The FeIV+ of [(Porp)]FeIV(O)]+• has spin S = 1, and weakly couples to a spin S′ = 1/2 porphyrin radical.46 So, the two active intermediates were considered in the oxidation

■

CONCLUSION In summary, a gentle and cheap approach of preparing iron porphyrins containing different axial ligands was reported. we investigated the effect of different anionic axial ligands of iron porphyrins on the desulfurization efficiency. The iron porphyrins with weak ligands showed a better performance in 2053

DOI: 10.1021/acssuschemeng.6b02916 ACS Sustainable Chem. Eng. 2017, 5, 2050−2055

Letter

ACS Sustainable Chemistry & Engineering

(9) Bhatia, S.; Sharma, D. K. Biodesulfurization of dibenzothiophene, its alkylated derivatives and crude oil by a newly isolated strain Pantoea agglomerans D23W3. Biochem. Eng. J. 2010, 50, 104−109. (10) Zhu, W. S.; Zhu, G. P.; Li, H. M.; Chao, Y. H.; Chang, Y. H.; Chen, G. Y.; Han, C. R. Oxidative desulfurization of fuel catalyzed by metal-based surfactant-type ionic liquids. J. Mol. Catal. A: Chem. 2011, 347, 8−14. (11) Zhao, D. S.; Wang, J. L.; Zhou, E. P. Oxidative desulfurization of diesel fuel using a Brønsted acid room temperature ionic liquid in the presence of H2O2. Green Chem. 2007, 9, 1219−1222. (12) Cedeno, C. L.; Navarro, J. F.; Gutierrez-Alejandre, A. Oxidative desulfurization of synthetic diesel using supported catalysts: Part II. Effect of oxidant and nitrogen-compounds on extraction−oxidation process. Catal. Today 2006, 116, 562−568. (13) Xiao, J.; Wu, L. M.; Wu, Y.; Liu, B.; Dai, L.; Li, Z.; Xia, Q. B.; Xi, H. X. Effect of gasoline composition on oxidative desulfurization using a phosphotungstic acid/activated carbon catalyst with hydrogen peroxide. Appl. Energy 2014, 113, 78−85. (14) Wang, J. L.; Zhao, D. S.; Li, K. X. Oxidative Desulfurization of Dibenzothiophene Using Ozone and Hydrogen Peroxide in Ionic Liquid. Energy Fuels 2010, 24, 2527−2529. (15) Li, C.; Jiang, Z. X.; Gao, J. B.; Yang, Y. X.; Wang, S. J.; Tian, F. P.; Sun, F. X.; Sun, X. P.; Ying, P. L.; Han, C. R. Ultra-deep desulfurization of diesel: Oxidation with a recoverable catalyst assembled in emulsion. Chem. - Eur. J. 2004, 10, 2277−2280. (16) Hallett, J. P.; Welton, T. Room-Temperature Ionic Liquids: Solvents for Synthesis and Catalysis. 2. Chem. Rev. 2011, 111, 3508− 3576. (17) Kulkarni, P. S.; Afonso, C. A. M. Deep desulfurization of diesel fuel using ionic liquids: current status and future challenges. Green Chem. 2010, 12, 1139−1149. (18) Plechkova, N. V.; Seddon, K. R. Applications of ionic liquids in the chemical industry. Chem. Soc. Rev. 2008, 37, 123−150. (19) Lo, W. H.; Yang, H. Y.; Wei, G. T. One-pot desulfurization of light oils by chemical oxidation and solvent extraction with room temperature ionic liquids. Green Chem. 2003, 5, 639−642. (20) Jiang, W.; Zhu, W. S.; Chang, Y. H.; Chao, Y. H.; Yin, S.; Liu, H.; Zhu, F. X.; Li, H. M. Ionic liquid extraction and catalytic oxidative desulfurization of fuels using dialkylpiperidinium tetrachloroferrates catalysts. Chem. Eng. J. 2014, 250, 48−54. (21) Xu, D.; Zhu, W. S.; Li, H. M.; Zhang, J. D.; Zou, F.; Shi, H.; Yan, Y. S. Oxidative Desulfurization of Fuels Catalyzed by V2O5 in Ionic Liquids at Room Temperature. Energy Fuels 2009, 23, 5929−5933. (22) Wang, J. L.; Guo, Q. P.; Zhang, C. M.; Li, K. X. One-pot extractive and oxidative desulfurization of liquid fuels with molecular oxygen in ionic liquids. RSC Adv. 2014, 4, 59885−59889. (23) Zhang, J. D.; Zhu, W. S.; Li, H. M.; Jiang, W.; Jiang, Y. Q.; Huang, W. L.; Yan, Y. S. Deep oxidative desulfurization of fuels by Fenton-like reagent in ionic liquids. Green Chem. 2009, 11, 1801− 1807. (24) Mathew, S.; Yella, A.; Gao, P.; Humphry-Baker, R.; Curchod, B. F. E.; Ashari-Astani, N.; Tavernelli, I.; Rothlisberger, U.; Nazeeruddin, Md. K.; Graetzel, M. Dye-sensitized solar cells with 13% efficiency achieved through the molecular engineering of porphyrin sensitizers. Nat. Chem. 2014, 6, 242−247. (25) Celli, J. P.; Spring, B. Q.; Rizvi, I.; Evans, C. L.; Samkoe, K. S.; Verma, S.; Pogue, B. W.; Hasan, T. Imaging and Photodynamic Therapy: Mechanisms, Monitoring, and Optimization. Chem. Rev. 2010, 110, 2795−2838. (26) Meunier, B. Metalloporphyrins as Versatile Catalysts for Oxidation Reactions and Oxidative DNA Cleavage. Chem. Rev. 1992, 92, 1411−1456. (27) Che, C. M.; Huang, J. S. Metalloporphyrin-based oxidation systems: from biomimetic reactions to application in organic synthesis. Chem. Commun. 2009, 27, 3996−4015. (28) Zhou, X. R.; Lv, S.; Wang, H.; Wang, X. N.; Liu, J. H. Catalytic oxygenation of dibenzothiophenes to sulfones based on FeIII porphyrin complex. Appl. Catal., A 2011, 396, 101−106.

the desulfurization process of model oil, and the catalytic ability of catalysts was FeIIITPP(PF6) > FeIIITPP(BF4) > FeIIITPPCl. A dual active model mechanism was proposed to illustrate this phenomenon of oxidative sulfur compounds. The catalysts were stable in [Bmim]PF6, which could be recycled for six times without loss of catalytic activity. This biomimetic catalytic system is promising in the desulfurization of fuel oil, and the reactivity of catalyst could be tuned by the anionic axial ligand.

■

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acssuschemeng.6b02916. FT-IR spectra and elemental analysis of modified iron porphyrins; GC−MS spectrogram of the oxidized productions of DBT; sulfur specific of GC-FPD chromatograms for the extractive and biomimetic catalytic oxidative desulfurization of model oil; stability of catalytic system after regeneration (PDF)

■

AUTHOR INFORMATION

Corresponding Author

*Jianlong Wang. E-mail: [email protected]. ORCID

Jianlong Wang: 0000-0002-4726-8544 Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS The authors are grateful for financial supported by the National Natural Science Foundation of China (No. 21276265 and 21006122), Shanxi Province Science Foundation for Youths (No. 2010021007-1).

■

REFERENCES

(1) Samokhvalov, A. Desulfurization of Real and Model Liquid Fuels Using Light: Photocatalysis and Photochemistry. Catal. Rev.: Sci. Eng. 2012, 54, 281−343. (2) Tang, N. F.; Zhang, Y. N.; Lin, F.; Lü, H. Y.; Jiang, Z. X.; Li, C. Oxidation of dibenzothiophene catalyzed by [C 8 H 1 7 N(CH3)3]3H3V10O28 using molecular oxygen as oxidant. Chem. Commun. 2012, 48, 11647−11649. (3) Song, C. S. An overview of new approaches to deep desulfurization for ultra-clean gasoline, diesel fuel and jet fuel. Catal. Today 2003, 86, 211−263. (4) Lü, H. Y.; Li, P. C.; Deng, C. L.; Ren, W. Z.; Wang, S. N.; Liu, P.; Zhang, H. Deep catalytic oxidative desulfurization (ODS) of dibenzothiophene (DBT) with oxalate-based deep eutectic solvents (DESs). Chem. Commun. 2015, 51, 10703−10706. (5) Wang, J. L.; Zhao, R. J.; Han, B. X.; Tang, N.; Li, K. X. Extractive and oxidative desulfurization of model oil in polyethylene glycol. RSC Adv. 2016, 6, 35071−35075. (6) Li, F. T.; Liu, Y.; Sun, Z. M.; Chen, L. J.; Zhao, D. S.; Liu, R. H.; Kou, C. G. Deep Extractive Desulfurization of Gasoline with xEt3NHCl·FeCl3 Ionic Liquids. Energy Fuels 2010, 24, 4285−4289. (7) Seredych, M.; Bandosz, T. J. Removal of dibenzothiophenes from model diesel fuel on sulfur rich activated carbons. Appl. Catal., B 2011, 106, 133−141. (8) Ates, A.; Azimi, G.; Choi, K. H.; Green, W. H.; Timko, M. T. The role of catalyst in supercritical water desulfurization. Appl. Catal., B 2014, 147, 144−155. 2054

DOI: 10.1021/acssuschemeng.6b02916 ACS Sustainable Chem. Eng. 2017, 5, 2050−2055

Letter

ACS Sustainable Chemistry & Engineering (29) Pires, S. M. G.; Simoes, M. M. Q.; Santos, I. C. M. S.; Rebelo, S. L. H.; Paz, F. A. A.; Neves, M. G. P. M. S.; Cavaleiro, J. A. S. Oxidation of organosulfur compounds using an iron(III)porphyrin complex: An environmentally safe and efficient approach. Appl. Catal., B 2014, 160, 80−88. (30) Aguiar, A.; Ribeiro, S.; Silva, A. M. N.; Cunha-Silva, L.; de Castro, B.; Silva, A. M. G.; Balula, S. S. An efficient eco-sustainable oxidative desulfurization process using μ-oxo-bridged Fe(III) complex of meso-tetrakis(pentafluorophenyl)porphyrin. Appl. Catal., A 2014, 478, 267−274. (31) Nam, W.; Jin, S. W.; Lim, M. H.; Ryu, J. Y.; Kim, C. Anionic Ligand Effect on the Nature of Epoxidizing Intermediates in Iron Porphyrin Complex-Catalyzed Epoxidation Reactions. Inorg. Chem. 2002, 41, 3647−3652. (32) Reed, J. C. A.; Mashiko, T.; Bentley, S. P. W.; Kastner, M. E.; Scheidt, W. R.; Spartalian, K.; Lang, G. The missing heme spin state and a model for cytochrome c′. The mixed S = 3/2, 5/2 intermediate spin ferric porphyrin: perchlorate(meso-tetraphenylporphinato)iron(III). J. Am. Chem. Soc. 1979, 101, 2948−2958. (33) Honeychuck, R. V.; Hersh, W. H. Coordination of “Noncoordinating” Anions: Synthesis, Characterization, and X-ray Crystal Structures of Fluorine-Bridged [SbF6]−, [BF4]−, and [PF6]− Adducts of [R3P(CO)3(NO)W]+. An Unconventional Order of Anion Donor Strength. Inorg. Chem. 1989, 28, 2869−2886. (34) Lü, H. Y.; Deng, C. L.; Ren, W. Z.; Yang, X. Oxidative desulfurization of model diesel using [(C4H9)4N]6Mo7O24 as a catalyst in ionic liquids. Fuel Process. Technol. 2014, 119, 87−91. (35) Shiraishi, Y.; Tachibana, K.; Hirai, T.; Komasawa, I. Desulfurization and Denitrogenation Process for Light Oils Based on Chemical Oxidation followed by Liquid-Liquid Extraction. Ind. Eng. Chem. Res. 2002, 41, 4362−4375. (36) Zhang, X. W.; Shi, Y. W.; Liu, G. Z. Direct preparation of [(CH3)3NC16H33]4Mo8O26 and its catalytic performance in oxidative desulfurization. Catal. Sci. Technol. 2016, 6, 1016−1024. (37) Nagpal, P. K. R.; Chauhan, P.; Yatindranath, V.; Chauhan, S. M. S.; Kumari, P. Efficient iron(III) porphyrins-catalyzed oxidation of guanidoximes to cyanamides in ionic liquids. J. Chem. Sci. 2015, 127 (1), 13−18. (38) Meng, Z.; Dolle, A.; Carper, W. R. Gas phase model of an ionic liquid: semi-empirical and ab initio bonding and molecular structure. J. Mol. Struct.: THEOCHEM 2002, 585, 119−128. (39) Kumari, P.; Nagpal, R.; Chauhan, S. M. S. Efficient oxidation of polycyclic aromatic hydrocarbons with H2O2 catalyzed by 5,10,15triarylcorrolatoiron (IV) chloride in ionic liquids. Catal. Commun. 2012, 29, 15−20. (40) Volz, T. J.; Rock, D. A.; Jones, J. P. Evidence for Two Different Active Oxygen Species in Cytochrome P450 BM3Mediated Sulfoxidation and N-Dealkylation Reaction. J. Am. Chem. Soc. 2002, 124, 9724−9725. (41) Baciocchi, E.; Gerini, M. F.; Lapi, A. Synthesis of Sulfoxides by the Hydrogen Peroxide Induced Oxidation of Sulfides Catalyzed by Iron Tetrakis(pentafluorophenyl)porphyrin: Scope and Chemoselectivity. J. Org. Chem. 2004, 69 (10), 3586−3589. (42) Baciocchi, E.; Lanzalunga, O.; Pirozzi, B. Oxidations of Benzyl and Phenethyl Phenyl Sulfides. Implications for the Mechanism of the Microsomal and Biomimetic Oxidation of Sulfides. Tetrahedron 1997, 53 (36), 12287−12298. (43) Iamamoto, Y.; Assis, M. D. D.; Baffa, O.; Nakagaki, S.; Nascimento, O. R. Study by EPR and Electronic Spectroscopy of Intermediates in Iron Porphyrin and Iodosylbenzene Reaction. J. Inorg. Biochem. 1993, 52, 191−200. (44) Yin, J. M.; Wang, J. P.; Li, Z.; Li, D.; Yang, G.; Cui, Y. N.; Wang, A. L.; Li, C. P. Deep desulfurization of fuels based on an oxidation/ extraction process with acidic deep eutectic solvents. Green Chem. 2015, 17, 4552−4559. (45) Thornalley, P. J.; Trotta, R. J.; Stern, A. Free radical involvement in the oxidative phenomena induced by tert-butyl hydroperoxide in erythrocytes. Biochim. Biophys. Acta, Gen. Subj. 1983, 759, 16−22.

(46) Schulz, C. E.; Devaney, P. W.; Winkler, H.; Debrunner, P. G.; Doan, N.; Chiang, R.; Rutter, R.; Hager, L. P. Horseradish peroxidase compound I: evidence for spin coupling between the heme iron and a ‘free’ radical. FEBS Lett. 1979, 103, 102−105. (47) Rebelo, S. L. H.; Pereira, M. M.; Simoes, M. M. Q.; Neves, M. G. P. M. S.; Cavaleiro, J. A. S. Mechanistic studies on metalloporphyrin epoxidation reactions with hydrogen peroxide: evidence for two active oxidative species. J. Catal. 2005, 234, 76−87. (48) Nam, W. O.; Lim, M. H.; Lee, H. J.; Kim, C. Evidence for the Participation of Two Distinct Reactive Intermediates in Iron(III) Porphyrin Complex-Catalyzed Epoxidation Reactions. J. Am. Chem. Soc. 2000, 122, 6641−6647. (49) Adler, A. D.; Longo, F. R.; Finarelli, J. D.; Goldmacher, J.; Assour, J.; Korsakoff, L. A Simplified Synthesis for mesoTetraphenylporphin. J. Org. Chem. 1967, 32, 476. (50) Adler, A. D.; Longo, F. R.; Kampas, F.; Kim, J. On the preparation of metaloporphyrins. J. Inorg. Nucl. Chem. 1970, 32, 2443. (51) Li, H. M.; Zhu, W. S.; Wang, Y.; Zhang, J. T.; Lu, J. D.; Yan, Y. S. Deep oxidative desulfurization of fuels in redox ionic liquids based on iron chloride. Green Chem. 2009, 11, 810−815. (52) Xiong, J.; Zhu, W. S.; Li, H. M.; Xu, Y. H.; Jiang, W.; Xun, S. H.; Liu, H.; Zhao, Z. Immobilized Fenton-Like Ionic Liquid: Catalytic Performance for Oxidative Desulfurization. AIChE J. 2013, 59 (12), 4696−4704. (53) Zhu, W. S.; Wu, P. W.; Yang, L.; Chang, Y. H.; Chao, Y. H.; Li, H. M.; Jiang, Y. Q.; Jiang, W.; Xun, S. H. Pyridinium-based temperature-responsive magnetic ionic liquid for oxidative desulfurization of fuels. Chem. Eng. J. 2013, 229, 250−256. (54) Hu, Y. W.; He, Q. H.; Zhang, Z.; Ding, N. D.; Hu, B. X. Oxidative desulfurization of dibenzothiophene with hydrogen peroxide catalyzed by selenium(IV)-containing peroxotungstate. Chem. Commun. 2011, 47, 12194−12196. (55) Xu, J. H.; Zhao, S.; Chen, W.; Wang, M.; Song, Y. F. Highly Efficient Extraction and Oxidative Desulfurization System Using Na7H2LaW10O36·32H2O in [bmim]BF4 at Room Temperature. Chem. - Eur. J. 2012, 18, 4775−4781. (56) Zhu, W. S.; Dai, B. L.; Wu, P. W.; Chao, Y. H.; Xiong, J.; Xun, S. H.; Li, H. P.; Li, H. M. Graphene-Analogue Hexagonal BN Supported with Tungsten-based Ionic Liquid for Oxidative Desulfurization of Fuels. ACS Sustainable Chem. Eng. 2015, 3, 186−194. (57) Huang, L. C.; Wang, G. F.; Qin, Z. F.; Dong, M.; Du, M. X.; Ge, H.; Li, X. K.; Zhao, Y. D.; Zhang, J.; Hu, T. D.; Wang, J. G. In situ XAS study on the mechanism of reactive adsorption desulfurization of oil product over Ni/ZnO. Applied Catalysis B: Environmental 2011, 106, 26−38. (58) Meier, P. F.; Reed, L. E.; Greenwood, G. J. Removing gasoline sulfur. Hydrocarbon Eng. 2001, 26−32.

2055

DOI: 10.1021/acssuschemeng.6b02916 ACS Sustainable Chem. Eng. 2017, 5, 2050−2055