Study on the performance and mechanism of aerobic oxidative desulfurization based on a dual-functional material possessing catalytic and adsorptive properties

Article abstract of DOI:10.1039/c8nj05896b

Herein, three polyoxometalates, namely K₃PW₁₂O₄₀·10H₂O, K₆[α-P₂W₁₈O₆₂]·14H₂O, and K₈H[P₂W₁₅V₃O₆₂]·9H₂O, were successfully prepared and used in the air/n-octanaloxidative desulfurization (ODS) system. Among the compounds, the Dawson-type polyoxometalate K₆[α-P₂W₁₈O₆₂]·14H₂O exhibited the best performance, with a 99.63% desulfurization ratio. Then, K₆[α-P₂W₁₈O₆₂]·14H₂O was supported on graphene oxide (GO) to obtain K₆P₂W₁₈O₆₂/GO. The prepared catalysts were characterized by Fourier transform infrared spectroscopy (FTIR), ³¹P nuclear magnetic resonance (³¹P NMR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), and Boehm titration. Using K₆P₂W₁₈O₆₂/GO as a catalyst, a final sulfur removal ratio of 96.10% was achieved without extraction post-treatment due to the inherent adsorption capacity of the catalyst. In addition, the factors influencing the desulfurization process were investigated. The recovery experiment showed that the supported catalyst could be reused 5 times with slight catalyst deactivation. Finally, the reaction mechanism was proposed with the aid of gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and contrast tests.

Full text of DOI:10.1039/c8nj05896b

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Study on performance and mechanism for aerobic oxidative
desulfurization based on the dual-functional material possessing
catalytic and adsorptive properties
Received 00th January 20xx,
Accepted 00th January 20xx
a
a
DOI: 10.1039/x0xx00000x
Shuai-yong Dou, Rui Wang*
www.rsc.org/
Abstract:Three polyoxometalates including K
successfully prepared and used in the air/n-octanaloxidative desulfurization (ODS) system. In which, Dawson-type
polyoxometalateK [α-P 62]·14H O exhibited the best performance with 99.63% of desulfurization ratio. Then, K [α-
62]·14H O was supported on graphene oxide (GO) to obtain K 62/GO.The prepared catalysts were
characterized by Fourier transform infrared spectra(FT-IR), 31P Nuclear Magnetic Resonance ( PNMR), X-ray diffraction
3 2 6 2 18 2 8 2 15 3 2
PW12O40·10H O, K [α-P W O62]·14H O, and K H[P W V O62]·9H O were
6
2 18
W O
2
6
P
2 18
W O
2
6 2 18
P W O
31
(
XRD), scanning electron microscopy (SEM), Energy dispersive X-ray spectra (EDX), transmission electron microscopy
TEM), and Boehm titration. Using K 62/GO as catalyst, the final sulfur removal ratio could achieve 96.10% without
(
6 2 18
P W O
extraction post-treatment due to its inherent adsorption capacity. In addition, the influencing factors on the
desulfurization were investigated. The recovery experiment showed that the supported catalyst could be reused for 5
times with little catalysis deactivation. Finally, the reaction mechanism was proposed with the aid of the gas
chromatography
(GC),
gas
chromatography-mass
spectrometry
(GC-MS)
and
contrast
test.
hydrocarbonsand hydrogen sulfide gas, and then the
desulfurization was achieved throughthe removal of the
1
. Introduction
Facing the increasingly serious global environmental problems,
governments have promulgated a series of regulations to
9
hydrogen sulfide by adsorption or other methods. Through
years of study, HDS has already become a mature technology
10-12
and widely used in industry.
However, the HDS was always
1
,
2
prevent and control pollution in city.
More recently,
carried out under high temperature and high
hydrogenpressure, as well as its low efficiency in the
heteroaromaticsulfurcompounds removal, making it large
capital investment and energy consumption in need to meet
the new sulfur emission regulations. Concerning this
undeniable problem, the researchers have been trying to
explore more effective desulfurization methods over the last
decades, and the oxidative desulfurization (ODS) and
adsorptiondesulfurization (ADS) are widely sought after with
their mild reaction conditions and high efficiency for
sulfuremission of vehicle has been limited to 10 ppmw in many
countries.3 For one thing, the combustion of sulfur
compounds in fuel oil will bring various health and
environmental hazards to human such as the formation of acid
rain, promotion of hazardous particulates, and inducement of
respiratory disease. For another, the residualsulfur compounds
in fuel oil will poison the diesel oxidation catalyst, thus
reducing the removal efficiency of other harmful emissions
,
4
X
including unburned hydrocarbon (HC), nitrogen oxides (NO ),
and other odour gases to take multiple harmful
consequences.5 6In short, the sulfuremission is
pressing environmental problem of this moment, especially in
the developing counties.
deep desulfurization of fuel oil is becoming an important
subject in both academia and industry, and deeply studied by
the relevant scholars. In earlier research, the sulfur
compounds in fuel oil were mainly removed by
hydrodesulfurization (HDS) method. In the process, the sulfur
compounds reacted with hydrogen to obtain the
heteroaromaticsulfurcompounds
benzothiophene(BT), dibenzothiophene(DBT), and 4,6-
dimethyldibenzothiophene(4,6-DMDBT).
removal,
such
as
,
a
13-15
7
, 8
Underthis background, the ultra-
In the ODS process, stubbornorganosulfur compounds in non-
polar fuel oil were oxidized to their strong polar products such
as sulfonesorsulfoxides, and the oxidation products were
removed through polar solvent extraction or adsorption. The
16
frequently-used oxidants for ODS include H
2
2
O ,
organic
17
18
19
peroxide,
molecular oxygen,
and solid peroxide. As a
great potential one, the molecular oxygen (or air) exhibited
incomparable advantages with its inexpensiveness, wide
resource, environmental friendliness and safety for storage.
Therefore, many researchers have begun to explore the ODS
School of Environmental Science and Engineering, Shandong University, No. 27
Shanda South Road, Jinan 250199, P. R. China.E-Mail: wangrui@sdu.edu.cnTel:
86-531-88366367
Electronic Supplementary
DOI: 10.1039/x0xx00000x
+
20, 21
Information
(ESI)
available.
See system using molecular oxygen or air as oxidant.
This journal is © The Royal Society of Chemistry 20xx
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However, due to its low reactivity, some extra conditions must used for ADS process. However, some recenVtiewreAsrteicalerOcnhlienes
be provided to activate the molecular oxygen when used for showed that a few carbon materials cDoOulI:d10a.1d0s3o9r/Cb8NthJe058O9D6BS
ODS. The common methods to activate the molecular oxygen products sulfonesorsulfoxides more easily than the untreated
2
2,
in ODS include high temperature treatment,
sulfur compounds in fuel oil. For instance, chenet al. used
and so on. As early as 2004, Murataet al. activated clay as the adsorbent for the sulfone compounds
2
3
24, 25
photocatalysis,
have proposed an interestingstrategy to reach the ultra-deep produced in the ODS process catalyzed by phosphotungstic
desulfurization under mild conditions with the aid of aldehyde acid, and the sulfur content in the treated fuel oil was below
co-assistant. 26 However, the studies in this field have been 10 ppm. 43 Yang et al. used modified activated carbon to
relatively few since then, and one of the important reasons to adsorb the sulfones obtained through the pre-oxidation of
limit the application of this technology is the carboxylic acid sulfur compounds in fuel oil, and impressivesulfur removal
produced through the oxidation of aldehyde will be residual, efficiency had been achieved in both of model oil and real oil.
thus affecting the quality of the fuel oil.
The polyoxometalates have been widely used for ODS process produced in the octanal-airODS system, and a notable
due to its remarkable catalytic performance, and the most desulfurization result was achieved in model oil.
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Zhang et al. used GO as the adsorbent for the sulfones
4
5
2
7-
frequently usedpolyoxometalates are the Keggin-type ones.
Due to the high desulfurization efficiency of ODS and ADS, this
Auniversally accepted mechanism for these researches is as work aimed at designing a dual-functional material possessing
follows: the polyoxometalates reacted with the oxidant H catalytic and adsorptive properties to realize the in-situ
to obtain peroxo-polyoxometalates which possessed high removal of sulfur compounds in oil. Inspired by previous work,
2
9
2 2
O
4
5
catalytic activity. Then, DBT would be oxidized to DBTO
peroxo-polyoxometalates and removed through polar solvent forsulfonesproduced in the octanal-air ODS system,
extraction. Therefore, the polyoxometalates (catalyst)/H corresponding to 45.1 mg-S/g-sorb. However, 89.21% of the
oxiatant)/polar solvent (extractant) system is the most mature final desulfurization ratio still could not meet the current ultra-
2
by the
we found that GO had a high adsorption capacity
2 2
O
(
ODS technology in this respect, and widely studied by the deep desulfurization requirement. Also, a large number of n-
relevant scholars. More recently, some researchers began to octanal must be provided (molar ratio of octanal/S was 24) to
explore the catalytic performance of Dawson-type oxidize the sulfur compounds. Hence, we designed the
polyoxometalates for ODS, which are another common composite catalyst K
6
P
2
W
18
O
62/GO through hydrothermal
For instance, method. Due to the excellent catalytic performance of K [α-
62 as the 62]·14H O in the octanal-air ODS system and the high
catalyst for ODS, and they proposed that the prepared adsorption capacity of GO forsulfones, 96.10% of the final
polyoxometalates could also react with H to obtain peroxo- desulfurization ratio could be achieved through the in-situ
3
0-32
polyoxometalates widely used in many fields.
Banisharifet al. used [cetrimonium]11
6
P
2
W
13
V
5
O
P
2
18
W O
2
2 2
O
polyoxometalates to oxidize the thiophene derivatives to their adsorption of the catalyst, and less n-octanal was needed
correspondingsulfones in the fuel oil/extractantbiphase (molar ration of octanal/S was 4) to oxidize the sulfur
systems, thus achieving the ultra-deep desulfurization by the compounds.To remove the produced carboxylic acid, the
3
3-35
extraction for the high-polar sulfones.
62 on carbon nanotubes to prepare a composite showedthat no carboxylic acid was residual in the fuel oil
catalyst for ODS using molecular oxygen as oxidant, and 99.4% through the multi-function of adsorption and extraction, and
Gaoet al. supported extraction treatment was added into the process.The result
8 2 2
H P Mo16V O
3
6
of DBT removal efficiency could be achieved.
the sulfur compounds in fuel oil could be completely removed
The sulfur compounds in fuel oil were removed by the in a very short time. An efficient and noveldesulfurization was
adsorption function in the ADS process. Therefore, to prepare proposed based on the prepared dual-functional material.
the adsorbents with excellent adsorptivity and high selectivity
for the target pollutants is the most critical step in the process.
After many scholars research in this field, varieties of superior
2
. Experimental
3
7-39
adsorbents were designed and used.
As a new kind of
2.1. Materials.
cheap adsorption materials, the carbon-based materials are
widely used for ADS recently. For instance, Danmalikiet al.used
the nickel/activated carbon (AC) as the adsorbent for DBT, and
All the chemicals were directly purchased from the suppliers
and used as received without furtherpurification. Detailedly,
dibenzothiophene(99%) and benzothiophene(99%) were
9
6% of sulfur removal ratio could be achieved in the model oil
obtained
from
Acros
Organics
(USA);
4,6-
4
0
with an initial sulfur content of 59 ppm. Saleh explored the
ADS performance of AC loaded withcobalt and copper, the
result showed that the adsorbent was not only applicable for
the DBT removal, but also for other kinds of
thiophenederivatives. Menzel et al. supportedlayered double
hydroxides onto exfoliatedGO, and the composite exhibited
excellent adsorption capacity, pronounced selectivity and fine
recycling property in the ADS process.
The carbon-based materials exhibited excellent adsorption
performance for the sulfur compounds in fuel oil, and directly
dimethyldibenzothiophene(97%) were obtained from J&K
Chemicals (China); acetonitrile (99%), n-octane (95%),
potassium chloride (99.5%), sodium perchloratemonohydrate
99%), xylene (98%) and sodium nitrate (99%) were obtained
from Tianjin Kermel Chemicals (China); sodium tungstate
97%), ethanol absolute (99.9%) and sodium metavanadate
98%) were purchased from Tianjin Fuchen Chemicals (China);
phosphoric acid (85wt%) and hydrogen peroxide (30wt%) were
purchased from Laiyang Kant Chemicals (China); n-octanal
(
4
1
(
(
4
2
2
| J. Name., 2012, 00, 1-3
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(97%),octanoic acid (97%) and n-octylene (97%) were available mixtures were treated by 400 ml deionized wateVirewaAnrdticle3O0nlminel
from Aladdin Chemicals (China); potassium carbonate(99%) hydrogen peroxide, and theobtained suDsOpeI:n10si.1o0n39w/Ca8sNJfi0lt5e8r9e6dB
was available from Tianjin Dengke Chemicals (China); sodium and washed with 10% hydrochloric acid solution. The solid was
chloride (99%) was obtained from Tianjin Guangcheng collected and washed with deionized water and absolute
Chemicals (China); sodium carbonate anhydrous(99%) and ethanoluntil the filtrate was neutral. Finally, GO product was
Phosphotungstic acid (97%) were purchased from Sinopharm obtained through vacuum freeze-drying.
(
China); natural graphite(99.9%) was purchased from Qingdao The supported catalyst was prepared by the following method:
HuataitechCompany (China); and potassium The given amount of GO was dispersed in 80 ml deionized
permanganate(99.5%) was available from Guangzhou Liqiang water under ultrasonic treatment for 3 h to obtain suspension
Chemicals (China). All the used regents were analytically pure. A, and corresponding amount of K O was
.2. Characterization
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6 2 18 2
P W O62·14H
2
dissolved in 15 ml deionized water to obtain solution B. Then,
solution B was drop by drop added in suspension A and stirred
for 2 h at room temperature to obtain mixture C. Mixture C
was treated by hydrothermal method at 100 C for 24 h, and
washed with deionized water and absolute ethanol. Finally,
FT-IR spectra of the samples were collected using ALPHA-T
Fourier Transform Infrared Spectrometer (BRUKER Corp.,
Germany), with a range of 400-4000 cm .KBr pellet was used
o
−1
31
in the measurement.
PNMRspectra were recorded
the supported catalyst K
vacuum freeze-drying.
6 2 18
P W O62/GO was obtained through
onADVANVE 400 MHZ NMR spectrometer (BRUKER Corp.,
Germany). XRD patterns were recorded by D8 ADVANCE
instrument (BRUKER Corp., Germany) using Cu-Kα radiation (λ
2
.4 Oxidative Desulfurization Experiment.
=
0.15405 nm, 40 KV × 60 mA). SEM micrographs were The experiment was carried out in a three-necked
obtained by JSM-6700F field emission scanning electron flaskimmersed in constant temperature bath. When the
microscopy (JEOL Corp., Japan), equipped with an Oxford INCA setting temperature was reached, 60 ml model oil was added
X sight energy spectrum analyzer using the acceleration in the flask, and the model oil was prepared by fully
voltage of 2 kV. TEM micrographs were taken by JEM-1011 dissolvingDBT in n-octane (corresponding S concentration was
transmission electron microscope (JEOL Corp., Japan).
.3. Preparation of the Catalysts.
[α-P 62]·14H and
prepared according to the literature methods.
type polyoxometalatesK was prepared
according to the literature method with some modifications.
In a typical synthesis, 9.792 g (0.0034 mol) H
calculated as 250 ppmw). Then, the catalyst (0.5 wt%) and n-
octanal (molar ration of octanal/S was 4) were successively
added into the model oil. The air with the flow rate of 200
ml/min was bubbled into the reaction mixture, and the stirring
was started. At set intervals, the model oil (1 μl) was sampled
and extracted by MeCN, if necessary.Thesulfur content in the
samples was determined by a micro-coulomb comprehensive
analysis meter (WK-2E). The desulfurization ratio was
calculated by the following equation:
Desulfurization ratio (%) = (C
Where, C represented the initial sulfur content in the model
oil, C represented the sulfur content after treated for t time.
.5. Recovery Experiment.
2
K
6
2 18
W O
2
O
K
8
2
H[P W
15
V
3
4
O
62]·9H
TheKeggin-
2
Owere
6, 47
3
2
PW12O40·10H O
4
8
3 2
PW12O40·xH O
was fully dissolved in 100 ml deionized water to obtain a clear
solution A, and 0.7823 g (0.011 mol) KCl was dissolved in 50 ml
deionized water to obtain solution B. The solution B was slowly
added into solution A over 30 min under vigorous stirring, and
the white precipitant was gradually formed. After stirred for
another 8 h, the white precipitant was collected by
centrifugation, and washed with deionized water for several When the oxidative desulfurization experiment was
times to remove chloride ion. The wet precipitation was completed, the reaction mixture was filtered to remove the
treated by vacuum freeze-drying to obtain K
0 t 0
-C )/C *100
0
t
2
3
PW12
O40·10H
2
O. liquid phase. The obtained solid was washed with MeCN for 3
o
The element compositions of the prepared polyoxometalates times, and dried at 60 C overnight. After these treatments,
were analyzed by inductively Coupled Plasma-atomic Emission the recovered catalyst was obtained and used in the
Spectrometry (ICP-AES) as follows: Anal. Calcd for desulfurization experiment again.
K
3
PW12O40·10H
2
O:K, 3.70; W, 69.49.Found: K, 3.75; W, 69.52.
[α-P 62]·14H O:K, 4.84; W, 68.23. Found:
K, 4.87; W, 68.29. Anal.Calcdfor K H[P O:K, 7.05;
W, 62.10; V, 3.44. Found: K, 7.11; W, 62.14; V, 3.42.
GO was prepared through the modified Hummer’s method.
Anal.Calcdfor K
6
2
W
18
O
2
3
. Results and discussion
8
2 15 3 2
W V O62]·9H
3
.1. Characterization of the Polyoxometalates.
4
5,
As shown in Figure. 1, the IR peaks of K PW12
3
O
40·10H
2
Oappear
4
9
Briefly, 3 g natural graphite powder, 1.5 g sodium nitrate
-1
-1
-1
-
at 1080 cm (P-O
a
), 983 cm (W=O
d
), 891 cm (W-O
b
), 800 cm
and 70ml concentrated sulfuric acid were added in the flask,
and cooled down in the ice bath. Then, 9 g potassium
permanganate was slowly added into the mixtures over 1 h.
After the addition, the resultant mixtures were stirred for 2 h
and the temperature was kept below 20 C. After that, the
mixtures were stirred for 30 min at 35 C.When the mixtures
1
(W-O
c
-W) and 526 cm-1 (W-P-W), which are the typical
5
0
Characteristic peaks of Keggin-type polyoxometalates. The IR
-1
peaks ofK
cm (W=O), 911 cm (W-O
6
[α-P
2
W
18
O
62]·14H
2
Oappear at 1089 cm (P-O), 961
-1
-1
-1
o
b
-W) and 780 cm (W-O
c
-W), which
are the typical Characteristic peaks of Dawson-type
o
4
6
polyoxometalates.
H[P
The
IR
peak
positions
of
were cooled to room temperature, 150 ml deionized water
was added and stirred for 3 h at 98 C. 15 minutes later, the
-1
K
8
2
W
15
V
3
O
62]·9H
2
-1
O mainly located at 1077 cm (P-O), 935
o
-1
-1
cm (V=O), 875 cm (W-O
b
-W), and 765 cm (W-O
c
-W), which
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are the Characteristic peaks of Vanadium-substituted Dawson-
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DOI: 10.1039/C8NJ05896B
4
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type polyoxometalates.
The IR results prove the
successfulpreparation of three polyoxometalates.
K PW O 10H O
3
12 40
2
Furthermore, the 31PNMR spectraof the prepared polyoxometalates
are given in Figure. 2. As shown in the figure, a major peak appears
at around -15.07 ppm in the spectrumof K
3
PW12
O
40·10H
2
O, as
reported in the reference. A major peak appears at around -12.7
ppm in the spectrumof [α-P 62]·14H O, which was
determined as α-isomer peak in reference. Two obvious peaks
appear at around -6.7 and -14.3 in the
spectrumofK H[P O, which is in agreement with that
K [-P W O ]14H O
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18 62
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2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
K
2
W
18
O
6
2
4
6
8
2 15 3 2
W V O62]·9H
47
K H[P W V O ]9H O
8 2 15 3 62 2
reported in the reference. The NMR results further indicate the
successful synthesis.
-20
-10
0
10
20
3
. 2.ODS Experiment Catalyzed by Polyoxometalates.
ppm
3
1
The ODS experiment was carried out as described in section 2.4. Fig. 2. PNMR spectraof the prepared polyoxometalates
Furthermore, then-octane solution containing 500 ppmwsulfur
content of DBT was used as model oil, and MeCN was used as
extractant to remove the oxidation products. As shown in Figure. 3,
100
the final desulfurization ratios in model oil catalyzed by K
6
[α-
O were 99.63% and 69.10% in
h, respectively. Obviously, the Dawson-type polyoxometalates
2 18 2 3 2
P W O62]·14H O and K PW12O40·10H
2
exhibited much higher catalytic activity than Keggin-type ones in
the aldehyde/O ODS system. The Vanadium-substituted Dawson-
type polyoxometalatesK H[P O was also synthesized
2
8
2 15 3 2
W V O62]·9H
and its catalytic performance was investigated in the ODS process.
As shown in Figure. 3, the final desulfurization ratio in model oil
catalyzed byK
in 4h, respectively. Both of the desulfurization ratio and reaction
rate were inferior toK [α-P 62]·14H O. Overall, [α-
62]·14H O with the highest activity was chosen as the
optimum catalyst to be further studied in the follow-up experiment.
8 2 15 3 2
H[P W V O62]·9H O were 92.99% in 2 h and 98.49%
K PW O 10H O
3
12 40
2
K HP W V O 9H O
6
2
W
18
O
2
K
6
50
8
2
15
3
62
2
K [-P W O ]14H O
2
P W
18
O
2
6
2
18 62
2
0
30
60
90
120
150
180
210
240
time/min
Fig. 3. The ODS curves over reaction time catalyzed by different polyoxometalates.
1089
o
(Condition: T=60 C;wcat.=0.5%;m
S
=500 ppmw; molar ratio of octanal/S is 4).
9
11
961
Note: T: reaction temperature; wcat.: catalyst dosage,m
S
: initial sulfur content.
1
010 780
1077
1045
3
.3. Characterization of K
GO and K 62/GO were prepared as described in section
.3 and characterized by FT-IR, XRD, SEM, EDX and TEM. As
shown in Figure. 4, IR peak positions of GO are mainly located
6 2 18
P W O62/GO.
765
875
935
6 2 18
P W O
2
K PW O 10H O
at 3427 cm-1, 1728 cm-1, 1628 cm-1, 1230 cm-1 and 1067 cm-1
,
3
12 40
2
526
K [-P W O ]14H O
6
2
18 62
2
corresponding to the characteristic peaks of oxygen-containing
functional groups as -OH, C=O, COOH, C-O-C and C-O,
respectively. The introduction of these functional groups prove
the successful preparation of GO. Furthermore, these peaks
K HP W V O 9H O
8
2
15
3
62
2
1080
891
800
983
3000
2500
2000
1500
1000
500
-1
wavenumber/(cm )
can be also observed in the spectrum of K
the Dawson-type characteristic peaks are also maintained,
indicating that [α-P 62]·14H was
successfullysupported on GO, and both of them kept their
originalstructures. Besides, it could be deduced that K [α-
62]·14H O was supported on GO only by physical
6 2 18
P W O62/GO and
Fig. 1. FT-IR spectraof the prepared polyoxometalates
K
6
2
W
18
O
2
O
6
2
P W
18
O
2
adsorption and no chemical reactions between them occurred,
since no new peaks were observed.
The successful preparation of thematerials is also confirmed by
XRD method. As shown in Figure. 5, the crystal surface
4
| J. Name., 2012, 00, 1-3
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6
o
characteristic diffraction peak of GO (002) at around 11 is
clearly observed in the XRD patternof GO, proving its
View Article Online
GO
DOI: 10.1039/C8NJ05896B
4
5
successful preparation. For K
6
P
2
W
18
O
62/GO, the sharp peak at
o
o
around 11 disappears, and a board peak at 20~30 is
5
2
observed. This is in agreement with the literature work.
Besides, no diffraction peaks which appear in the XRD pattern
of K [α-P 62]·14H O can be observed in the pattern of
K [-P W O ]14H O
6
2
18 62
2
6
2 18
W O
2
supported catalyst, which may be caused by the well
dispersion of the polyoxometalate on GO.
As shown in Figure. 6, the layered structure as well as bending
in the edge is observed in the SEM image of GO, which is
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
K P W O /GO
6
2
18 62
4
5, 49
similar with the traditional GO structure.
structure is maintained in the SEM image of K
indicating the structure of GO was not destroyed in the
preparation process. Besides, K [α-P 62]·14H O was not
observed on the supported catalyst, confirming the well
dispersion of polyoxometalate on GO. As shown in the EDX
spectra, the element carbon, oxygen, potassium,phosphorus,
and tungsten can be observed in the spectra of supported
catalyst, indicating the successful preparation of the supported
catalyst. The similar result is also observed in Figure. 7. For one
thing, clear wrinkle could be observed in the TEM image of GO,
which was consistent with previous report. For another, the
TEM image of K 62/GO also illustrated the wrinkle
structure, and the uniform dispersion of polyoxometalate on
GO makes the supported catalyst darker than pure GO.
According to the analysis, it could be concluded
The same
P W O62/GO,
6 2 18
1
0
20
30
40
50
60
70
80
6
2
W
18
O
2
2
-Theta (degree)
Fig. 5.XRD patternsof GO andK P W O62/GO.
6 2 18
4
5
6 2 18
P W O
a
c
b
6 2 18
thatK P W O62 was successfully supported on GO, and the
supported catalyst still maintained the original morphology of
GO.
d
6 2 18
Fig. 6.SEM and EDX images of GO (a) (c) andK P W O62/GO (b) (d).
1089
1
728
911
961
1
230
067
1
1628
7
80
GO
K P W O /GO
a
b
6
2
18 62
3
427
6 2 18
Fig. 7.TEM images of GO (a) andK P W O62/GO (b).
3500
3000
2500
2000
1500
1000
500
-1
wave number/cm
3
.4. Effects of Different Parameters on ODSCatalyzed
byK
As was stated above, K
catalytic performance in aldehyde/O
6 2 18
Fig. 4.FT-IR spectraof GO and K P W O62/GO.
6 2 18
P W O62/GO.
6
[α-P
2
W
18
O
62]·14H
2
O exhibited the best
ODS system,
corresponding to 99.63% of final desulfurization ratio. Also, it
was successfullysupported on GO, and both of them kept their
originalstructures. Therefore, we supposed that the prepared
2
K
6
P
2
W
18
O
62/GO could act as a bi-functional material possessing
the catalytic activity and adsorption ability, thus making up
some deficiencies existing in the previous aldehyde/O ODS
2
system using pure GO as adsorbent, such as the large
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aldehydeneed (molar ration of octanal/S was 24) and the different parameters on ODS including temperature, initial
unsatisfactory desulfurization ratio (89.21%). To prove our sulfur content, different sulfur compounds and selectivity.
hypothesis, we carried out aldehyde/O ODS experiment In ODS process, temperature is an important factor to be
catalyzed by K
was chosen as 4.
the supported catalysts with different K
loading amounts including 10%, 15%, 17.5%, 20% and 30% in previous work,
were synthesized and evaluated in ODS process. The element process. Therefore, it is necessary to determine a suitable
compositions of the prepared catalysts were analyzed by reaction temperature to provide the high desulfurization ratio
inductively Coupled Plasma-atomic Emission Spectrometry in mild conditions. As shown in Figure. 9, the final
View Article Online
DOI: 10.1039/C8NJ05896B
4
5
2
6 2
P
W
18
O
62/GO, and the molar ratio of octanal/S investigated. In practical industry, large energy consumption
must be provided to reach high temperature, thus causing
huge capital investment and inevitable pollution. As reported
6
[α-P
2
W
18
O
62]·14H
2
O
1
4, 28
high temperature is favor for the ODS
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
o
o
o
(ICP-AES) as follows: Anal. Calcdfor 10%-K
6
[α-P
2 18
W O62]/GO:K, desulfurization ratios at 40 C, 60 C and 80 C were 36.84%,
0
P
1
1
P
.48; W, 6.82. Found: K, 0.43; W, 6.64. Anal.Calcdfor 15%-K
6
[α- 96.10% and 96.77% respectively. In both regards of
o
2 18
W O62]/GO:K, 0.73; W, 10.23. Found: K, 0.70; W, desulfurization efficiency and energy consumption, 60 C was
0.01.Anal.Calcdfor 17.5%-K
1.94. Found: K, 0.83; W, 11.91.Anal.Calcdfor 20%-K
6
[α-P
2
W
18
O
62]/GO:K, 0.85; W, chosen as the most suitable temperature. Besides, the final
o
6
[α- desulfurization ratio treated by GO adsorption at 60 C was
4
5
2 18
W O62]/GO:K, 0.97; W, 13.65. Found: K, 0.91; W, 13.31. 89.21% ( the molar ratio of octanal/S is 24), which was lower
Anal.Calcdfor 30%-K
6
[α-P 62]/GO:K, 1.45; W, 20.47. than 96.10% catalyzed by K 62/GO, proving the
2
W
18
O
6 2 18
P W O
Found: K, 1.37; W, 20.11. As shown in Figure. 8, the optimum supported polyoxometalates still exhibited catalytic activity for
loading amount could be determined as 17.5%, corresponding ODS.Furthermore, the reaction rate catalyzed by
to 92.46% of final desulfurization ratio, without extraction.
This could be explained in two aspects: On one hand, the the catalytic effect of K
active component (K [α-P 62]) was insufficient for the slowed down as reaction went on. This might be caused by the
oxidation reaction when the loading amount was low, leading covering effect of adsorbed oxidation products for the active
to the lower sulfur removal ratio. This can explain the increase sites.
of the desulfurization ratio when the loading amount raised
K
6
P
2
W
18
O
62/GO was much faster at initial stage, also proving
6 2 18
P W O
62. However, the reaction rate
6
2 18
W O
1
00
form 10% to 17.5%.To confirm the assumption, the effect of
[α-P 62] dosage on the desulfurization ratio was given
(
17.5, 92.46)
K
6
2 18
W O
(
15, 86.78)
in Figure S1 (ESI), it could be seen that the desulfurization ratio
raised from 89.21% to 98.73%, when the catalyst dosage
raised from 0.05% to 0.1%, and almost kept constant
subsequently, indicating the oxidation reaction would be
(20, 85.92)
80
(
30, 72.35)
(10, 71)
6 2 18
incomplete with too low K [α-P W O62] dosage. On the other
hand, the excessive loading might cause the change of the
specific surface area and functional group contents of the GO
support, both of which were important for its adsorption
capacity for the oxidation products. To analyze the influence of
the surface area, the catalysts with different loading amounts
were analyzed using the Brunauer-Emmett-Teller (BET) model,
60
2
2
2
2
40
and the SBET were 52.4 m /g, 54.5 m /g, 51.2 m /g, 50.7 m /g,
1
0
15
20
25
30
2
2
4
7.4 m /g, and 45.2 m /g,corresponding to the different
loading amounts of 0% (pure GO), 10%, 15%, 17.5%, 20% and
0%. Due to the well dispersion of the polyoxometalate on
loading amount/%
Fig. 8. The desulfurization ratio curves over loading amount of polyoxometalates in
3
o
K
6
P
2
W
18
O
62/GO. (Condition: T=60 C;wcat.=0.5%;m
S
=500 ppmw; molar ratio of octanal/S
GO,no obvious change of the surface area had been observed is 4; the reaction time was 4 h).
after the supporting process, indicating that the surface area
was not an important influence factor for the adsorption Table 1.Boehm titration results of the catalysts with different loading amount of K
capacity. Besides, the functional group contents of the
catalysts were determined through Boehm titration, and the
results were shown in Table 1. It could be seen that the
functional group contents decreased with the increase of
loading amount. Therefore, we deduced that the decrease of
the desulfurization ratio when the loading amount raised form
6
[α-
2 18 2
P W O62]·14H O
Contents (mmol/g)
Lactonic
6.249
5
3
Samples
GO
Carboxylic
4.976
4.212
4.014
3.967
Phenolic
0.677
0.631
0.609
0.589
0.532
0.499
10%-K
6
[α-P
2
W
18
O
62]/GO
15%-K [α-P W O ]/GO
5.417
5.188
5.099
4.711
6
2
18 62
1
7.5% to 30% might be caused by the reduction of the 17.5%-K [α-P W O ]/GO
6
2
18 62
adsorption capacity for the oxidation products, due to the
decrease of the functional group contents in the catalysts.
According the above analysis, K P W O62/GO with 17.5%
6 2 18
loading amount was chosen as the optimum catalyst and
further used in the follow-up work to investigate the effects of
20%-K
3
6
[α-P
[α-P
2
W
18
O
62]/GO
62]/GO
3.544
3.119
0%-K
6
2
W
18
O
4.151
6
| J. Name., 2012, 00, 1-3
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100
When ODS process was completed, the supported catalyst was
View Article Online
90
DOI: 10.1039/C8NJ05896B
recovered according to the method described in section 2.5,
80
and the recovered catalyst was used in the next ODS
experiment. As shown in Figure. 13, the final desulfurization
ratios in the first recycle, second recycle , third recycle, forth
recycle, and fifth recyle were 95.60%, 95.25%, 94.07%, 92.16%
and 90.05%, respectively, indicating that the supported
catalyst could be reused at least for 5 times with little catalysis
deactivation.
70
60
50
o
45
6
0 C by GO
o
4
0 C by supported catalyst
o
60 C by supported catalyst
o
80 C by supported catalyst
0
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1
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9
0
1
2
3
4
5
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8
9
0
40
30
20
10
0
100
80
0
30
60
90
120
150
180
210
240
270
300
time/min
Fig. 9. The ODS curves over reaction time at different
temperature.(Condition:wcat.=0.5%;m =250ppmw; vair = 200 ml/min; molar ratio
of octanal/S is 4. The condition for the reaction by pure GO was as the same as
60
S
4
5
S
reference : wcat.=0.5%;m =250ppmw; molar ratio of octanal/S is 24.).
4
0
0
0
In practical industry, the sulfur content in different liquid oil
products vary greatly. Therefore, to investigate the catalytic
performance in the oil with different initial sulfur content is of
significance for practical application. As shown in Figure. 10,
the final desulfurizationratios were 96.10%, 93.44% and
250 ppm
50 ppm
00 ppm
2
3
5
9
2.46%, corresponding to the initial sulfur content of 250
0
30
60
90
120
150
180
210
240
270
300
ppmw, 350 ppmw and 500 ppmw, respectively. It could be
seen that the supported catalyst exhibited excellent
performance in a broad range of initial sulfur contents.
The real oil contains variousheteroaromaticsulfur compounds
which are difficult to remove. Therefore, it is imperative to
time/min
Fig. 10. The ODS curves over reaction time for different initial sulfur content.
o
(Condition: T=60 C; wcat.=0.5%;molar ratio of octanal/S is 4).
100
6 2 18
explore the catalytic activity of K P W O62/GO for different
sulfur compounds besides DBT. As shown in Figure. 11, the
final desulfurizationratios were 96.10%, 92.03% and 31.26%,
corresponding to DBT, 4,6-DMDBT and BT. The reactivity were
in the order of DBT>4.6-DMDBT>BT. This result could be
explained in previous work:
density was more favor of the oxidation of sulfur compounds.
For another, space steric hindrance on S atom was an obstacle
to the reaction.
The real liquid oil is a complexmixture consisting of various
liken-alkane, aromatics and unsaturated hydrocarbons.
Therefore, it is instructive to evaluate the selectivity of catalyst
for ODS. As shown in Figure. 12, n-octylene and xylene were
used as the representative components to evaluate the
80
60
40
14, 28
For one thing, higher electron
20
BT
DBT
4
,6-DMDBT
0
0
30
60
90
120
150
180
210
240
270
300
time/min
selectivity of
desulfurizationratios decreased from 96.10% to 43.25% and
4.10%, when 10% n-octylene and 10% xylene were added
6 2 18
K P W O62/GO for ODS. The final
Fig. 11. The ODS curves over reaction time for different sulfur compounds. (Condition:
o
T=60 C; wcat.=0.5%; m
S
=250ppmw;molar ratio of octanal/S is 4).
2
into the model oil, respectively. Obviously, the supported
catalyst exhibited poor selectivity in the process, and this
could be attributed to the competitive oxidation between DBT
and the added organics. To improve the desulfurization ratios,
the extraction of MeCNwas carried out as an after-treatment
process. As shown in Table S1 (ESI), 94.31% and 84.45% of
desulfurization ratios could be achieved in sample 2 and
sample 3, respectively, when they were treated by ODS
process as well as extraction of MeCN.
3
.5. Recovery ofthe Supported Catalyst for ODS.
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only DBT
containing10% n-octylene
containing 10% xylene
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94
92
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0
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10
15
20
25
30
62/GO
0
30
60
90
120
150
180
210
240
270
300
time/min
time/min
6 2 18
Fig. 14. The ODS curves over reaction time catalyzed by K P W O
o
combined with after-treatment of extraction by MeCN. (Condition: T=60 C;
cat.=0.5%; m =250ppmw;molar ratio of octanal/S is 4).
Fig. 12. The ODS curves over reaction time in model oil with different components.
(Condition: T=60 C; wcat.=0.5%; m
w
S
o
S
=250ppmw; molar ratio of octanal/S is 4).
As shown in the figure, a fast ODS reaction occurred, and the
sulfur compounds could be completely removed in 20 min.
100
Compared with that catalyzed by K
shown in Figure. 3), both of the reaction rate and
desulfurization ratio have been improved greatly. As shown in
figure. S2 (d), no DBTO and octanoic acid had been observed
in the model oil, and a clean model oil was obtained. Since
DBTO could be dissolved into the hydrophilicMeCN phase, its
6 2 18 2
[α-P W O62]·14H O
(
80
60
40
20
0
2
2
covering effect for the active sites was effectively avoided, and
a faster reaction occurred compared with that treated without
extraction process (shown in Figure. 9).
The comparison of the studied system with reported work was
given in Table S2 (ESI). As shown in the table, the studied
system exhibited obvious advantageswith the mild reaction
conditions, high desulfurization ratio and excellent
recoverability.
1
2
3
4
5
reused times
Fig. 13.The final desulfurization ratios in different recycle process.(Condition:
o
T=60 C; wcat.=0.5%; m
S
=250ppmw; reaction time is 5 h; molar ratio of octanal/S 3.7. The contrast experiment and proposed mechanism.
is 4).
polyoxometalatesand n-octanal were involved in the studied
ODS system. Therefore, two mechanisms for ODS reported in
3
.6 The determination for ODS products.
2
6, 28
the literatures might be referenced.
previous work, 28polyoxometalates could react with H
Asreported in
to
The GC-MS was used to determine the products in the studied
system. As shown in Figure. S2, DBT in model oil was oxidized
to its correspondingsulfones DBTO , and n-octane was oxidized
2
to octanoic acid. It could be seen from Figure. S2 (b) that some
octanoic acid was residual in the model oil after reaction, and
2
the residualsulfurcompound was determined as DBTO ,
indicating DBT was completely oxidized, and the limitation to
the desulfurization ratio was the incomplete adsorption
removal for DBTO
acid and majority of DBTO
of the catalyst, proving K
adsorption capacity for the oxidation products including DBTO
and octanoic acidwhich would affect the quality of the fuel oil.
To remove the residual DBTO and octanoic acid in the model
2
2 2
O
obtain peroxo-polyoxometalates with strong oxidized
characteristic, which could oxidize the sulfur compounds to
their correspondingsulfones, and acted as the real active
components. The mechanism in n-octanal/molecular oxygen
ODS system was proposed by Murata et al. In their work,
molecular oxygen could be activated by cobalt catalysts, and
the activeoxygen would react with aldehydes to obtainperoxy
acids which could oxidize the sulfur compounds to their
correspondingsulfones. Therefore, peroxy acids were the real
active components, and the molecular oxygen could not
directly react with aldehydes to obtainperoxy acids without
2
6
2
. As shown in figure. S2 (c), some octanoic
were observed in the MeCN eluent
62/GO had an excellent
2
6 2 18
P W O
2
o
cobalt catalysts at 40 C.
To analyzethe mechanism of the studied system, contrast
experiment was carried out and the results were given in Table
S3 (ESI). As shown in Table S3, the final desulfurization ratio
was 48.05% treated by extraction without ODS process. When
oil, 60 mlMeCNwas added in theoriginal model oil to form a bi-
phase system. The ODS reaction was still carried out as
described in section 2.4. The ODS curve was given in Figure.
1
4.
the air was bubbled into the system but no K
6
[α-
P
2
W
18
O
62]·14H Oorn-octanal were added, no obvious increase
2
8
| J. Name., 2012, 00, 1-3
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6
in the desulfurization ratio was observed, indicating that DBT
could not be directly oxidized by air without catalyst. Once
[α-P 62]·14H O was added into the system, the
desulfurization ratio raised from 48.12% to 62.75%. Based on
View Article Online
DOI: 10.1039/C8NJ05896B
K
6
2 18
W O
2
2
8
the analysis in the reference,
we deduced thatperoxo-
polyoxometalates was obtained through the reaction of
polyoxometalates and molecular oxygen, acting as the real
active components for the oxidation of DBT. When n-octanal
was added into the system, the desulfurization ratio raised
from 48.12% to 67.13%. Differ from that reported in the
reference, 26 the ODS reaction occurred in the n-octanal/air
system without catalyst. Hence, we supposed thatsome of the
aldehydes could directly react with molecular oxygen to
obtainperoxy acids at 60 C, due to the increase of reaction
6 2 18 2
temperature. When both of K [α-P W O62]·14H O and n-
octanal were added into the system, an impressive model oil.
desulfurization ratio of 99.63% was achieved. Inspired by the
reference work, 26 we supposed that the result was not only
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
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6
7
8
9
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9
0
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o
Scheme 1.Schematic of supposed mechanism for oxidativedesulfurization of
caused by the simple superposition effect of
6
K [α-
Conclusions
2 18
P W O62]·14H O and n-octanal. K [α-P 62]·14H O might
2
6
2 18
W O
2
In this work, three polyoxometalateswere successfully
prepared and used as the catalysts for ODS.Among which,
exhibited the best performance,
corresponding to 99.63% of desulfurization ratio. Furthermore,
2
O was supported on GO to obtain
P W O62/GO. Due to the high adsorption capacity of GO for
also act as the catalyst for the oxidation of n-octanal to obtain
more peroxy acids, thus promoting the ODS process. To
validate our hypothesis, another contrast experiment was
carried out and analyzed by GC method. In which, the
analytical sample was prepared by dissolving 20 wt% n-octanal
in the n-octane solvent. As shown in Figure S3 (ESI), some but
K
6
[α-P
2 18
W O62]·14H
2
O
K
K
6
[α-P
2
W
18
O62]·14H
6
2 18
ODS products, 96.10%of desulfurization ratio could be
achieved using the supported catalyst 17.5%-K [α-
62]·14H O, without extraction. According to the
experiment catalyzed by
62/GO, 60 oC was
not
acidwithoutcatalyst. However, nearly all of n-octanal were
oxidized, when K [α-P 62]·14H O was added in the
system. The result proved thatK [α-P 62]·14H O had the
all
ofn-octanal
was
oxidized
to
octanoic
6
2 18
P W O
2
6
2
W
18
O
2
6 2 18
K P W O
6
2 18
W O
2
determined as the optimum reaction temperature and the
supported catalyst was suitable for the model oil with a broad
range of initial sulfur contents. Besides, the reaction activity
sequence of different sulfur compounds was as DBT>4.6-
DMDBT>BT, determined by the electron density and space
steric hindrance on S atom. The experiment of selectivity
showed that the desulfurizationratio decreased from 96.10%
to 43.25% and 24.10%, when n-octylene and xylene were
added into the model oil, respectively, which might be caused
by the competitive oxidation. When treated by extraction of
MeCN, the desulfurizationratio could increase from 43.25%
and 24.10% to 94.31% and 84.45%, respectively. Therecovery
experiment showed that the supported catalyst could be
reused at least for 5 times with little catalysis deactivation.
catalytic performance for the oxidation of n-octanal, thus
obtaining more peroxy acids to promote the ODS process.
Through the above analysis, the studied ODS system was
considered as a complex system consisting of the multi-
oxidation of sulfur compounds by the action of prepared
catalyst andn-octanal.The proposed mechanism was illustrated
6 2 18 2
in Scheme 1: first, K [α-P W O62]·14H O reacted with
molecular oxygen to obtainperoxo-polyoxometalates, and
some of n-octanal also reacted with molecular oxygen to
obtain peroxy acids. Then, more peroxy acids was obtained
6 2 18 2
through the catalytic effect of K [α-P W O62]·14H O. Finally,
the peroxo-polyoxometalates and peroxy acids acted as the
real active components to oxidize the sulfur compounds to
their correspondingsulfones, and the sulfones were removed
through the adsorption of supported catalyst or extraction.
Compared with previous study, K
much better performance than GO in the n-octanal/air ODS
system due to the introduction of K 62. Finally, the
6 2 18
P W O62/GO exhibited
6 2 18
P W O
mechanism was proposed, and the studied ODS system was
considered as a complex process consisting of the multi-
oxidation of sulfur compounds by the action of prepared
catalyst andn-octanal.
Conflicts of interest
There are no conflicts to declare.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 9
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J. Zhang,A.Wang,X.Li andX.Ma.J. Catal.View20Ar1ti1cl,e O2nl7in9e
Acknowledgements
(
2),269.
30 M.
andC.Rabia.J. Mol. Catal. A: Chem.2016,414,72.
31 L. Saher,M.Makhloufi-
DOI: 10.1039/C8NJ05896B
Financial support from the National Natural Science
Foundation of China (No. 20976097; 21076116; 21311120297),
PetroChina Innovation Foundation (2010D-5006-0405), and
the Natural Science Foundation of Shandong Province, China
Moudjahed,L.Dermeche,S.Benadji,T.Mazari
Chebli,L.Dermeche,B.Boutemeur-
Khedis,C.Rabia,A.M.Silva
andM.Hamdi.Tetrahedron
(No. ZR2018MEE048), are gratefully acknowledged.
Lett.2016, 57(13),1492.
3
2
G. Zhang,B.Keita,C.T.Craescu,S.Miron, P.de Oliveira
andL.Nadjo.Biomacromolecules 2008, 9(3),812.
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9
0
33 F.
Martin.Energy Fuels2017, 31 (5),5419.
F. Banisharif, M.R.Dehghani,M.C.Capel-Sanchez
andJ.M.Campos-Martin. J.Ind. Eng. Chem. 2017,
7,348.
F. Banisharif,M.R.Dehghani,M.Capel-Sanchez
andJ.M.Campos-Martin. Ind. Eng. Chem. Res. 2017,
6(14),383.
Y. Gao,R.Gao,G.Zhang,Y.Zheng andJ.Zhao. Fuel2018,
24, 261.
Banisharif,M.R.Dehghani
andJ.M.
Campos-
References
1
2
3
4
5
6
J.A.Ford,J.Steen and M.L.Verreynne, J. Clean. Prod.
014, 84, 204.
A.B.Jaffe,R.G.Newell and R.N.Stavins.Ecol.Econ. 2005,
54 (2-3), 164.
P.Brijesh and S.Sreedhara.Int. J. Auto. Tech-Kor.
3
3
4
5
2
4
2
013,14(2), 195.
5
N. B.Suryawanshi, V. M. Bhandari, L. G.Sorokhaibam
3
3
6
7
and V. V. Ranade. Fuel 2017, 210, 482.
2
S.Y.
Dou
andR.Wang. Curr.
Org.
L. G.Sorokhaibam, V. M. Bhandari, M. S.Salvi, S.Jain, S.
D.Hadawale and V. V. Ranade. Ind. Eng. Chem. Res.
2015, 54(47), 11844-11857.
Chem. 2017,21(11),1019.
A. M.Kermani, A. Ahmadpour, T. R.Bastami,
M.Ghahramaninezhad. New J. Chem. 2018, 42(14),
3
3
4
8
9
0
R.T.Yang,
A.J.Hernández-Maldonado
1
2188.
andF.H.Yang. Sci. 2003, 301(5629),79.
Y.Zhang,D.Liu,L.Zhou,M.Tang,X.Li
Yang. Fuel2018, 216, 10.
7
L.Dong, H.Dong,T.Fujita,Y.Geng andM.Fujii. J. Clean.
Prod. 2015, 90, 345.
X.Liu,B.Lin andY.Zhang. J. Clean. Prod. 2016, 113, 133.
S.K.Bej.Fuel. Process. Technol. 2004,85(13), 1503.
Z. Hajjar,M. Kazemeini,A. Rashidi andS.Soltanali. J
Taiwan Inst Chem E 2017,78, 566.
andY.
A.
8
9
1
G.I. Danmaliki,A.S.TawfikandA.S.Abdullahi. Chem. Eng.
J.2017, 313, 993.
0
1
4
4
1
2
T.A. Saleh. J. Clean. Prod. 2018, 172, 2123.
R.
Menzel,
1
L. van Haandel,G.M.Bremmer,E.J.M.Hensen, and
T.Weber.J. Catal. 2017, 351,95.
D.Iruretagoyena,Y.Wang,S.M.Bawaked,M.S.Mokhtar,A.
Al-Thabaiti,S.N.Basahel andM.S.Shaffer. Fuel 2016, 181,
12 L.
Yang,X.Z.Wang,
Y.Liu,
Z.F.Yu,J.J.Liang,
5
31.
B.B.Chen,C.Shi,S.Tian,X.Li and J.S.Qiu. Appl. Catal.,
B 2017, 200, 211.
43 T.C. Chen, J.F.J.F.Sapitan,F.C.Ballesteros Jr, M.C.Lu. J.
Clean. Prod.2016,124, 378-382.
1
3
P.Huang, A.Liu, L.Kang, M.Zhu andB.Dai. New J.
Chem. 2018, 42(15), 12830.
4
4
Y. Yang,G.Lv,L.Deng,B.Lu, J. Li,J.Zhang,J.Shi andS.Du. J.
Clean. Prod.2017, 161, 422.
Y. Zhang andR.Wang.Diamond. Relat. Mater.2017,
14 R.Liu,Y.Zhang,J.Ding,R.Wang
Technol. 2017, 174,84.
andM.Yu.Sep.
Purif.
4
5
7
3,161.
1
5
L.Zhu, X.Jia, H.Bian, T.Huo, Z. Duan, Y.Xiang and D.
Xia. New J. Chem. 2018, 42(5), 3840.
46 R.G. Finke,M.W.Droege andP.J.Domaille.Inorg. Chem.
987, 26 (23),3886.
R.G. Finke,B.Rapko,R.J.Saxton andP.J.Domaille. J. Am
Chem. Soc. 1986,108 (11),2947.
C. Chen,Q.Wang,P.Lei,W.Song,W.Ma
andJ.Zhao. Environ. Sci. technol.2006,40(12), 3965.
1
1
6
C. Shen,Y.J.Wang, J.H.Xu andG.SLuo.Green. Chem.2016,
4
4
7
8
1
8(3),771.
.
17 S.Wei,H.He,Y.Cheng,C.Yang, G.Zeng, L.Kang,H.Qian
andC.Zhu.Fuel 2017, 200, 11.
J.W. Ding andR.Wang.Chin. Chem. Lett. 2016, 27
1
1
8
9
49 Y.
Zhu,S.Murali,
W.Cai,X.Li,J.W.Suk,J.R.and
(
5),655.
R.S.Potts.Adv.Mater.2010,22(35),3906.
N.Y. Chan,T.Y.Lin andT.F.Yen.Energy Fuels2008,
5
5
0
1
Y.P. Wang,B.B.Zhou andL.Y.Liu. J Alloys Compd2008,
2
2(5),3326.
4
63(1-2),333.
20 X.Ma,A.Zhou andC.Song.Catal. Today 2007,123(1-
R.I.Maksimovskaya. Russ.J.Inorg. Chem.1998, 43(12),
4),276.
1
825.
2
2
1
2
Y. Wu,P.Wu,Y. Chao,J.He,H.Li,L.Lu,W.Jiang,B.Zhang,H.Li
andW.Zhu.Nanotechnology 2017, 29(2),025604.
M. Shi,D.Zhang, X.Yu,Y.Li,X.Wang andW.Yang.Fuel.
Process. Technol. 2017, 160, 136.
52 Y.Zu,J.Tang,W.Zhu,M.Zhang,G.Liu,Y.Liu,W.Zhang
andM.Jia.Bioresour.Technol. 2011, 102, 8939-8944.
5
3
L.
Geng,S.Wu,Y.Zou,M.Jia,
W.Zhang,W.Yan
andG.Liu. J.Colloid Interface sci.2014, 421, 71-77.
23 W. Zhang,H.Zhang,J.Xiao,Z.Zhao,M.Yu andZ.Li. Green.
Chem. 2014,16(1), 211.
2
4
F.
Li,Y.Liu,Z.M.Sun,Y.Zhao,R.H.Liu,L.J.Chen
andD.S.Zhao.Catal. Sci. Technol.2012, 2(7),1455.
F. Lin,D.Wang,Z.Jiang,Y.Ma,J.Li,R.Li andC.Li.Energ.
Environ. Sci. 2012, 5(4), 6400.
2
5
26 S.
Fuels2004, 18 (1),116.
E. Rafiee and S.Rezaei. J Taiwan Inst Chem E 2016,61,
74.
R. Wang,F.Yu,G.Zhang and H.Zhao.Catal. Today2010,
50 (1-2),37.
Murata,K.Murata,K.Kidena
andM.A.Energy
2
2
7
8
1
1
1
0 | J. Name., 2012, 00, 1-3
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