Temperature-controlled selectivity in oxidation of 1-octene by using aqueous hydrogen peroxide in phase-boundary catalytic system

Article abstract of DOI:10.1016/j.apcata.2013.04.016

Temperature-controlled selectivity in oxidation of 1-octene by using aqueous hydrogen peroxide in phase-boundary catalytic system was demonstrated by using alkylsilylated-Ti(IV) salicylaldimine complex at a series of temperature (25-90 C). The catalyst was synthesized by titanium(IV) sulfate solution, salicylaldehyde, and 3-aminopropyltrimethoxysilane as the precursors and followed by the attachment of octadecyltrimethoxysilane. It was found that the reaction system resulted in high selectivity at low temperature. One suggests that the high selectivity in the oxidation of 1-octene by aqueous hydrogen peroxide was related to partitioning of alkylsilylated-titanium(IV) salicylaldimine complex in immiscible liquid-liquid phase boundary which is temperature dependent.

Full text of DOI:10.1016/j.apcata.2013.04.016

Applied Catalysis A: General 460–461 (2013) 21–25
Contents lists available at SciVerse ScienceDirect
Applied Catalysis A: General
journal homepage: www.elsevier.com/locate/apcata
Temperature-controlled selectivity in oxidation of 1-octene by using
aqueous hydrogen peroxide in phase-boundary catalytic system
Lai Sin Yuana, Rasidah Razalia, Jon Efendia,b, Nor Aziah Buanga, Hadi Nura,∗
a Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, Skudai 81310, Johor, Malaysia
b Department of Chemistry, Universitas Negeri Padang, Jl. Prof. Hamka, Air Tawar, Padang, West Sumatera, Indonesia
a r t i c l e i n f o
a b s t r a c t
Article history:
Temperature-controlled selectivity in oxidation of 1-octene by using aqueous hydrogen peroxide in
phase-boundary catalytic system was demonstrated by using alkylsilylated-Ti(IV) salicylaldimine com-
plex at a series of temperature (25–90 ◦C). The catalyst was synthesized by titanium(IV) sulfate solution,
salicylaldehyde, and 3-aminopropyltrimethoxysilane as the precursors and followed by the attachment
of octadecyltrimethoxysilane. It was found that the reaction system resulted in high selectivity at low
temperature. One suggests that the high selectivity in the oxidation of 1-octene by aqueous hydrogen
peroxide was related to partitioning of alkylsilylated-titanium(IV) salicylaldimine complex in immiscible
liquid–liquid phase boundary which is temperature dependent.
Received 21 November 2012
Received in revised form 2 March 2013
Accepted 12 April 2013
Available online 25 April 2013
Keywords:
Phase-boundary catalysis
Oxidation
Immiscible liquid–liquid
Temperature-controlled selectivity
Alkylsilylated-Ti(IV) salicylaldimine
complex
© 2013 Elsevier B.V. All rights reserved.
1. Introduction
the system. It can be deduced that amphiphilic structure is signifi-
cant in relation to the catalytic behavior.
Nowadays, heterogeneous liquid-phase which is involving
immiscible liquid–liquid phase and solid catalyst is widely utilized
in chemical processing and for environmental control. Cosolvent
and stirring are adopted in the catalytic system in order to gener-
ate homogeneous solution (biphasic condition) which can enhance
the interaction among reactants and solid catalyst. However, cosol-
vent brings the problem to the separation of the products from the
mixture of reactants and cosolvent. Besides, leaching effect and pro-
ducing unnecessary byproducts might be obtained after stirring.
Thus, phase-boundary catalysis (PBC) has been proposed with the
aim of solving the above problems with neither stirring nor adding
cosolvent in this triphasic condition [1–4].
Previously, phase-boundary catalysis (PBC) system with titania
impregnated on sodium zeolite solid particles along with surface
modified by octadecyltrichlorosilane (OTS) to form amphiphilic
structure solid particles has been reported [1–4]. The catalyst is
located in between the interphase of organic and aqueous phases
and then generates the mass transfer from bulk reactants to the
catalysts, resulting in high affinity for both 1-octene and aqueous
hydrogen peroxide, followed by improving the rate of reaction of
On the other hand, numerous heterogeneous transition metal
Schiff base complexes have been used in the epoxidation or oxida-
tion of olefins [5–7] by utilization of hydrogen peroxide. Aqueous
hydrogen peroxide (H2O2) is highly adopted due to it gives water
as byproduct, more accessible, and less expensive compared to
other oxidizing agents, such as organic peracids or hydroperoxides.
Moreover, the challenging and common phenomenon of nowa-
days is the conversion of organic substrate is very high, but, the
selectivity to products is quite low [8].
Herein, we would like to demonstrate the temperature-
controlled selectivity in oxidation of 1-octene by using aqueous
hydrogen peroxide (H2O2) in phase-boundary catalytic system by
using alkylsilylated-Ti(IV) salicylaldimine complex as catalyst. It is
worth noting that the selectivity to 2-octanone and 2-octanol was
quite high up to a point although the reaction was carried out at
high temperature at certain time.
2. Experimental
2.1. Synthesis of alkylsilylated-Ti(IV) salicylaldimine complex
The synthesis of Ti(IV) salicylaldimine complex was done in
the following steps. Ti(IV) sulfate solution (1.0 mmol, 0.89 ml,
Kanto Chemical) in absolute ethanol (10 ml, Hayman) was added
dropwise into salicylaldimine ligand (2.0 mmol, 0.57 g) in absolute
∗
Corresponding author. Tel.: +60 7 5536162; fax: +60 7 5536080.
E-mail address: hadi@kimia.fs.utm.my (H. Nur).
URL: http://www.hadinur.com (H. Nur).
0926-860X/$ – see front matter © 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.apcata.2013.04.016

22
L.S. Yuan et al. / Applied Catalysis A: General 460–461 (2013) 21–25
ethanol (10 ml, Hayman). The ligand was previously prepared by
salicylaldehyde (5.0 mmol, 0.54 ml, Acros Organics) in absolute
ethanol (10 ml, Hayman) and 3-aminopropyltrimethoxysilane
(5.0 mmol, 0.96 ml, Aldrich–Sigma) in absolute ethanol (10 ml,
Hayman), both were mixed under flow of nitrogen gas and then
vacuumed to remove the solvent. The weight of ligand was
obtained before adding with Ti(IV) sulfate solution. After that, the
titanium(IV) mixture solution was stirred for 24 h to complete
the hydrolysis and condensation reaction. It was followed by
centrifugation of Ti(IV) salicylaldimine complex at 4000 rpm for
10 min to separate the solid complex and liquid layer (solvent)
in the solution. Then, the solid complex was washed by ethanol
and hexane, each for twice, to wash out the excess ligand and
water. The weight of Ti(IV) salicylaldimine complex was 0.71 g.
Now, the procedures for the synthesis of phase-boundary catalysts
were as follows. Ti(IV) complex (0.50 g) was ground with 0.25 ml
doubled distilled water thoroughly. After that, it was put into the
beaker containing octadecyltrimethoxysilane (OTMS, 500 ␮mol
per 1 g of solid Ti(IV) salicylaldimine complex, 0.12 ml, Merck) in
10 ml toluene. It was shaken for 5 min and stirred until dry for 3–4
days. Then it was washed by toluene and hexane, twice for each
solvent. This catalyst was known as phase-boundary catalyst. The
procedure to make phase-boundary solid particles was adopted
from the previous reports [1–4].
Fig. 1. FTIR spectra of (a) Ti(IV) salicylaldimine complex and (b) alkylsilylated-Ti(IV)
salicylaldimine complex.
The alkylsilylated–Ti(IV) complex (0.05 g) was examined at 25, 30,
40, 50, 60, 80 and 90 ◦C to observe the relationship of solubility and
temperature. We used the sealed and closed system in order to pre-
vent the evaporation of the reactants. The apparatus used is 10 ml
bottle sample with screw cap equipped with induction seal liner in
order to avoid leaking of the system.
The products of reaction were analyzed by Shidmazu Gas Chro-
matography model GC-2014 equipped with BPX-5 column (30 m
length, 0.25 mm inner diameter, 0.25 ␮m film thickness and a flame
ionization detector (FID). The catalytic reactions were conducted
without organic solvent. The program temperature of the column
oven was performed at the initial temperature, 50 ◦C, held for
1.0 min, ramp temperature is 10 ◦C min−1 till 200 ◦C and it was held
for 3 min to elute the products left. Total program time is 12.40 min.
The equilibration time is 1.0 min.
2.2. Characterizations of alkylsilylated-Ti(IV) salicylaldimine
complex
The solid catalysts obtained were characterized by Fourier
transform infrared (FTIR) spectrometer, diffuse reflectance
ultraviolet–visible spectrometer (DR UV–vis), scanning electron
microscope (SEM) and 29Si solid state magic angle spinning (MAS)
nuclear magnetic resonance NMR.
Samples were preheated at 60 ◦C for few hours as a precaution
step to ensure that the dried samples mixed well with KBr pow-
der and get a compact and transparent disk for infrared analysis.
The FTIR spectra were collected on a Perkin Elmer Spectrum One
spectrometer with 15 scans and resolution of 4 cm−1, in the range
of 4000–400 cm−1. Potassium bromide (KBr) pellet technique was
used to examine the presence of alkylsilyl groups on Ti(IV) sali-
cylaldimine complex after modified by octadecyltrimethoxysilane
(OTMS) (alkylsilylated-Ti(IV) salicylaldimine complex). The sam-
ples were mixed with KBr in the weight ratio of 1:100 and ground
thoroughly. Then, it was put in the pellet die to make a very thin
pellet for analysis.
3. Results and discussion
The result of IR spectra Ti(IV) salicylaldimine complex and
alkylsilylated-Ti(IV) salicylaldimine complex is presented in Fig. 1.
The solid Ti(IV) salicyladimine complex was successfully formed
because the imine group (C N) is at lower frequency, 1610 cm−1
,
compared to free azomethine group which was assigned at
1647 cm−1 [9]. In our infrared results, there are two absorption
bands have been assigned to Ti N and Ti O bonds with 601 cm−1
[10] and 697 cm−1 [11], respectively (Fig. 2).
The solid yellow samples were also recorded by Perkin Elmer
Ultraviolet-visible Spectrometer Lambda 900 and plotted using
Kubelka–Munk function, in the range of 200–800 nm, using barium
sulfate as the standard.
It is found that the stretching mode of Si OH functional group
at ca. 3427 cm−1 [11,12], meanwhile, its bending mode located
at 984 cm−1. However, Yan Luo et al. [13] suggested that this
The morphology of the solid particles was observed under low
vacuum scanning electron microscope (LVSEM). The solid particles
were fixed on carbon tape and then coated with platinum for 4–5
times under conventional sputtering techniques. Then, the sample
morphology was shown under 15 kV accelerating voltage.
The 29Si MAS NMR experiments were performed using Bruker
Avance 400 MHz 9.4T spectrometer. The spectra were recorded at
79.44 MHz using 4 ␮s radio frequency pulses, a recycle delay of 60 s
and spinning rate of 7.0 kHz using a 4 mm zirconia sample rotor. 29Si
MAS NMR chemical shifts were referred to external TMS at 0 ppm.
region frequency (984 cm−1) might be assigned to Ti
O
Si bonds.
The absorption bands presented at 1125 cm−1 and 1035 cm−1
are attributable to Si Si asymmetric and symmetric stretch-
O
ing modes, respectively [9]. We observed that OH bending from
water molecules at the 1661 cm−1 [14] for complexes due to the
complexes comprised of terminal silanol groups. This hydrophilic
silanol group, Si OH, can attract moisture containing water
molecules onto it.
Before the solid complex was modified by octade-
cyltrimethoxysilane (OTMS), there is no apparent peak at around
2920–2850 cm−1 and 1470–1460 cm−1. After the modification,
there are evident peaks shown by this phase-boundary catalyst
due to attachment of octadecylsilyl groups on the complexes,
hence, absorption bands of symmetric and asymmetric CH2 vibra-
tion at 2850 and 2918 cm−1 and CH2 bending peak at 1468 cm−1
and 1504 cm−1 were observed [15]. Furthermore, the peak at ca.
2.3. Catalytic activity of alkylsilylated-Ti(IV) salicylaldimine
complex
The reactions were carried out at a series of temperature to
investigate catalytic activities of oxidation of 1-octene (10 mmol,
1.56 ml, Merck) by 30% aqueous H2O2 (30 mmol, 3.06 ml, Merck).

L.S. Yuan et al. / Applied Catalysis A: General 460–461 (2013) 21–25
23
LMCT of C6H6O– to Ti4+
nitrogen from imine group has successfully coordinated to metal to
form complexes [19,20]. It is a typical electronic transition in transi-
tion metal Schiff base complexes which consist of the aromatic ring
association of n – π* of imine group
and octadecyltrimethoxysilane
and
C N imine conjugation (n–␲* transition) [20]. Furthermore,
we observed that the alkylsilylated-Ti(IV) salicylaldimine complex
displayed more intense absorption band at ca. 360 nm compared
to Ti(IV) salicylaldimine complex. It is because of the addition
of octadecyltrimethoxysilane (OTMS) to the metal complex. This
argument was supported by the previous reported literature [21].
29Si MAS NMR has been used for the structural characterization
of silica surface modification as described in Fig. 3. It is depicted
in Fig. 3 that the presence of T3 = R Si(OSi)3 with −66 ppm [22] in
the complex is due to hydrolysis and condensation of the alkylsi-
lylane group of Ti(IV) salicylaldimine complex. It can be seen that
the hydrolysis and condensation processes were completed with
high degree of cross-linking on the complexes. After anchoring the
octadecyltrimethoxysilane (OTMS) to the complexes, it is interest-
ing to note that the appearance of new signal at −57 ppm [22],
which is attributed to partial cross-linking with terminal silanol
groups, T2 = R Si(OH)(OSi)2. The results suggest that the OTMS has
been successfully attached on the complexes. Thus, this analysis
can be complementary to FTIR, diffuse reflectance UV–vis spectra
and SEM image in determining the proposed structure as shown
in Fig. 4b. The SEM micrograph displayed the particles are in small
sizes (ca. 100–700 nm) and this particles can be well-dispersed in
the consolute layer of the immiscible liquid–liquid system at 90 ◦C
after 24 h as depicted in Fig. 4a.
(a) alkylsilylated-Ti(IV) salicylaldimine
complex
LMCT of C6H6O– to Ti4+
n – π* of imine group
(b) Ti(IV) salicylaldimine complex
200 250 300 350
400 450 500 550 600 650 700 750 800
Wavenumber / nm
Fig. 2. Diffuse reflectance UV–vis spectra of (a) alkylsilylated-Ti(IV) salicylaldimine
complex and (b) Ti(IV) salicylaldimine complex.
818 cm−1 was attributed to symmetric deformation vibration of
Si C stretching [16].
In the diffuse reflectance of spectra Ti(IV) salicylaldimine
complex and alkylsilylated-Ti(IV) salicylaldimine complex, both
displayed that a shoulder band in the range of 200–250 nm, it
is owing to association of ␲–␲* transitions of aromatic ring and
imine (C N) group [17]. It is found that there is an absorption
at 315–317 nm because of Laporte – allowed LMCT of oxygen
from phenyl group (substituted phenol) to Ti(IV) was success-
fully formed [18]. Shifting of n–␲* transition of imine group,
Fig. 5a shows the phase-boundary catalyst was well suspended
and located at the immiscible liquid/liquid interface. Octadecylsi-
lyl group was partially attached onto the Ti(IV) salicylaldimine
complex to form hydrophobic Si
O R groups, on the other hand,
the complex is hydrophilic due to the presence of Si OH groups
after the hydrolysis and condensation process of salicylaldehyde
and 3-aminopropyltrimethoxysilane (APTMS). This amphiphilic
C
N (400 nm) [16] to lower frequency, ca. 360 nm, was due to the
O
O
Ti
HC=N
N=CH
T3 = –66 ppm
Si
Si
Ti(IV)
salicylaldimine
complex
silica
O
O
Ti
HC=N N=CH
T2 = –57 ppm
alkylsilylated-
Ti(IV)
Si Si
Si
HO
O
Si
Si
OH
0
HO
salicylaldimine
complex
silica
–50
ppm
–100
Fig. 3. 29Si MAS NMR spectra and proposed structures of Ti(IV) salicylaldimine complex.

24
L.S. Yuan et al. / Applied Catalysis A: General 460–461 (2013) 21–25
characteristic is such an advantage for the solid catalyst to be
located at the interphase of both organic and aqueous phase, and
thus, it can contact with both phases effectively. It is worth to
notice that the immiscible liquid–liquid boundary phase formed
consolute liquid layer at low temperature, however, it is near to the
upper consolute point (partially miscible) with increasing temper-
ature. It is clearly seen in Fig. 5a. According to Sinko [23], there are
three types of systems in describing the liquid–liquid solubility:
upper critical solution temperature (UCST), lower critical solution
temperature (LCST), last but not least, upper and lower critical solu-
tion temperature. Our reaction system can be categorized as upper
critical solution temperature (UCST) system. It is owing to organic
1-octene is partially miscible to aqueous hydrogen peroxide by
increasing the temperature to a certain extent. This consolute layer
gives effect to the conversion and selectivity of the reaction system.
Fig. 5b summarizes the product selectivity of the reac-
tion between 1-octene and aqueous H2O2 in the presence
of alkylsilylated-Ti(IV) salicylaldimine complex as the phase-
boundary catalyst. From previous research, 1,2-epoxyoctane was
the main product at room temperature with high selectivity [1,2],
however, in this reaction system; 2-octanone was the main prod-
uct instead. It might due to the concentration of hydrogen peroxide
adopted is higher than previous researches and the characteris-
tic of the catalyst system is different [1–4], which can trigger the
faster reactivity of the 1,2-epoxyoctane to open the oxirane ring
and then form 2-octanone. At higher temperature (60 ◦C), prod-
ucts of 2-octanol are predominant than others and it was observed
that selectivity to 2-octanone decreased with increasing of the
selectivity to 2-octanol along the temperature from 25–60 ◦C. One
suggests that the 2-octanone can act as a substrate to undergo fur-
ther oxidation reaction by aqueous hydrogen peroxide assisted by
the catalyst. To prove this argument, the oxidation of 2-octanone
with aqueous H2O2 was conducted at 25 and 90 ◦C as shown in
Table 1. It was observed that the yield of 2-octanol in the oxidation
reaction decreased when the temperature increased. It is because
2-octanone was converted to other products at higher tempera-
ture. It is in agreement with the results shown in the oxidation of
1-octene by aqueous H2O2 (Fig. 5b) over alkylsilylated-Ti(IV) salicy-
laldimine complex, in which the selectivity to 2-octanone decrease
with increasing temperature.
Fig. 4. (a) Photograph of the solid complex can be stabilized at the consolute
liquid–liquid phase boundary after 24 h at 90 ◦C and (b) SEM image of alkylsilylated-
Ti(IV) salicylaldimine complex.
On the other hand, it is an interesting phenomenon to note
that the conversion was maintained approximately in 15–18% with
duration of 1 h. Generally, the rate of reaction depends on the tem-
perature and concentration of reactants. Increasing temperature
and concentration of reactants will increase the frequency of col-
lisions between reactants and hence increasing the reaction rate
[24]. However, in our phase-boundary catalytic system, as shown
in Fig. 5a, increasing temperature will increase the consolute layer.
The presence of the consolute layer can reduce the concentra-
tion of reactants at the liquid–liquid interfacial layer at relatively
high temperatures. One suggests that although an increase in the
reaction rate, the concentration of reactants decreases at higher
temperatures. The compensation effect between increasing the
reaction rate and lowering the concentration of reactants in the
consolute layer at relatively high temperature is the reason why
the conversion of reactants is almost the same at low and high
Table 1
Catalytic oxidation of 2-octanone.a
Temperature (◦C)
The yield of 2-octanol (%)
25
90
6.7
3.7
Fig. 5. (a) The photograph of the consolute liquid–liquid layers increases with ele-
vating temperatures and (b) the conversion of 1-octene and the product yields of
2-octanone, 2-octanol, 1,2-epoxyoctane and other products after catalytic reaction.
The reactions were carried out for 1 h with 1-octene (10 mmol, 1.56 ml), 30% aqueous
H2O2 (30 mmol, 3.06 ml) and catalyst (50 mg) under static conditions.
a
The oxidation reaction was examined by 2-octanone (10 mmol, 1.56 ml), H2O2
30% (30 mmol, 3.00 ml), and 50 mg catalyst. It was carried out at the selected tem-
peratures, 25 and 90 ◦C for 1 h.

L.S. Yuan et al. / Applied Catalysis A: General 460–461 (2013) 21–25
25
90
80
70
60
50
40
30
20
10
0
due to the contact area between the reactant and catalyst is thor-
oughly increased, hence, it results in increasing of conversion and
reaction rate. Moreover, Table 2 displays that the reaction rates of
alkylsilylated-Ti(IV) salicylaldimine complex at a series of temper-
atures are ca. 3.30–4.12 mmol h−1. Hence, the selectivity can be
compared under the similar conversion percentage by varying the
temperatures. At 90 ◦C, the reaction rate is the highest amongst
all due to increase of liquid–liquid miscibility of 1-octene and
aqueous hydrogen peroxide or consolute phase-boundary layer.
Static
Stirring
Addition co-solvent
4. Conclusions
Temperature-controlled selectivity in oxidation of 1-octene by
using aqueous hydrogen peroxide in phase-boundary catalytic
system over alkylsilylated-Ti(IV) salicylaldimine complex catalyst
has been demonstrated. In conclusion, there are two properties
that make the selectivity of the oxidation of 1-octene by using
aqueous hydrogen peroxide can be temperature-controlled in
phase-boundary catalytic system. The first property is the presence
of catalyst that can be located at liquid–liquid boundary. Secondly,
the ability of the catalyst to well-disperse and stabilize after 24 h
at 90 ◦C in the consolute layer of the liquid–liquid phase due to an
increase in the miscibility between organic and aqueous phases at
relatively high temperature.
Fig. 6. The effects of static, stirring and adding cosolvent in the phase-boundary
catalytic system at 25 ◦C. Reaction conditions are the same as given for Fig. 4. To
examine the effect of cosolvent, the homogeneous mixture was made. It contains
1-octene (8%), aqueous H2O2 (8%), ethanol (84%) and catalyst (50 mg).
Acknowledgments
temperatures. Due to the products from oxidation of 1-octene, i.e.
2-octanone, 2-octanol and 1,2-epoxyoctane, are more hydropho-
bic than aqueous H2O2 and more hydrophilic than 1-octene, one
suggests that they can easily dissolve in the consolute layer which
is also more hydrophilic and hydrophobic compared with 1-octene
and aqueous H2O2, respectively. It suggests that the consolute layer
can act as a medium for the reaction products to react with the cat-
alyst to produce other products. Subsequently, it has resulted in
low selectivity.
Furthermore, it is widely known that the cosolvent can greatly
influence the conversion and selectivity in a reaction system [25],
however, Fig. 6 proves that vigorous stirring and addition of ethanol
as cosolvent in this system do not give much effect to the selectivity.
The reaction solution included homogeneous mixture containing
1-octene (8%), aqueous H2O2 (8%), ethanol (84%) and catalyst
(50 mg). The selectivity to 2-octanone at 25 ◦C is 67% and 61% for
stirring and adding cosolvent, respectively. The obtained results
were near to the selectivity of 2-octanone by phase-boundary catal-
ysis, i.e. 79%. However, the conversion increased remarkably for
both conditions, which vigorous stirring resulted in 64% conversion
and addition of cosolvent produced 72% conversion. It is reasonable
The authors gratefully acknowledge the Ministry of Higher Edu-
cation (MOHE), Malaysia through Fundamental Research Grant
Scheme, Universiti Teknologi Malaysia through Research Univer-
sity Grant, and MyPhD scholarship (MyBrain 15 Program) by
Ministry of Higher Education Malaysia under 10th Malaysia Plan.
References
[1] H. Nur, S. Ikeda, B. Ohtani, Chem. Commun. 22 (2000) 2235–2236.
[2] H. Nur, S. Ikeda, B. Ohtani, J. Catal. 204 (2001) 402–408.
[3] H. Nur, S. Ikeda, B. Ohtani, React. Kinet. Catal. Lett. 82 (2004) 255–261.
[4] H. Nur, S. Ikeda, B. Ohtani, J. Braz. Chem. Soc. 15 (5) (2004) 719–724.
[5] Y. Yang, J. Guan, P. Qiu, Q. Kan, Appl. Surf. Sci. 256 (2010) 3346–3351.
[6] N. Malumbazo, S.F. Mapolie, J. Mol. Catal. A: Chem. 312 (2009) 70–71.
[7] L. Saikia, D. Srinivas, P. Ratnasamy, Appl. Catal. A 309 (2006) 144–154.
[8] M.R. Maurya, U. Kumar, P. Manikandan, Eur. J. Inorg. Chem. (2007) 2303–2314.
[9] Y. Yang, S. Hao, P. Qiu, F. Shang, W. Ding, Q. Kan, React. Kinet. Mech. Catal. 100
(2010) 363–375.
[10] K. Nakamoto, Infrared and Raman Spectra of Organic and Coordination Com-
pounds, 4th ed., John Wiley and Sons, Hoboken, NJ/Canada, 1986.
[11] L.S. Yuan, J. Efendi, N.S.H. Razali, H. Nur, Catal. Commun. 20 (2012) 85–88.
[12] K.M. Parida, S. Singha, P.C. Sahoo, Catal. Lett. 136 (2010) 155–163.
[13] Y. Luo, G.Z. Lu, Y.L. Guo, Y.S. Wang, Catal. Commun. 3 (2002) 129–134.
[14] T. Lopez, E. Sanchez, P. Bosch, Y. Meas, R. Gomez, Mater. Chem. Phys. 32 (1992)
141–152.
[15] M.L. Pe˜na, V. Dellarocca, F. Rey, A. Corma, S. Coluccia, L. Marchese, Microporous
Mesoporous Mater. 44–45 (2001) 345–356.
[16] S. Photong, V. Boonamnuayvitaya, Water Air Soil Pollut. 210 (2010) 453–461.
Table 2
Reaction rates of the oxidation of 1-octene.a
´
[17] E. lspir, Phosphorus Sulfur Silicon Relat. Elem. 184 (2009) 3160–3174.
Entry
Temperature (◦C)
Reaction rateb (mmol h−1
)
[18] C. Hu, W. Zhang, Y. Xu, H. Zhu, X. Ren, C. Lu, Q. Meng, H. Wang, Transit. Met.
Chem. 26 (2001) 700–703.
1
2
3
4
5
6
7
8
25
30
40
50
60
70
80
90
3.3
3.7
3.3
3.4
3.2
3.0
3.4
4.1
[19] G.B. Roy, Inorg. Chim. Acta 362 (2009) 1709–1714.
[20] K.M. Parida, M. Sahoo, S. Singha, J. Catal. 276 (2010) 161–169.
[21] C.A. García-González, A.R. Sampaio da Sousa, A. Argemí, A. López
Periago, J. Saurina, C.M.M. Duarte, C. Domingo, Int. J. Pharm. 382 (2009)
296–304.
[22] H. Nur, N.Y. Hau, M.N.M. Muhid, H. Hamdan, Phys. J. IPS A7 (2004) 218.
[23] P.J. Sinko, Martin’s Physical Pharmacy and Pharmaceutical Sciences: Physi-
cal Chemical Principles in the Pharmaceutical Sciences, 5th ed., Lippincott
Williams & Wilkins, Philadelphia, 2006.
[24] A. Zanardo, F. Pinna, R.A. Michelin, G. Skrukul, Inorg. Chem. 27 (1988)
1966–1973.
[25] B.P. Binks, T.S. Horozov, Colloidal Particles at Liquid Interphases, 1st ed., Cam-
bridge University Press, New York, 2006.
a
The reaction was conducted at 1 h with the oxidation 1-octene (10 mmol,
1.56 ml), H2O2 30% (30 mmol, 3.00 ml), and 50 mg catalyst.
b
Reaction rate is the average rate of a reaction over a time interval by dividing
the change in concentration of products over that time period by the time interval.