Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene
The study is devoted to ESR-investigation of the primary processes upon chemisorption of benzene molecules onto the molybdenum supported on dispersed SiO2 and TiO2 samples. It has been confirmed that benzene chemisorption onto the Mo6+ species results in one-electron transfer in the ground state and...
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Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine
2002
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|---|---|
| author | Ignatovych, M. Teslenko, V. Eremenko, A. Ogenko, V. Chuiko, A. |
| author_facet | Ignatovych, M. Teslenko, V. Eremenko, A. Ogenko, V. Chuiko, A. |
| author_institution_txt_mv | [
{
"author": "M. Ignatovych",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "V. Teslenko",
"institution": "Institute of Semiconductor Physics of National Academy of Sciences"
},
{
"author": "A. Eremenko",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "V. Ogenko",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "A. Chuiko",
"institution": "Інститут хімії поверхні НАН України"
}
] |
| author_sort | Ignatovych, M. |
| baseUrl_str | |
| collection | OJS |
| datestamp_date | 2018-11-27T09:42:19Z |
| description | The study is devoted to ESR-investigation of the primary processes upon chemisorption of benzene molecules onto the molybdenum supported on dispersed SiO2 and TiO2 samples. It has been confirmed that benzene chemisorption onto the Mo6+ species results in one-electron transfer in the ground state and paramagnetic species formation, namely reduced molybdenum species (Mo5+ species) and radicals of benzene. Computer treatment of ESR experimental data revealed that there are several types of Mo5+ species and benzene radicals, the assignment of which is proposed. |
| first_indexed | 2025-07-22T19:30:10Z |
| format | Article |
| fulltext |
115
Surface chemistry of silica and related sorbents
ELECTRON SPIN RESONANCE STUDY
ON Mo-SiO2 AND Mo-TiO2 WITH ADSORBED BENZENE
M. Ignatovych1, V. Teslenko2, A. Eremenko1, V. Ogenko1, and A. Chuiko1
1Institute of Surface Chemistry, National Academy of Sciences
Gen.Naumov Str.17, 03680 Kyiv-164, UKRAINE
2Institute of Semiconductor Physics, National Academy of Sciences
Prospect Nauky 45, 03028 Kyiv, UKRAINE
Abstract
The study is devoted to ESR-investigation of the primary processes upon chemisorption
of benzene molecules onto the molybdenum supported on dispersed SiO2 and TiO2 samples. It
has been confirmed that benzene chemisorption onto the Mo6+ species results in one-electron
transfer in the ground state and paramagnetic species formation, namely reduced molybdenum
species (Mo5+ species) and radicals of benzene. Computer treatment of ESR experimental data
revealed that there are several types of Mo5+ species and benzene radicals, the assignment of
which is proposed.
Introduction
During several decades molybdenum species (Mo-species) supported on different oxide
carriers by various preparation methods are extensively studied by a multitude of the
spectroscopic techniques because of prominent catalytic and photocatalytic properties of such
materials [1-6]. Comprehensive investigations aimed at preparation and spectroscopic
characterization have been reported by many research groups [7-10]. It is well documented
that many efforts have already been made to prepare the samples with Mo-species -
well-defined, highly dispersed, and of a certain local structure [3, 4, 7]. However, in the most
cases in the materials obtained just several kinds of Mo-species of different oxidation,
coordination and dispersion states coexist even at low Mo loadings [9, 11, 13]. ESP techniques
was widely used and proved to be very informative for detailed characterization of reduced
Mo-species, in particular, Mo5+-complexes [7-9, 12, 13].
This investigation have been stimulated by our previously performed studies on
electron-transfer and charge-transfer complexes formation upon chemisorption of arene
molecules – naphthalene (Nph), anthracene (An) and perylene (Py) onto silica or
zeolites [14, 15]. It has been shown with by ESR and photoluminescence techniques that
oxidation of Nph and An with cation radicals generation requested UV-irradiation. Only Py,
which has the lowest ionization potential, is oxidized to cation radicals directly upon
chemisorption. However, mere exposure of these molecules onto fully oxidized Mo6+-SiO2
surfaces at room temperature resulted immediately in aromatic radicals and reduced
Mo5+-species formation. Thus, one-electron redox process on the Mo-SiO2 surfaces was
confirmed and monitored directly by ESR [16].
116
The present paper is an attempt to study in more details the nature of radicals generated
upon interaction of electron-donating molecules with supported Mo-species. Interaction of
benzene (Bz) molecules with Mo-species supported on SiO2 and TiO2.was studied by ESR
technidues complemented with computer treatment.
Experimental
Sample preparation and trearment. Molybdenum-containing samples were prepared
using two methods:
i) conventional impregnation technique using an aqueous solution of ammonium
heptamolybdate;
ii) grafting of MoCl5 (in CCl4 solution) onto dehydrated at 873K supports under dry nitrogen
conditions (as in [9]). For sample preparation highly dispersed fumed silica and titanium oxide
have been used (with specific surface area 200 and 120 m2/g respectively). As-prepared
impregnated samples were dried at 393K. Grafted samples were twice washed with CCl4, then
hydrolyzed in the water vapor for 8 hours and dried in N2 at 393K. Hydrolyzed samples had
blue color.
All the samples were subsequently oxidized in O2 flow for 6 hours at 673K. After this
treatment both type of samples became almost white, evidencing that the most of Mo atoms
were oxidized to Mo6+. The Mo-loading was in the range of 1-5 wt. %. As within this Mo
concentration range the experimental results were basically the same, in the paper the samples
will be regarded with 3.0 wt. % for impregnated and 3.6 wt. % for grafted specimens.
Hot oxidized samples were transferred for thermoevacuation and interaction with
benzene to vacuum-spectral cell. This cell had attached ESR tubes and ampoule with
benzene (Bz) previously deoxygenated by freeze-pump-thaw technique. After
thermoevacuation (for 3 hours at 673K) one part of sample was transferred to ESR tube that
was then sealed under vacuum. The sample remaining in the cell, after cooling to room
temperature, was exposed for several minutes to Bz vapors (the excess of Bz vapor being then
evacuated at room temperature) and also transferred to ESR tube. Thus, ESR spectra were
taken of the samples kept in the sealed under vacuum ESR tubes.
ESR measurement. Spectra were recorded at 300 and 77K with SEX-2543
spectrometer (Radiopan). Experimental g-values were determined by direct measurements of
the frequency and magnetic field. For computer simulation of ESR spectra the programs
WINEPR and SIMFONIA (Bruker) were used.
Results and discussion
Figs. 1 and 2 represent respectively the typical experimental spectra of Mo-SiO2 and
Mo-TiO2 samples. In the both cases the a-signals relate to thermoevacuated and b-signals - to
the samples after Bz vapor sorption. It is important to note that in the blank experiment pure
supports SiO2 and TiO2 have not exhibited ESR signals neither for thermoevacuated samples,
nor for those ones after exposure with Bz. Thus, it is clear that ESR signals presented in the
Figs. 1 and 2 should be related to Mo-species (spectra a) and their interaction with Bz
(spectra b). Also it should be indicated that the receiver gain for recording of spectra in Fig. 1
is 10 times greater, than that in Fig. 2.
The temperature independence of line shape and the magnitude of g-values of 1a and 2a
signals that arose upon thermoevacuation at 673K strongly pointed to the presence of reduced
Mo5+-species. The local structure of Mo5+-species will be discussed in more details later, but
now worthwhile pay an attention to different reducibility of Mo-species, supported on SiO2 and
117
TiO2. Intensity of Mo5+-signal (see Fig. 2, a) is almost one order larger than signal (Fig. 1, a) at
practically the same Mo-loading for Mo-SiO2 and Mo-TiO2 samples.
Exposure of thermoevacuated samples to Bz vapor resulted in the following:
i) the appearance of new narrow singlet signal in the free-electron region that was similar
for both samples (spectra 1b and 2b);
ii) the remarkable increasing of Mo5+ signal for Mo-SiO2 samples.
3 3 0 3 4 0 3 5 0 3 6 0 3 7 0
E
PR
a
m
pl
itu
de
, a
.u
.
1 .9 4 62 .0 0 2 3
b )
a )
m ag n e tic fie ld , m T
Fig. 1. Experimental ESR spectra of Mo-SiO2 samples registered at 77K:
a - thermoevacuated sample; b – after exposure in benzene vapor.
The receiver gain for registration signals is 0.5´103.
320 330 340 350 360 370
E
PR
am
pl
itu
de
,
a.
u.
1.91 1.875
1.945
2.0023
b)
a)
magnetic field, mT
Fig. 2. Experimental ESR spectra of Mo-TiO2 samples registered at 77K:
a - thermoevacuated sample; b - after exposure in benzene vapor.
The receiver gain for registration signals is 5´103.
118
The appearance of new singlet ESR signals in the free-electron region is a quite
common feature, observed in the numerous studies at interaction of organic electron-donating
molecules with the solids, which possessed electron-accepting properties. It is usually assigned
to cation radicals [17].
Previously we also observed very similar intensive narrow singlet signals with
g=2.0025 and g=2.0029, developed at interaction of Mo-SiO2 samples with aromatic
molecules - naphthalene and anthracene, respectively [14]. It is worth to note that the
intensities of these singlets were significantly larger as compared with intensities developed
upon Bz interaction, that is in good agreement with the ionization potentials of these
molecules. Thus, it seems quite reasonable to assume one-electron oxidation of adsorbed Bz
molecules leading to Bz radicals generation.
Fig. 3 demonstrates the line shape simulation of the experimental signals in
free-electron region for Mo-SiO2 sample, recorded at 300K (curves 1 and 1a) and at 77K
(curves 2 and 2a).
Fig. 3. Integrated form of ESR spectra for Mo-SiO2 sample in the free-electron region:
1 – registered at 300K; 2 – at 77K (1a and 2a are experimental spectra,
1b and 2b are approximations by Gauss singlets).
The asymmetric single signal recorded at 300K may be satisfactorily approximated by
two Gaussian curves with such widths as 0.59 and 1.18 mT (Fig. 3, curves 1 and 1a). The line
shape of the signal recorded at 77K is more complicated, i.e. experimental signal is
approximated by three Gaussian curves with the following widths – 1.04, 1.42 and 3.1 mT
(Fig. 3, curves 2 and 2a). It is important to note that each of them is broader than the
corresponding curves recorded at 300K. Results concerning Mo-TiO2 sample are rather similar
as it is seen from data of Table. Line shape analysis of Bz-radicals experimental signal revealed
the superposition of individual Gauss-shape singlets with slight difference of g-values but
noticeable difference of width (DH). Results of line shape simulation of Bz-radicals signal are
expressed as appropriate parameters of centers 1, 2, and 3 in the Table.
Thus, two types of Bz radicals (for Mo-TiO2 ) and three types of them (for Mo-SiO2)
should be considered at benzene interaction, but further specification can not be done because
resolved spectra with hyperfine structures are lacking. But it deserves to explain the possible
2a
2 b
1 a
1 b
m a g n e t ic f ie l d , m T
3 2 8 3 3 0 3 3 2
119
reasons of it. Available numerous data, discussed in the comprehensive review[17], give
evidence that:
i) singlet signals with g~2.00, as a rule, were observed when benzene molecule (or
other electron donors) were adsorbed from the vapor phase;
ii) resolved spectra with hyperfine structure of Bz or other aromatic adicals
succeeded to detect after contact of diluted solution with microporous materials;
iii) the primary Bz radical C6H6
+ very quickly undergoes the subsequent
transformations and rearrangements that lead to biphenyl radical, then to more stable
polyphenyl species, that displays the singlet signals.
We can also speculate about other possible reasons such as:
iv) anisotropic broadening:
Preliminary we showed that the broadening (more than 0.4 mT) of individual
components of 7-component primary cation Bz-radical spectrum causes unresolved singlet
lineshape.
v) restriction of motion due to adsorption on surface and interaction with neutral Bz
molecules.
Gaussian line shapes and the absence of hyperfine (HF) pattern suggest that the
anisotropic HF interactions with the surface protons of SiO2 and TiO2 and magnetic
dipole-dipole interaction between the primary Bz-radicals occur.
The narrowing of the line width of the signal at 300K in comparison with that at 77K
(Fig. 3 and Table) confirms our suggestion about anisotropic HF interaction; as upon
increasing the temperature the interaction of Bz-radical with the surface becomes more weak
and anisotropic part of HF interaction is averaged, so ESR line is narrowed. Broadening of the
signal of the type 2 Bz-center comparing to the type 1 can be explained also by dipole-dipole
interaction between Bz-radicals of the type 2.
Now anisotropic signal of Mo5+-species are to be considered. It is beyond doubt that the
oxidation state of molybdenum is Mo5+, so we will focus attention to local structure of
Mo5+-species. For discrimination of two most common site symmetry of Mo5+-species
distorted octahedral (Oh) and tetrahedral (Td) should be regarded the following features of the
ESR signal:
i) the temperature dependence of the line shape;
ii) relative magnitudes of g^, g// and Dg-degree of g-value anisotropy.
Fig. 4. Experimental and computer simulated spectra of Mo5+ species:
1 – Mo-SiO2, 2 – Mo-TiO2 samples.
Solid line – experimental spectra; dotted line - simulated ones.
3400 3500 3600
m agnetic fie ld , G
1
2
120
Table. Parameters of paramagnetic centres of Mo-SiO2 and Mo-TiO2 samples.
Centre
type
Sample Temperature of measurement Relative
concentration*
300K 77K 300K 77K
g-value DH(mT) g-value DH(mT)
1 Mo/SiO2
Mo/TiO2
2.0023
2.0023
0.59
0.76
2.0023
2.0022
1.04
0.90
2.0
2.0
2 Mo/SiO2
Mo/TiO2
2.0019
2.0003
1.18
1.74
2.0030
1.9883
1.42
2.19
2.5
3 Mo/SiO2 - - 2.0021
3.1 3.0
4
Mo/SiO2
- - g ^ 1.946
g // 1.885
2.5
4.0
95
250
5 - - g ^ 1.946
g // 1.905
2.5
4.5
6 - - 1.95 15
7
Mo/TiO2
- - g ^ 1.944
g // 1.867
3.0
4.0
470
1600
8 - - g ^ 1.944
g // 1.900
3.0
4.0
6 - - 1.95 15
· For correct comparison of relative concentrations for Mo5+ species measured at 300 and
77K relative concentrations for Mo5+ species measured at 300 K should be multiplied by
300/77 factor.
Registration of the Mo5+ signal at 300K with the same line shape as at 77K clearly
points on distorted Oh coordination in our case. Besides, the intensities of Mo5+ species signals
recorded at 300 and 77K obeyed the Curie law. The relative concentration of Mo5+ species
(measured by double integration of spectra) revealed good coincidence between concentration
of Mo5+ species at 300 and 77K (Table). This is an important fact that confirms the absence of
Mo5+ species non-observable at room temperature but detectable at 77K. It is well known that
just tetrahedrally coordinated Mo5+ complexes can be detected only at 77K or lower because of
fast spin-lattice relaxation [13]. The absence of Td Mo5+ species has been shown for both
Mo-SiO2 and Mo-TiO2 as for impregnated and grafted samples as well.
In order to obtain the additional information about the site symmetry of Mo5+ species
a computer simulation of the line shape was performed..The results are demonstrated in the
Fig. 4 and Table. In the Fig. 4 the experimental spectra are compared Mo5+ species with
adsorbed Bz on SiO2 (spectrum 1) and on TiO2 (spectrum 2) with the simulated ones.
For Mo-SiO2 sample, a good fitting was achieved by superposition of two signals with
the following parameters: 1A g^ = 1.946; g// = 1.885; 1B g^ =1.946; g// = 1.905. Centers 1A
and 1B are denoted in the Table as centers 4 and 5. The contribution of 1B signal is three times
larger than that for 1A.
121
Similarly, for Mo-TiO2 sample, to fit satisfactorily the experimental spectrum, two
signals are also requested with such parameters: 2A g^ = 1.944; g// = 1.867; 2B g^ =1.944;
g//=1.900; centers 2A and 2B are denoted in the Table as center 7 and 8. In this case the
contributions of 2A and 2B signals into simulated spectrum are equal. It should be noted that
the fitting for Mo-SiO2 is better than that for Mo-TiO2 sample, in particular, in the g// range. It
is probable, that on TiO2 there are more than two types of Mo5+ species with the same g^ but
with slightly different g//.
The parameters obtained by computer simulation permit to discuss in more details the
local structures of Mo5+ species, taking into account relative magnitude of g^ and g// and degree
of Dg anisotropy.
All four types of revealed Mo5+ centers are characterized by g^>g//, that gives clear
evidence on the presence of octahedral distorted (compressed) Mo5+oxo-complexes with
Mo=O double bond [18]. The elongated octahedral complexes exhibit reversal relation
g^<g// [13]. Distorted tetrahedral Mo5+ complexes are characterized by essentially different
g-values and significantly greater Dg. Besides it has been shown that tetrahedral Mo5+ species
are generated only by low temperature (77K) photoreduction and are irreversibly transformed
into octahedral at room temperature [8].
Revealed two types of octahedral Mo5+ species, as it seen in the Table, display different
degree of Dg anisotropy; in accordance with [8] it reflects the different degree of symmetry
distortion. Tentatively we presume, that it may be connected with two different routes of
reducing of supported Mo: the former is achieved during thermoevacuation and is caused by
O2- extraction, while the second - by electron donating from Bz molecule. In the first case
more distorted penta-coordinated Mo5+ species will be formed (centers 4 and 7), while the
electron donating will result in less distorted six-coordinated Mo5+ species generation
(centers 5 and 8).
Besides above-described types of Mo5+ species, it was revealed also the presence of
additional type (on both Mo-SiO2 and Mo-TiO2 samples). Computer simulation of
experimental spectra 1b (Fig. 1) and 2b (Fig. 2) using the parameter for centers 1-3; 4-5
and 7-8 in the Table revealed the presence of additional center 6 with isotropic g-value g=1.95
and very large linewidth (DH=15 mT). Fig. 5 demonstrates the presence of Mo5+ centers of
type 6 (1b curve - for Mo-SiO2; 2b curve - for Mo-TiO2). The contribution of type 6 center to
total Mo5+ spectrum is 1/5 for Mo-SiO2 and 1/3 for Mo-TiO2. Obtained g-value of this center
is in a good agreement for polymolybdate clusters like molybdenum “blues” or
heteropolyanions, reported in the literature [19-20]. But a certain controversy should be noted
concerning the line width and its temperature dependence. At present time we have no
sufficient data to discuss this question.
An analysis of data concerning the total concentration of Bz radicals (centres 1-3) and
Mo5+-species (centres 4-6) for Mo-SiO2 sample revealed an important fact. It appeared, that
the concentration of Bz radicals is more than 40 times less comparing to the total Mo5+species
concentration. For this sample Mo5+-species are formed mainly during the redox process that
can be schematically written as
Benzene+ Mo6+à Bz-radical + Mo5+ species (1)
122
Fig. 5. Integrated form of experimental spectra: 1 - Mo-SiO2 , 2 - Mo-TiO2 samples.
Curve 1a is integrated form of experimental spectrum 1b (from Fig. 1);
curve 2a is integrated form of experimental spectrum 2b (from Fig. 2);
curves 1b and 2b are simulated ones for Mo5+ species (6 type centers in the Table).
This oversimplified schematic representation (1) predicts that the concentration of
Bz-radicals and Mo5+-species should be equal. So, observed discrepancy in these
concentrations indicates that the significant part of Bz radicals is ESR-silent. We consider this
fact as an independent confirmation of complicated secondary reactions of primary Bz-radicals
already discussed in this paper.
Conclusions
Direct experimental ESR evidence was obtained that the benzene chemisorption on the
surface species of supported molybdenum results in one-electron redox processes and
paramagnetic centres formation - reduced molybdenum (Mo+5 -species) and benzene radicals
(Bz-radicals). Computer treatment of ESR experimental data revealed the superposition of
several types of Mo+5-species and Bz-radicals. There are three types of Bz-radicals on
Mo-SiO2 and two types on Mo-TiO2 samples. All Bz-radicals showed singlet with Gauss line
shape signals with slight difference in g-values and noticeable one in linewidths. Such features
of Bz-radicals spectra are explained as a result of secondary transformations and
rearrangements of the primary Bz-cation radicals that led to polyphenyl radical formation.
Besides, the anisotropic hyperfine coupling of primary Bz-radicals and their dipole-dipole
interactions are also considered to be responsible for unresolved singlet lineshape.
The are three types of Mo5+-species on both Mo-SiO2 and Mo-TiO2 samples. Two of
Mo5+-species displayed the features, typical for localized Mo5+state with distorted octahedral
coordination. The analysis of g-value magnitudes and degree of Dg anisotropy give evidence
320 340 360 380
2b
2a
1b
1a
magnetic field, mT
123
for penta-coordinated and six-coordinated distorted octahedral Mo5+-species. The assumption
is advanced that different degree of octahedral Mo5+-species distortion reflects two different
routes of reduced Mo5+-species formation: extraction of O2- at thermoevacuation and electron
donating at benzene interaction. Third type of Mo5+species exhibited the characteristics of
Mo5+ clusters.
References
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Abstract
Abstract
Abstract
Abstract
Abstract
Introduction
Experimental
Experimental
Sample preparation and trearment. Molybdenum-containing samples were prepared using two methods:
ESR measurement. Spectra were recorded at 300 and 77K with SEX-2543 spectrometer (Radiopan). Experimental g-values were determined by direct measurements of the frequency and magnetic field. For computer simulation of ESR spectra the programs WINEPR and SIMFONIA (Bruker) were used.
Results and discussion
Temperature of measurement
Conclusions
Conclusions
Conclusions
Conclusions
References
|
| id | oai:ojs.pkp.sfu.ca:article-89 |
| institution | Surface |
| keywords_txt_mv | keywords |
| language | English |
| last_indexed | 2025-07-22T19:30:10Z |
| publishDate | 2002 |
| publisher | Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine |
| record_format | ojs |
| resource_txt_mv | surfacezbircomua/41/32e31e121b32560e82a3278368c31041.pdf |
| spelling | oai:ojs.pkp.sfu.ca:article-892018-11-27T09:42:19Z Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene Ignatovych, M. Teslenko, V. Eremenko, A. Ogenko, V. Chuiko, A. The study is devoted to ESR-investigation of the primary processes upon chemisorption of benzene molecules onto the molybdenum supported on dispersed SiO2 and TiO2 samples. It has been confirmed that benzene chemisorption onto the Mo6+ species results in one-electron transfer in the ground state and paramagnetic species formation, namely reduced molybdenum species (Mo5+ species) and radicals of benzene. Computer treatment of ESR experimental data revealed that there are several types of Mo5+ species and benzene radicals, the assignment of which is proposed. The study is devoted to ESR-investigation of the primary processes upon chemisorption of benzene molecules onto the molybdenum supported on dispersed SiO2 and TiO2 samples. It has been confirmed that benzene chemisorption onto the Mo6+ species results in one-electron transfer in the ground state and paramagnetic species formation, namely reduced molybdenum species (Mo5+ species) and radicals of benzene. Computer treatment of ESR experimental data revealed that there are several types of Mo5+ species and benzene radicals, the assignment of which is proposed. The study is devoted to ESR-investigation of the primary processes upon chemisorption of benzene molecules onto the molybdenum supported on dispersed SiO2 and TiO2 samples. It has been confirmed that benzene chemisorption onto the Mo6+ species results in one-electron transfer in the ground state and paramagnetic species formation, namely reduced molybdenum species (Mo5+ species) and radicals of benzene. Computer treatment of ESR experimental data revealed that there are several types of Mo5+ species and benzene radicals, the assignment of which is proposed. Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2002-06-12 Article Article application/pdf https://surfacezbir.com.ua/index.php/surface/article/view/89 Surface; No. 7-8 (2002): Chemistry, Physics and Technology of Surface; 115-124 Поверхность; № 7-8 (2002): Химия, физика и технология поверхности; 115-124 Поверхня; № 7-8 (2002): Хімія, фізика та технологія поверхні; 115-124 3154-8091 3154-8083 en https://surfacezbir.com.ua/index.php/surface/article/view/89/88 Авторське право (c) 2002 M. Ignatovych, V. Teslenko, A. Eremenko, V. Ogenko, A. Chuiko |
| spellingShingle | Ignatovych, M. Teslenko, V. Eremenko, A. Ogenko, V. Chuiko, A. Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene |
| title | Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene |
| title_alt | Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene |
| title_full | Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene |
| title_fullStr | Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene |
| title_full_unstemmed | Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene |
| title_short | Electron spin resonance study on Mo SiO2 and Mo TiO2 with adsorbed benzene |
| title_sort | electron spin resonance study on mo sio2 and mo tio2 with adsorbed benzene |
| url | https://surfacezbir.com.ua/index.php/surface/article/view/89 |
| work_keys_str_mv | AT ignatovychm electronspinresonancestudyonmosio2andmotio2withadsorbedbenzene AT teslenkov electronspinresonancestudyonmosio2andmotio2withadsorbedbenzene AT eremenkoa electronspinresonancestudyonmosio2andmotio2withadsorbedbenzene AT ogenkov electronspinresonancestudyonmosio2andmotio2withadsorbedbenzene AT chuikoa electronspinresonancestudyonmosio2andmotio2withadsorbedbenzene |