Synthesis and Hydrogen Desorption Properties of Nanoscale α-AlH3

Article abstract of DOI:10.1134/S0036024419130417

Abstract: Aluminum hydride is particularly attractive as a hydrogen storage material due to its high hydrogen volumetric capacity and relatively low hydrogen desorption temperature. However, the properties of nanoscale α?AlH₃ particles are not studied completely due to the difficulties in their synthesis. In this work, we report the synthesis of nanoscale α-AlH₃ based on a modified method, together with its activation energy measurements and hydrogen release kinetics. We have discovered that the dehydrogenation activation energy (93.23 kJ/mol) of nanoscale α-AlH₃ is remarkably lower than that of micrometer-sized α-AlH₃, which further expand practical application of AlH₃. Moreover, we demonstrate that the decomposition kinetics of nanoscale α-AlH₃ is controlled by nucleation and growth of the aluminum phase in three dimensions. This work first time provides systematic investigation of thermodynamic properties of nano-scale AlH₃, which paves the way for its practical applications.

Full text of DOI:10.1134/S0036024419130417

ISSN 0036-0244, Russian Journal of Physical Chemistry A, 2019, Vol. 93, No. 13, pp. 2798–2803. © Pleiades Publishing, Ltd., 2019.
PHYSICAL CHEMISTRY OF NANOCLUSTERS
AND NANOMATERIALS
Synthesis and Hydrogen Desorption Properties of Nanoscale α-AlH3
Zhaoyang Zhua,b,c, Debin Xiaa, Yuling Lia, Ping Wanga, Kaifeng Lina, Jizhuang Fand,*,
Ruiqing Fana, and Yulin Yanga,**
aMIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry
and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001 P. R. China
bScience and Technology on Aerospace Chemical Power Laboratory, Xiangyang, 441003 P. R. China
cHubei Institute of Aerospace Chemotechnology, Xiangyang, 441003 P. R. China
dState Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150080 P. R. China
* e-mail: fanjizhuang@hit.edu.cn
**e-mail: ylyang@hit.edu.cn
Received January 13, 2019; revised January 13, 2019; accepted February 12, 2019
Abstract—Aluminum hydride is particularly attractive as a hydrogen storage material due to its high hydrogen
volumetric capacity and relatively low hydrogen desorption temperature. However, the properties of
nanoscale α-AlH3 particles are not studied completely due to the difficulties in their synthesis. In this work,
we report the synthesis of nanoscale α-AlH3 based on a modified method, together with its activation energy
measurements and hydrogen release kinetics. We have discovered that the dehydrogenation activation energy
(93.23 kJ/mol) of nanoscale α-AlH3 is remarkably lower than that of micrometer-sized α-AlH3, which fur-
ther expand practical application of AlH3. Moreover, we demonstrate that the decomposition kinetics of
nanoscale α-AlH3 is controlled by nucleation and growth of the aluminum phase in three dimensions. This
work first time provides systematic investigation of thermodynamic properties of nano-scale AlH3, which
paves the way for its practical applications.
Keywords: aluminum hydride, metal hydride, hydrogen storage, hydrogen desorption
DOI: 10.1134/S0036024419130417
INTRODUCTION
of dehydrogenation kinetics of AlH3 is crucial for
improving the hydrogen desorption performance.
Alternative energy sources have received great
attention due to the exhaustion of fossil fuel and severe
environmental pollution [1]. Among them, hydrogen
energy is widely considered as a feasible secondary
energy for future owing to its abundant reserves, high
In recent years, the synthesis and dehydrogenation
thermodynamics and kinetics of AlH3 are reported.
Herley et al. [17] measured the activation energy for
the acceleratory and decay period for α-AlH3 with
large particles (50–100 μm) manufactured by DOW
calorific value, nontoxicity, and various forms of utili- Chemical to be approximately 157 kJ/mol. Gabis et al.
[18] reported the activation energy of a larger crystal-
lites (10–20 μm) of α-AlH3 to be 104 kJ/mol. Graetz
et al. [19] investigated the thermal decomposition of
α-, β-, and γ-AlH3 prepared via the micro-crystalliza-
tion route, consisting of small particles of 100–
200 nm. It is a fact that the present investigation is lim-
ited to the sub-micrometer and micrometer sized
α-AlH3. Until 2016, Wanseop Jeong et al. [11, 20] syn-
thesized nanoscale α-AlH3 with diameter of approxi-
mately 50 nm by using an electrochemical method
proposed by Graetz et al. [21] and Dow Chemical Co.
[5]. However, it must be mentioned that this investiga-
tion did not involved the research of dehydrogenation
kinetics of α-AlH3.
zation [2–6]. However, since it is flammable and
explosive, hydrogen storage is still a bottleneck tech-
nique [3, 6–8]. Metal hydrides are generally superior
to pressurized gas and other hydrogen storage methods
because of their high mass and volume storage density
and safe operating pressure [1]. Aluminum hydride,
which has the largest hydrogen volumetric capacity
(4.9 kW h/L) among metal hydrides and, moreover,
low desorption temperature (100–200°C), is widely
acknowledged as a fascinating hydrogen storage mate-
rial [3, 4, 8–16], especially for hydrogen fuel cells.
However, the high-activation barrier and the overall
slow desorption kinetics measured for large cuboid
AlH3 hamper its practical application in the fuel-cell
In this study, nanoscale α-AlH3 was prepared via a
vehicles [11]. Developing a systematic understanding modified ethereal reaction method. By isothermal
2798

SYNTHESIS AND HYDROGEN DESORPTION PROPERTIES
2799
(a) Detection section
Digital pressure gauge
(b) Reaction section
Vacuum-pumping
Reservoir chamber
Oil-bath pan 1
Sample chamber
Oil-bath pan 2
Fig. 1. (Color online) Schematic diagram of the self-made isothermal hydrogen desorption reaction apparatus.
decomposition of as-prepared nanoscale α-AlH3, its
dehydrogenation kinetics systematically investigated
for the first time. The activation energy and kinetic
parameters of nanoscale α-AlH3 dehydrogenation
were estimated through Avrami–Erofeyev and Arrhe-
nius equations. It has been verified that nanoscale
α-AlH3 have a smaller activation energy and a faster
hydrogen evolution rate.
Dehydriding of As-prepared α-AlH3
The hydrogen desorption measurements were car-
ried out on a self-made apparatus with a high-preci-
sion digital pressure gauge (Fig. 1). This apparatus
contains the detection section and the reaction section
connected through a rubber pipe. The internal vol-
umes of these two sections are calibrated prior to mea-
surements with the volume of 265 mL. The relation-
ship between the pressure and the gas volume of the
reservoir chamber under the given temperature, as well
as the relationship between the real temperature inside
the experimental device and the set temperature were
also calibrated. There are two oil-baths in the detec-
tion section and the reaction section. One is employed
to ensure that the temperature of the reservoir cham-
ber is stable, considering the influence of the ambient
temperature, while the other is used to keep the
decomposition temperature. In the hydrogen desorp-
tion measurements, the sample chamber filled with
as-prepared nanoscale α-AlH3 is put in the oil-bath
when the given desorption temperature become stable.
Therefore this self-made apparatus could prevent the
decomposition of the samples during it is heated to the
ideal desorption temperature which occurs in many
isothermal decomposition experiments. The sample
chamber is relatively small, thus the fluctuation of its
temperature could be ignored. During measurements,
the temperature and pressure data were collected
during fixed intervals of time. Hence, the amounts of
hydrogen were calculated by the ideal gas equation
using the obtained temperature and pressure data of
the reservoir chamber. On carrying isothermal dehy-
drogenation experiments, 100 mg sample was loaded
into the evacuated sample chamber and kept at a given
temperature (130, 140, 150, 160, and 170°C) till the
completion of dehydriding.
EXPERIMENTAL
Synthesis of Nanoscale α-AlH3
α-AlH3 was typically synthesized using the modi-
fied ethereal reaction method developed by Brower
et al. [5, 22]. The ether solution of LiAlH4 (2 mol/L)
and AlCl3 (1 mol/L) were both prepared at –10°C.
Then these solutions were mixed at –10°C to produce
an etherated aluminum hydride, AlH3 · n(Et2O):
4LiAlH4 + AlCl3 + nEt2O
(I)
→ 4AlH3 ⋅ nEt2O + 3LiCl↓ + LiAlH4.
At the end of the reaction, the precipitated lithium
chloride was filtered by using a sand core funnel, and
then the white AlH3 · n[(C2H5)2O] precipitated in 1 h
while stirring at room temperature. After being filtered
off and placed in a vacuum oven at 45°C for 2 h, we
obtained the dry etherated aluminum hydride. By
heating this product at 65–75°C under vacuum for 5 h,
the associated ether was removed successfully:
65−75°C
(II)
4AlH3 ⋅ nEt2O ⎯⎯⎯→ 4AlH3 + nEt2O↑.
5h
Finally, the product was washed with ether to
remove the excess LiAlH4. It must be mentioned that
all sample handling was performed under inert gas.
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A Vol. 93 No. 13 2019

2800
ZHAOYANG ZHU et al.
(a)
As-prepared α-AlH3
α-AlH3
20
40
60
2θ, deg
80
(c)
TGA
2
98
94
90
DSC
0
163°C
−2
5 μm
(b)
100
200
T, °C
300
Fig. 2. (Color online) (a) X-ray diffraction patterns, (b) SEM images, (c) TGA-DSC curves of as-prepared α-AlH powder.
3
Characterization of As-prepared α-AlH3
49.5°, 56.8°, 62.78°, 65.74°, and 67.7°, corresponding
to (012), (104), (110), (006), (113), (202), (024), (116),
and (122) planes of α-AlH3 (JCPDF 23-0761),
respectively. The diffraction peaks were sharp and
intense, indicating its highly crystalline nature. No
other peaks were observed, indicating the purity of the
product.
Powder X-ray diffraction (XRD) measurements
were conducted on a PANalytical X-ray diffractome-
ter (X’Pert Pro) using CuKα radiation. The XRD data
were analyzed by means of MDI Jade 6 software.
Scanning electron microscopy (SEM, FEI SIRION
100 or Hitachi S4800) was utilized to study the mor-
phology of the sample. With regard to the hydrogen
capacity, elemental analyses were implemented utiliz-
As can be seen from Fig. 2b, the SEM micrograph
of as-prepared α-AlH3 exhibits small crystallites
ing a Leco CHNS-932 Micro-analyzer. The Fourier which is different from a typical topographic charac-
transform infrared spectroscopy (FT-IR, Nicolet teristics of cubic α-AlH3. This phenomenon may arise
iS50) was performed in a wavenumber range from 400
to 4000 cm–1 using the samples prepared by KBr pel-
leting method. Synchronous thermal analyses were
carried out with a thermo-gravimetric analysis and
differential scanning calorimetry (TGA-DSC, Met-
tler-Toledo TGA/SDTA851e). The samples were
heated from room temperature to about 300°C with a
heating rate of 10oC/min under N2 atmosphere.
from the conglomeration of nanometer α-AlH3 parti-
cles for its high surface energy. The average grain size
of the as-prepared α-AlH3 is estimated to be approxi-
mately 60 nm according to Scherrer’s equation [23]:
Kλ
B cos θ
(1)
D =
,
where D is the average grain size, λ is the wavelength of
the incident X-ray, B is the full width at half-maxi-
mum of a diffraction peak, θ is the Bragg angle, and K
is a constant depending on the shape of the grains
(generally assumed to be 0.89).
RESULTS AND DISCUSSION
Structure of As-prepared α-AlH3
The diffraction pattern of the as-prepared α-AlH3
In order to further verify the crystal form of AlH3
(Fig. 2a) has seven peaks at 27.5°, 38.2°, 40.3°, 45.9°, and gain an insight into the hydrogen capacity of it,
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A
Vol. 93
No. 13
2019

SYNTHESIS AND HYDROGEN DESORPTION PROPERTIES
2801
ꢀ-AlH3
0 min
(a)
(b)
Al
After the dehydrogenation
2.5 min
3.5 min
As-prepared ꢀ-AlH3
5 min
1850
876
40 min
1722
673
20
40
60
80
4000
3000
2000
ꢂ, cmꢃ1
1000
2ꢁ, deg
Fig. 3. (Color online) (a) XRD patterns of as-prepared α-AlH heated for different time intervals; (b) infrared spectra of as-pre-
3
pared α-AlH before and after dehydrogenation at 160°C.
3
TGA-DSC measurement was carried out. As shown in sented in Fig. 3b. It shows absorption bands in 1850,
1722, 876, and 673 cm–1 regions indicating the pres-
Fig. 2c, the DSC curve of the as-prepared α-AlH3
exhibits a one-step endothermic desorption process ence of Al‒H bond before desorption. After desorp-
starting at 150°C and peaking at 163°C, which is in tion the curve approaching a straight line, which tes-
accordance with literature data. The endothermic tify that after being heated for 40 min, the α-AlH3 has
reaction is attributed to the dehydriding of the as-pre-
pared α-AlH3. From the TGA curve Fig. 2c, it can be
found that the weight loss rate of as-prepared α-AlH3
is approximately 7.8 wt %. The result of elemental (H)
analysis shows the average hydrogen capacity of pre-
pared α-AlH3 is 7.59 wt %, which is in accordance
with the result of TGA-DSC analysis (Fig. 2d). This
low hydrogen content value might arise from the slight
decomposition during preparation, which has no
influence on the hydrogen desorption experiment.
been completely transform into Al. This is consistent
with the observation from XRD.
The activation energy and pre-exponential factor
for α-AlH3 isothermal dehydrogenation can be deter-
mined using Avrami–Erofeyev and Arrhenius equa-
tions [11, 24]. The direct hydrogenation of Al to form
AlH3 can be considered irreversible as it requires
extremely high hydrogen pressure (over 105 bars) at
room temperature [12, 13, 15]:
105 bar, 25°C
(III)
Al + 3/2H2 ⎯⎯⎯⎯→ AlH3.
Dehydriding Properties of As-prepared α-AlH3
Irreversible isothermal solid-state reactions can
generally be expressed by Avrami–Erofeyev equation
[3, 25, 26]:
The hydrogen release from α-AlH3 follows the sim-
ple reaction (AlH3 → Al + 3/2H2) [24]. In order to
trace the isothermal dehydrogenation of nanometer
α-AlH3, XRD measurements were carried out. The
XRD patterns of as-prepared α-AlH3 heated for dif-
ferent time intervals at 160°C is illustrated in Fig. 3a.
The five selected time points correspond to the hydro-
gen desorption fraction of 0, 25, 50, 75, and 100%,
respectively in accordance with the isothermal dehy-
drogenation curves. As shown in Fig. 3a, the desorp-
tion time of α-AlH3 significantly affects the phase
composition. After heating for 2.5 min at 160°C, five
small peaks appeared, indicating the formation of Al,
arising from the decomposition of α-AlH3. With fur-
ther increase in the heating time, the peaks corre-
sponding to Al phase significantly enhanced while the
α-AlH3 phase remarkably weaken. After heating for
40 min, α-AlH3 completely decomposed to a pure Al
phase. The IR spectrum of the as-prepared α-AlH3
before and after dehydrogenation at 160°C is pre-
1/n
(2)
[–ln(1 − α)] = kt,
where α is the fraction of material reacted in one inter-
val (t). The constant n depends on the geometry of
particle growth. In accordance with the slope of a plot
of ln[–ln(1 – α)] versus lnt, the rate-limiting mecha-
nism and the appropriate kinetic equation can be
determined [22]. In the nucleation and growth model,
n is a function of the nucleation barrier and growth
geometry. The value of n ≈ 1, 2, 3 indicates the linear
growth, two-dimensional growth (disk or cylinder
growth), and three-dimensional growth (spheres or
hemispheres growth) [25, 27]. The Arrhenius equation
demonstrates the relationship between the reaction
rate k(T), activation energy, and the temperature:
Ea
RT 




(3)
k(T ) = A exp –
,

RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A Vol. 93 No. 13 2019

2802
ZHAOYANG ZHU et al.
(a)
(b)
0
1.0
0.8
0.6
0.4
0.2
0
130ꢄC
140ꢄC
150ꢄC
160ꢄC
170ꢄC
ꢃ1
ꢃ2
0
1
2
3
4 (ꢅ103)
4
5
6
lnt
7
8
Time, s
1.4
1.2
1.0
0.8
0.6
0.4
(c)
(d)
ꢃ5
ꢃ6
ꢃ7
0
4
8
12
16 (ꢅ102)
ꢃ2.5
ꢃ2.4
ꢃ1/T, Kꢃ1
ꢃ2.3 (ꢅ10ꢃ3)
Time, s
Fig. 4. (Color online) Decomposition of as-prepared nanoscale α-AlH between 130 and 170°C plotted as (a) fractional decom-
3
1/3
position, α, vs. t; (b) ln[–ln(1 – α)] vs. ln t; and (c) ln[–ln(1 – α)] vs. t; (d) Arrhenius plot.
where A is the pre-exponential Arrhenius parameter, sub-micron particle which average value of n were
Ea is the activation energy, and R is the universal gas closer to 2 [11, 16]. This value indicates that the growth
constant.
The activation energy and pre-exponential param-
of the Al phase of nanoscale α-AlH3 more likely to
occurs three-dimensions rather than two-dimensions
[11].
eters are determined by the slope and intercept of the
Arrhenius plot, respectively. The isothermal ( 1°C)
fractional decomposition data for α-AlH3 are shown
in Fig. 4a. All these curves show sigmoidal features
with induction, acceleration, and decay periods. Fig-
ure 4b shows the plot of ln[–ln(1 – α)] as the function
of the lnt, and is used to measure the constant, n in
acceleration periods, and determine the most suitable
kinetic equation. The values of n obtained from Fig. 4b
are listed in Table 1. As shown in Table 1, the average
value of n was approximately 3, suggesting that
The fraction of decomposed α-AlH3 plotted as
[‒ln(1 – α)]1/3 is shown in Fig. 4c. The rate constants
determined from the slope are displayed in Table 1.
Arrhenius plots for α-AlH3 over a temperature range
of 130 to 170°C are displayed in Fig. 4d. Kinetic values
for the as-prepared α-AlH3 are equal: particle diame-
ter d = 60 nm, Ea = 93.23 0.81 kJ/mol, A = 7.49 ×
108 2.22.
This two kinetic parameters are both lower than the
nanoscale α-AlH3 follows third-order Avrami–Erofe- values measured by Herley et al. [16] (A = 3.5 × 1016
yev equation which is different from the micron and
and Ea = 150.3 10.0 kJ/mol) and Graetz et al. [11]
Table 1. The values of n obtained from Fig. 4b and isothermal decomposition rate constants (s–1) for as-prepared α-AlH3
T, °C
130
140
150
160
170
n
3.06
3.18
2.75
2.733
3.29
3.00 (average)
k, s–1
5.89 × 10–4
1.32 × 10–3
2.23 × 10–3
4.19 × 10–3
7.63 × 10–3
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A
Vol. 93
No. 13
2019

SYNTHESIS AND HYDROGEN DESORPTION PROPERTIES
2803
(A = 1.2 × 1010 and Ea = 102.2 3.2 kJ/mol) consid-
erably. It is worthwhile mentioning that the particle
diameter of as-prepared α-AlH3 is around 60 nm,
while that of α-AlH3 prepared by Herley et al. and
Graetz et al. are 100 μm and 204 nm, respectively.
Thus, it can be concluded that the significantly
decreasing of the pre-exponential factor and activa-
tion energy for α-AlH3 is attributed to the smaller par-
ticle size. As the grain size of α-AlH3 decreases, the
specific surface area become larger so that its molar
surface energy increases. That improves the average
molar energy of the α-AlH3, thereby reducing the gap
(activation energy) between the average energy of
1 mol activated molecules and 1 mol reactants.
4. H. Liu, X. Wang, Z. Dong, G. Cao, Y. Liu, L. Chen,
and M. Yan, Int. J. Hydrogen Energy 38, 10851 (2013).
5. F. M. Brower, N. E. Matzek, P. F. Reigler, H. W. Rinn,
C. B. Roberts, D. L. Schmidt, J. A. Snover, and
K. Terada, J. Am. Chem. Soc. 98, 2450 (1976).
6. T. Roubicek and G. Tomassetti, Discrete Cont. Dyn.
Syst., Ser. B 19, 2313 (2017).
7. H. Liu, X. Wang, H. Zhou, S. Gao, H. Ge, S. Li, and
M. Yan, Int. J. Hydrogen Energy 41, 22118 (2016).
8. R. Chen, C. L. Duan, X. Liu, K. Qu, G. Tang, X. X. Xu,
and B. Shan, J. Vacuum Sci. Technol. A 35, 03E111
(2017).
9. J. Graetz, Chem. Soc. Rev. 38, 73 (2009).
10. S. Gao, H. Liu, X. Wang, L. Xu, S. Liu, P. Sheng,
G. Zhao, B. Wang, H. Li, and M. Yan, Int. J. Hydrogen
Energy 42, 25310 (2017).
CONCLUSION
11. J. Graetz and J. J. Reilly, J. Phys. Chem. B 109, 22181
(2005).
Single-phase nanoscale α-AlH3 was synthesized by
modified ethereal reaction method. According to
Avrami–Erofeyev equation, the decomposition kinet-
ics of nanoscale α-AlH3 are controlled by nucleation
and growth of the aluminum phase in three rather than
two dimensions, different from micro and sub-micro
α-AlH3. The activation energy and pre-exponential
factor of dehydriding of as-prepared nanoscale
α-AlH3 was estimated to be 93.23 kJ/mol and 7.49 ×
12. R. Zidan, B. L. Garcia- Diaz, C. S. Fewox, A. C. Stowe,
J. R. Gray, and A. G. Harter, Chem. Commun., 3717
(2009).
13. S. Kato, M. Bielmann, K. Ikeda, S. Orimo, A. Borg-
schulte, and A. Züttel, Appl. Phys. Lett. 96, 687 (2010).
14. J. Graetz and J. J. Reilly, J. Alloys Compd. 424, 262
(2006).
15. Y. Nakagawa, S. Isobe, Y. Wang, N. Hashimoto,
S. Ohnuki, L. Zeng, S. Liu, T. Ichikawa, and Y. Koji-
ma, J. Alloys Compd. 580, S163 (2013).
108, respectively. The activation energy is significantly
lower than that for the micron and sub-micron size
α-AlH3. The activation energy of nanoscale α-AlH3
decomposition is significantly reduced as a result of
smaller grain diameter. Thus, the synthesis of α-AlH3
with smaller particle size may be an effective way to
solve the difficulties in application of AlH3.
16. P. J. Herley and O. Christofferson, J. Phys. Chem. 85,
1874 (1981).
17. T. T. Ma and R. X. Gu, Power Technol. 31, 95 (2014).
18. I. Gabis, M. Dobrotvorskiy, E. Evard, and A. Voyt,
J. Alloys Compd. 509, S671 (2011).
19. J. Graetz and J. J. Reilly, J. Phys. Chem. B 109, 22181
(2005).
ACKNOWLEDGMENTS
20. W. Jeong, S. H. Lee, and J. Kim, J. Nanosci. Nano-
technol. 16, 2987 (2016).
This work was supported by the National Key R&D
Program of China (grant no. 2017YFB1300104), National
Natural Science Foundation of China (grant no. 21571042,
21371040), Science Foundation of Aerospace (grant
nos. 6141B0626020201, 6141B0626020101) and the Post-
doctoral Foundation of Heilongjiang Province (grant
no. LBH-Z16059).
21. J. G. And and J. J. Reilly, J. Phys. Chem. B 109, 22181
(2005).
22. T. B. Tang and M. M. Chaudhri, J. Therm. Anal. 18,
247 (1980).
23. H. Borchert, E. V. Shevchenko, A. Robert, I. Mekis,
A. Kornowski, G. Grübel, and H. Weller, Langmuir
21, 1931 (2005).
24. Y. Wang, J. A. Yan, and M. Y. Chou, Phys. Rev. B 77
REFERENCES
(1) (2008).
25. J. H. Sharp, G. W. Brindley, and B. N. N. Achar,
1. C. W. Duan, L. X. Hu, and J. L. Ma, J. Mater. Chem.
J. Am. Ceram. Soc. 49, 379 (1966).
A 6, 6309 (2018).
26. M. Zhou, Q. L. Xu, P. Lan, W. Yuan, X. Y. Sun,
S. Z. Xin, and Y. J. Yan, J. Jilin Inst. Chem. Technol.
26, 35 (2009).
2. H. Liu, X. Wang, Y. Liu, Z. Dong, S. Li, H. Ge, and
M. Yan, J. Phys. Chem. C 118, 18908 (2014).
3. H. Liu, X. Wang, Y. Liu, Z. Dong, H. Ge, S. Li, and
27. C. P. Constantinou, Int. J. Chem. Kinet. 26, 1151
M. Yan, J. Phys. Chem. C 118, 37 (2013).
(1994).
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A Vol. 93 No. 13 2019