Preparation of NdCrO3 nanoparticles and their catalytic activity in the thermal decomposition of ammonium perchlorate by DSC/TG-MS

Article abstract of DOI:10.1007/s10973-009-0091-7

Orthorhombic structural perovskite NdCrO₃ nanocrystals with size of 60 nm were prepared by microemulsion method, and characterized by XRD, TEM, HRTEM, SEM, EDS and BET. The catalytic effect of the NdCrO₃ for thermal decomposition of

Full text of DOI:10.1007/s10973-009-0091-7

J Therm Anal Calorim (2009) 97:903–909
DOI 10.1007/s10973-009-0091-7
Preparation of NdCrO nanoparticles and their catalytic activity
3
in the thermal decomposition of ammonium perchlorate
by DSC/TG-MS
Zongxue Yu Æ Yuxi Sun Æ Wenxian Wei Æ
Lude Lu Æ Xin Wang
Received: 26 October 2008 / Accepted: 6 January 2009 / Published online: 19 June 2009
Ó Akad e´ miai Kiad o´ , Budapest, Hungary 2009
Abstract Orthorhombic structural perovskite NdCrO3
nanocrystals with size of 60 nm were prepared by micro-
emulsion method, and characterized by XRD, TEM,
HRTEM, SEM, EDS and BET. The catalytic effect of the
NdCrO3 for thermal decomposition of ammonium per-
chlorate (AP) was investigated by DSC and TG-MS. The
metal oxides, ABO perovskite-type oxides with A as La, B
3
as transition metal were considered strategic materials due
to their prominent electronic, magnetic, optic, catalytic
activities and application in many fields [1–4]. In ACrO3
(A = La, Y, Nd and Sm) perovskite system, many inves-
tigations have been focused on pure and doped materials of
the former two. ACrO3 has been prepared by various
techniques: a solid-state reaction [5, 6], a coprecipitation
method [7], a simultaneous crystallization method [7], a
citric gel processing [8], and a combustion synthesis [9, 10].
Ammonium perchlorate (AP) is the most common oxi-
dizer in composite solid propellants. The thermal decompo-
sition characteristics influence the combustion behavior of
the propellant [11]. The catalytic activities of some transition
metal oxides and metal powders in the thermal decomposi-
tion of AP have been reported [12–17] and improved catalytic
performance can be obtained from nanometer-scale catalysts
results revealed that the NdCrO nanoparticles had effective
3
catalysis on the thermal decomposition of AP. Adding 2%
of NdCrO nanoparticles to AP decreased the temperature
3
of thermal decomposition by 87° and increased the heat of
decomposition from 590 to 1073 J g . Gaseous products
-
1
of thermal decomposition of AP were NH , H O, O , HCl,
3
2
2
N O, NO, NO and Cl . The mechanism of catalytic action
2
2
2
-
was based on the presence of superoxide ion O2 on the
surface of NdCrO , and the difference of thermal decom-
3
position of AP with 2% of NdCrO and pure AP was mainly
3
caused by the different extent of oxidation of ammonium.
[18–20]. We previously reported the catalytic activities of the
Keywords NdCrO nanoparticles Á Ammonium
perovskite-type oxides nanoparticles for the thermal decom-
position of AP [21]. The aim of this work was to investigate
3
perchlorate Á Catalytic activity Á Thermal decomposition Á
Thermogravimetry-mass spectrometry
the catalytic activities of NdCrO nanocrystals prepared by
3
the microemulsion method on the thermal decomposition of
AP. The emphasis of the work is on the mechanism of the
process studied by DSC and TG-MS technique.
Introduction
The vast majority of catalysts used in modern chemical
industry is based on mixed metal oxides. Among the mixed
Experimental
Z. Yu Á Y. Sun Á W. Wei Á L. Lu (&) Á X. Wang
Key Laboratory of Educational Ministry for Soft Chemistry
and Functional Materials, Nanjing University of Science
and Technology, Nanjing 210094, Jiangsu, China
e-mail: haiqingy@163.com
Materials
All the reagents were analytical grade chemicals.
Cr(NO ) Á 9H O, Nd O and sodium dodecylbenzenesul-
3
3
2
2 3
fonate were obtained from the Shanghai Chemical Factory;
Z. Yu
Department of Chemical Engineering, Chongqing Three Gorges
College, Wanzhou, 404000 Chongqing, China
HNO , ethanol and toluene were produced by the Nanjing
3
chemical factory.
123

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04
Z. Yu et al.
Preparation of NdCrO nanoparticles
3
dodecylbenzenesulfonate [CH (CH ) (C H )SO ]Na (NaDBS)
3
2 11
6
4
3
as surfactant. The synthesis starts with 0.005 mol of Nd O
2
3
NdCrO nanoparticles were synthesized through the for-
3
(dissolved in 1:1 HNO ) and 0.01 mol of Cr(NO ) dis-
3 3 3
mation of water-in-toluene reverse micelles with sodium
solved in 25 mL of water to form a clear solution. A 0.4 M
NaDBS aqueous solution (25 mL) was added into the metal
salt solution and followed by the addition of a large volume
1
00
80
DTG(a,AP+2%NdCrO3)
(c)
TG(a,AP+2%NdCrO3)
6
4
2
0
0
0
9
8%
0
(b)
1
00
TG(b,pure AP)
1
5%
8
6
4
2
0
0
0
0
8
5% DTG(b,pure AP)
(a)
0
20
30
40
50
O
2Theta /
100
200
300
Temperature/ C
400
500
o
Fig. 1 XRD pattern of the NdCrO calcined at different temperature
3
for 4 h (a) 700 °C; (b)800 °C; (c) 900 °C
Fig. 4 TG and DTG curves for (a) pure AP ? NdCrO
3
, (b) Pure AP
Fig. 2 TEM and HRTEM
images of the NdCrO
nanocrystals
3
3
Fig. 3 SEM images and EDS spectrum of the NdCrO nanocrystals
1
23

Preparation of NdCrO
3
nanoparticles
905
1
1
20
00
aqueous solution was added drop by drop accompanied by
vigorous stirring. The solution was stirred for more than 2 h
to complete the formation of colloids. Then, the volume of
the solution was reduced by distilling out water and most of
the toluene solvent. The concentrated solution with sus-
pended colloids was washed with water and ethanol to
remove excess surfactant. The products were collected
through centrifugation. Then, the precursor was calcined at
a series of increasing temperatures ranging from 700 to
Method:50-500/10k/min/N2
dt 1.00s N2 50.0ml/min synchronization
o
3
34 C
normalized 1073.57J/g
8
6
4
2
0
0
0
0
0
(
a)
900 °C for 2 h in air.
o
o
2
2
43 C
421 C
o
3
31 C
(b)
NdCrO and AP were mixed in 2:98 (wt%), respec-
3
o
normalized 590.58J/g
tively, to prepare the samples for the thermal analysis.
43 C
100
200
300
400
500
Instrumentation
o
temperature/ C
X-ray diffraction (XRD) was carried out on a Bruker D8
3
Fig. 5 DSC curves for (a) pure AP ? NdCrO , (b) pure AP
Advance X-ray diffraction instrument (Cuk ), the diffrac-
a
tion angle (2h) from 25 to 70° was scanned. Transmission
electron microscopy (TEM) images were taken with a
JEM-200CX electron microscope, the sample was dis-
persed in aqueous ethanol by ultrasonic stirring. The BET
of toluene. After stirring overnight, the mixture became a
clear single-phase solution containing reverse micelles. To
form colloids in reverse micelles, 40 mL of 1.5 M NaOH
4
3
2
1
.00E-010
.00E-010
.00E-010
.00E-010
+
+
+
+
m/z=16,NH ,O (b)
m/z=16,NH ,O (a)
2
2
2.80E-011
2.40E-011
0.00E+000
1
00
200
300
300
300
400
400
400
500
500
500
100
200
+
300
300
300
400
400
400
500
500
500
1
.60E-010
+
+
+
4
.00E-010
.00E-010
.00E-010
.00E-010
m/z=17,NH ,OH (a)
m/z=17,NH ,OH (b)
3
1.40E-010
3
3
1
1
.20E-010
.00E-010
2
1
100
200
100
200
+
2
1
1
8
4
.00E-009
.60E-009
.20E-009
.00E-010
.00E-010
+
6.00E-010
m/z=18,H O (a)
m/z=18,H O (b)
2
2
5
.00E-010
4.00E-010
100
200
100
200
4
3
2
1
.00E-009
.00E-009
.00E-009
.00E-009
+
1.60E-011
1.20E-011
+
m/z=32,O (a)
m/z=32,O (b)
2
2
8
.00E-012
0.00E+000
100
200
300
400
500
100
200
300
400
500
o
Temperature/ C
Fig. 6 Ion current versus temperature curves of ion fragments of NH
of NH ClO evolved from (a) pure AP ? 2% NdCrO (1.5600 mg), (b) pure AP (1.5700 mg)
3 2 2
, H O and O (m/z 16, 17, 18, 32) during the thermal decomposition
4
4
3
123

9
06
Z. Yu et al.
1
8
4
.20E-009
.00E-010
.00E-010
+
m/z=30,NO (a)
+
5
4
3
.00E-011
.00E-011
.00E-011
m/z=30,NO (b)
0.00E+000
1
00
200
300
300
300
400
400
400
500
500
500
100
200
300
300
300
400
400
400
500
500
500
1
1
8
4
.60E-011
.20E-011
.00E-012
.00E-012
+
+
1
.20E-009
.00E-010
.00E-010
m/z=44,N O (a)
m/z=44,N O (b)
2
2
8
4
0.00E+000
0.00E+000
100
200
100
200
4
.00E-012
.00E-012
.00E-012
.00E-012
+
+
m/z=46,NO (b)
m/z=46,NO (a)
2
6
.00E-011
.00E-011
.00E-011
2
3
4
2
1
2
0.00E+000
100
200
100
200
o
Temperature/ C
Fig. 7 Ion current versus temperature curves of ion fragments of NO, N
NH ClO evolved from (a) pure AP ? 2% NdCrO (1.5600 mg), (b) pure AP (1.5700 mg)
2 2
O and NO (m/z 30, 44, 46) during the thermal decomposition of
4
4
3
surface areas were measured on an ASAP 2020 instrument
Results and discussion
using N adsorption at -196 °C.
2
Thermal decomposition characteristics of the sample
NdCrO samples characterization
3
were determined by a simultaneous thermal analyzer
(
Mettler Toledo, model TGA/SDTA 851e) coupled on line
The NdCrO product was characterized by XRD, TEM,
3
with a quadrupole mass spectrometry (Pfeiffer Vacuum,
model Thermostar GSD301T3), under the condition of
flowing argon gas (purity, 99.999%; flowing rate,
SEM and EDS. The XRD measurement (Fig. 1c) shows
the product is pure perovskite oxide NdCrO (900 °C)with
3
an orthorhombic structure, and the diffraction data are in
-
1
5
0 mL min ; atmospheric pressure) at the heating rate of
-
good agreement with JCPDS card of NdCrO (JCPDS no.:
3
1
1
0 °C min when the sample quantum was about 1.00 mg
71-1274). No impure peaks are observed in the XRD
pattern. The average particle size is 56 nm determined
with Al O as reference. The connection between the ther-
2
3
mobalance and the mass spectrometer was done by means of
a stainless steel capillary, maintained at 150 °C. The mass
spectrometer was operated with an electron impact ionizer
with energy 70 eV and the intensities of the m/z ranging
from 12 to 100 were monitored. DSC823E (Mettler Toledo)
from the XRD pattern parameters of the NdCrO powder
3
according to the Scherrer equation.
The TEM image in Fig. 2a shows practically monodis-
perse particles with an average size of about 60 nm, which is
consistent with the average size obtained from the peak
broadening in X-ray diffraction studied. A typical HRTEM
image is presented in Fig. 2b, showing that the nanoparticles
exhibit clearly resolved lattice fringes with the interplanar
was used at a heating rate of 20 °C/min in N atmosphere
2
over the range 20–500 °C, and all samples were placed in
aluminum pans with lids.
1
23

Preparation of NdCrO
3
nanoparticles
907
3
2
1
.00E-011
.00E-011
.00E-011
35
+
3
5
+
m/z=35, Cl (a)
1.80E-012
m/z=35, Cl (b)
1
1
.60E-012
.40E-012
1.20E-012
1
8
.00E-012
.00E-013
0.00E+000
100
200
300
400
500
100
200
300
400
500
1.40E-012
3
7
+
8
.00E-012
.00E-012
.00E-012
.00E-012
37
+
m/z=37, Cl (b)
m/z=37, Cl (a)
6
1.20E-012
4
2
1
8
.00E-012
.00E-013
100
200
300
400
500
100
200
300
400
500
4
3
2
1
.00E-011
.00E-011
.00E-011
.00E-011
5.00E-012
3
5
+
35
+
m/z=36,H Cl (a)
m/z=36,H Cl (b)
4
3
2
1
.00E-012
.00E-012
.00E-012
.00E-012
100
200
300
400
500
100
200
300
400
500
3
7
+
37
+
1
1
8
6
4
2
.20E-011
.00E-011
.00E-012
.00E-012
.00E-012
.00E-012
m/z=38,H Cl (a)
2.00E-012
m/z=38,H Cl (b)
1
1
.60E-012
.20E-012
8.00E-013
100
200
300
400
500
100
200
300
400
500
o
Temperature/ C
3
5
37
Fig. 8 Ion current versus temperature curves of ion fragments of H Cl and H Cl (m/z 36, 36, 37, 38) during the thermal decomposition
of NH ClO evolved from (a) pure AP ? 2% NdCrO (1.5600 mg), (b) pure AP (1.5700 mg)
4
4
3
spacing of 0.277 nm assigned to the (121) plane of the
The first endothermic DSC peak with a peak tempera-
ture of 242 °C is accompanied with zero weight loss. The
additives have no effects on the crystallographic transition
temperature which represents the transition from ortho-
rhombic to cubic AP [12]. Figures 4b and 5b are the TG,
DTG and DSC curves of pure AP. The first exothermic
peak with a peak temperature of 331 °C corresponding
15% weight loss is attributed to the partial decomposition
orthorhombic NdCrO structure.
3
Scanning electron micrographs shown in Fig. 3 reveal
the product is a low density, loose and porous material that
is favorable to the catalytic application. EDS was per-
formed to further confirm the composition of as-prepared
products. Figure 3b shows that the products are composed
of Nd, Cr and O with a mol ratio of 1:1:3, giving a stoi-
chiometric formula of NdCrO . The C peak in the spectrum
3
of AP and the formation of some intermediate NH and
3
is attributed to the electric latex of the SEM sample holder.
Based on the XRD, TEM, EDS analysis, the structure of
HClO by dissociation and sublimation [12, 22–24]. The
4
second exothermic DSC peak with a peak temperature of
421 °C associated with 85% weight loss is caused by the
complete decomposition of the intermediate to volatile
products [12].
NdCrO nanoparticles was obtained. The BET surface area
3
of NdCrO nanocrystals calculated from N isotherms at
3
2
2
-
196° are 10.07 m /g.
Figures 4a and 5a are the TG, DTG and DSC curves of
AP in presence of NdCrO3 catalysts. The experiment
Catalytic effect
results indicate that NdCrO has strong catalytic activity on
3
The results of the DSC and TG experiments are shown in
Figs. 4 and 5, respectively.
the thermal decomposition of AP. The first exothermic
peak at 334 °C becomes a sharp one which is associated
123

9
08
Z. Yu et al.
1
1
1
8
6
4
2
.40E-010
.20E-010
.00E-010
.00E-011
.00E-011
.00E-011
.00E-011
2.80E-012
3
5
+
35
+
m/z=70, Cl (a)
m/z=70, Cl (b)
2
2
2
2
1
1
.40E-012
.00E-012
.60E-012
.20E-012
0
.00E+000
8.00E-013
0
0
0
100
200
300
300
300
400
400
400
500
500
500
0
0
0
100
200
+
300
300
300
400
400
400
500
500
500
8
.00E-011
.00E-011
.00E-011
.00E-011
.00E-011
.00E-011
.00E-011
.00E-011
2.20E-012
2.00E-012
3
5,37
7
m/z=72, Cl (b)
3
5,37
+
2
m/z=72, Cl (a)
6
5
4
3
2
1
2
1
1
1
1
.80E-012
.60E-012
.40E-012
.20E-012
1.00E-012
8.00E-013
0
.00E+000
100
200
100
200
1
.40E-011
.20E-011
.00E-011
.00E-012
.00E-012
.00E-012
.00E-012
37
+
1.30E-012
37
+
m/z=74, Cl (a)
m/z=74, Cl (b)
1
2
2
1
.20E-012
1
8
6
4
2
1.10E-012
1
9
.00E-012
.00E-013
0
.00E+000
8.00E-013
100
200
100
200
o
Temperature/ C
3
Fig. 9 Ion current versus temperature curves of ion fragments of Cl
5
36,37
37
2
,
2 2
Cl and Cl (m/z 70, 72, 74) during the thermal decomposition of
NH ClO evolved from (a) pure AP ? 2% NdCrO (1.5600 mg), (b) pure AP (1.5700 mg)
4
4
3
with only one step weight loss on the TG curve. The second
exothermic peak is absent. The addition of NdCrO3
decreases the decomposition temperature of AP and
increases the weight loss rate as well as heat of decom-
position reaction. It can be found that adding 2% of
presence of NdCrO . AP is completely decomposed in
3
lower temperature and shorter time. Compared with the
decomposition of pure AP, the gaseous products are
instantly formed in one step with the catalysis of NdCrO3.
The products of thermal decomposition detected are HCl,
H O, N O, NH , Cl , NO, O and NO . ClO is not detected.
NdCrO nanoparticles to AP decreases the temperature of
3
2
2
3
2
2
2
2
thermal decomposition by 87 °C and increases the heat of
-
1
decomposition from 590 to 1073 J g
.
Analysis on the mechanism of thermal decomposition
of AP
The results of the TG-MS experiments are shown in
Figs. 6, 7, 8, and 9. The TG curve has clear association to
the MS curve. The detection of HCl, H O, N O, NH , Cl ,
Figure 5 shows the change of the decomposition heat for
pure and catalyzed AP. The sharp exothermic peak shown
in the DSC curves in Fig. 5a, which is indicative of rapid
chemical reaction, are confirmed by TG and MS analysis.
The catalytic activity is dependent on the specific surface
2
2
3
2
?
?
NO, O , NO , NH and O ion are observed. The dif-
2
2
2
ference between decomposition of pure AP and AP with
2
% NdCrO is shown in Figs. 6, 7, 8, and 9.
3
Figures 6, 7, 8, and 9b shows the TG-MS of pure AP.
The gaseous products of thermal decomposition are formed
in two steps. At low-temperature, products of thermal
decomposition of pure AP are NH , H O and a small
area of NdCrO . It is known the nanocrystalline can pro-
3
duce large numbers of the reaction active center. Due to the
specific surface and more reaction active centers of
3
2
amount of N O, O . At the high-temperature stage, HCl,
2
NdCrO nanoparticles, it is beneficial for the adsorption of
3
2
H O, N O, NH , Cl , NO, O , NO and a small amount of
2
O on the surface of NdCrO [25]. Therefore, nanosized
2 3
2
2
3
2
2
ClO are formed.
2
NdCrO should be considered to be the catalyst acceler-
3
Figures 6, 7, 8, and 9a show the intensity curves of ion
currents evolved during the thermal decomposition of AP in
ating both the decomposition of perchloric acid and oxi-
dation of ammonia.
1
23

Preparation of NdCrO
3
nanoparticles
909
The mechanism of catalytic action is based on the pres-
-
ence of superoxide ion (O2 ) on the surface of NdCrO [25,
‘‘REMnO
1277–84.
. Savchenko VF, Rubinchik IaS. Study of the reaction of formation
of neodymium chromite from oxides. Neorg Mater. 1979;15:122–
4.
3
’’ phases prepared in air. Mater Res Bull. 1973;8:
3
6
-
6]. During the thermal decomposition of AP, the O2 ions,
2
which are formed from the oxygen adsorbed on the surface
of the oxide, are proton traps, and they can simplify thermal
decomposition of AP. The oxidation reaction of ammonia is
happened by the collision between ammonia and the oxygen
7. Galdo
´
n A, Guillem MC. Preparation of mixed oxides MNdO3,
with M=Cr,Fe. Comparison of several methods. Solid State
Ionics. 1993;63:66–70.
8
. Devi PS. Citrate gel processing of the perovskite lanthanide
chromites. J Mater Chem. 1993;3:373–9.
absorbed on the surface of NdCrO . Increasing the partial
3
-
pressure of oxygen, the formation of O2 covered sites on
9. Kingsley JJ, Pederson LR. Combustion synthesis of perovskite
LnCrO powders using ammonium dichromate. Mater Lett.
993;18:89–96.
3
NdCrO are increased, and then the presence of oxygen can
3
1
accelerate the thermal decomposition process of AP as well
1
0. Manoharan SS, Patil KC. Combustion route to fine particle
perovskite oxides. J Solid State Chem. 1993;102:267–76.
as the oxidation of NH which increases the exothermic heat
3
of the thermal decomposition process. Figure 7 (m/z = 30,
2 3
11. Survase DV, Gupta M, Asthana SN. The effect of Nd O on
thermal and ballistic properties of ammonium perchlorate based
compostite propellants. Prog Cryst Growth Charact Mater.
4
4, 46) show that the mass spectrometric ion intensities of
nitrogen oxides (NO, N O, NO ) are bigger than those
2
2
2
002;32:161–5.
12. Said AA, AI-Qusmi R. The role of copper cobaltite spinal,
CuxCo -xO during the thermal decomposition of ammonium
during the thermal decomposition of pure AP.
3
4
perchlorate. Thermochim Acta. 1996;275:83–91.
3. Zhi J, Tian-Fang W, Shu-Fen L, Feng-Qi Z, Zi-Ru L, Cui-Mei Y,
et al. Thermal behavior of ammonium perchlorate and metal
1
Conclusions
powders of different grades.
2006;85:315–20.
4. Chen LJ, Li GS, Qi P, Li LP. Thermal decomposition of
ammonium perchlorate activated via addition of NiO nanocrys-
tals. J Therm Anal Calorim. 2008;92(3):765–9.
J
Therm Anal Calorim.
NdCrO nanocrystals synthesized by microemulsion has an
3
1
orthorhombic structure with an average size of 60 nm.
Adding 2% of NdCrO to AP can decrease the decompo-
3
sition temperature by 87 °C and increase the heat of
decomposition by 0.4 kJ g . AP was completely decom-
15. Chen LJ, Li GS, Li LP. CuO nanocrystals in thermal decompo-
sition of ammonium perchlorate stabilization, structural charac-
terization and catalytic activities. J Therm Anal Calorim.
-
1
posed in lower temperature and shorter time.
2
008;91(3):581–7.
The mechanism of catalytic action is based on the
-
presence of superoxide ion O2 on the surface of NdCrO3.
1
6. Su YL, Li SF, Ding DH. Effect of ammonium oxalate/strontium
carbonate on the burning rate characteristics of composite pro-
pellants. J Therm Anal Calorim. 2006;86:497–503.
The oxidation of adsorbed ammonia by NdCrO via the
3
1
7. Singh NB, Ojha AK. Formation of copper oxide through NaNO
KNO eutectic melt and its catalytic activity in the decomposition
of ammonium perchlorate. Thermochim Acta. 2002;390:67–72.
18. Zhu J, Chen H, Xie B, Yang X, LU L, Wang X. Preparation of
nanocrystalline Cu O and its catalytic performance for thermal
decomposition of ammonium perchlorate. Chin Catal.
004;25:637–40.
3
–
superoxide active centers takes place on the surface of
3
NdCrO . Therefore, the difference of thermal decomposi-
3
tion of AP with 2% of NdCrO and pure AP is mainly
3
caused by the different extent of oxidation of ammonium,
which results in the increase of the heat of decomposition
with the catalysis of NdCrO3.
2
J
2
1
9. Zhu W, Zhang WG, Wang HZ, Yang XJ, Lu LD, Wang X.
Synthesis and properties of shape-controlled CuO nanocrystals.
Chin J Inorg Chem. 2004;20:863–7.
Acknowledgments The authors are grateful for the financial sup-
port of the National Natural Science Foundation of China
20. Ma Z, Li F, Chen A, Bai H. Preparation and thermal decompo-
sition behavior of Fe O /ammonium perchlorate composite
nanoparticles. Acta Chimi Sin. 2004;13:1252–5.
(
(
No.50372028) and National Defense Foundation of China
No.51455030303BQ0204).
2
3
2
1. Wang YP, Yang XJ, Lu LD, Wang X. Experimental study on
preparation of LaMO
catalytic activity on NH
006;443:234–39.
3
(M=Fe, Co, Ni) nanocrystals and their
ClO decomposition. Thermochim Acta.
4
4
References
2
2
2
2
2
2
2. Rosser WA, Inami SH. Thermal decomposition of ammonium
perchlorate. Combust Flame. 1968;12:427–35.
3. Jacobs PWM, Pearson GS. Mechanism of the decomposition of
ammonium perchlorate. Combust Flame. 1969;13:419–30.
4. Jacobs PW, Russel-Jones A. Sublimation of ammonium per-
chlorate. Phys Chem. 1968;72:202–7.
5. Seiyama T, Egashira M, Iwamoto M. Some Theoretical problem
of Catalysis. Tokyo: University of Tokyo Press; 1973. p. 35.
6. Johnstone HF, Houvouras ET, Schowalter WR. Ind Eng Chem.
1
. Fernandes JDG, Melo DMA, Zinner LB, Salustiano CM, Silva
ZR, Martinelli AE, et al. Low-temperature synthesis of single-
phase crystalline LaNiO
Lett. 2002;53:121–5.
. Pe nˇ a MA, Fierro JLG. Chemical structures and performance of
3
perovskite via Pechini method. Mater
2
3
4
5
perovskite oxides. Chem Rev. 2001;101:1981–2017.
. Skinner SJ. Recent advances in Perovskite-type materials for
solid oxide fuel cell cathodes. Int J Inorg Mater. 2001;3:113–21.
. Norman AK, Morris MA. The preparation of the single-phase
1
954;46:702–8.
3
perovskite LaNiO . J Mater Process Technol. 1999;92–93:91–6.
. McCarthy GJ, Gallagher PV, Sipe C. Crystal chemistry of cata-
lyst materials. I. Composition and unit cell parameters of
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