Direct synthesis of LPG from carbon dioxide over hybrid catalysts comprising modified methanol synthesis catalyst and β-type zeolite

Article abstract of DOI:10.1016/j.apcata.2014.01.025

Hydrogenation of carbon dioxide to C₃ and C₄ paraffins (LPG) was studied by using hybrid catalysts composed of Zr-modified Cu-Zn catalyst with Pd-modified β zeolite. Various factors that affect catalyst activity, including reaction t

Full text of DOI:10.1016/j.apcata.2014.01.025

Applied Catalysis A: General 475 (2014) 155–160
Contents lists available at ScienceDirect
Applied Catalysis A: General
journal homepage: www.elsevier.com/locate/apcata
Direct synthesis of LPG from carbon dioxide over hybrid catalysts
comprising modified methanol synthesis catalyst and ␤-type zeolite
∗
Congming Li, Xingdong Yuan, Kaoru Fujimoto
Japan Gas Synthesis Co. Ltd, 5-20, Kaigan 1-Chome, Minato-Ku, Tokyo, 105-8527, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
Hydrogenation of carbon dioxide to C3 and C4 paraffins (LPG) was studied by using hybrid catalysts
composed of Zr-modified Cu–Zn catalyst with Pd-modified ␤ zeolite. Various factors that affect cata-
lyst activity, including reaction temperature, space velocity, pressure, and the ratio of H2 to CO2 were
investigated thoroughly. The hybrid catalysts exhibited stable activity over 100 h and extraordinary high
Received 6 November 2013
Received in revised form 8 January 2014
Accepted 10 January 2014
Available online 21 January 2014
◦
selectivity of LPG synthesis (especially iso-butane) even under low temperature (260 C) and low pressure
(
2 MPa). Conversion of CO2 and the yield of hydrocarbon reached 25.2% and 13.3%, respectively, while
keeping the selectivity of LPG and CH4 75% and 1%, respectively. The iso-butane/n-butane ratio was about
6/1, whose value was much higher than that of thermodynamic equilibrium (about 1/1).
Keywords:
Carbon dioxide
Iso-butane
Hybrid catalysts
1
©
2014 Elsevier B.V. All rights reserved.
1
. Introduction
Carbon dioxide is one of the most abundant and widely dis-
hydro-condensation of methanol or dimethylether (DME) on mod-
ified ␤-zeolite can make LPG-rich paraffin mixture with little dry
◦
gas (CH + C H ) formation at temperature as low as 300 C or lower
4
2
6
tributed carbon resources, and has become the focus of attention
because of its greenhouse effects [1–3]. Therefore, the utilization of
CO is desirable for the effective method for reducing CO emission.
Many kinds of strategies with this regard have been proposed to
solve this intractable problem. Among various methods, recycling
technology by the hydrogenation of CO2 has attracted additional
attention as a possible way to manufacture fuel material or useful
[17]. The hybrid catalyst composed of methanol synthesis cata-
lyst and modified zeolite give LPG-rich paraffins selectively from
synthesis gas with much higher conversion for methanol synthesis
reaction. The catalyst could work over 2000 h without regeneration
[18]. However, the reaction of syngas to LPG gave only half of the
converted CO to target product because of the CO shift reaction of
the product . Direct synthesis of LPG from CO2 hydrogenation is an
important choice for converting the most common and unlimited
carbon resource to high-value-added products. We have reported
previously that Zr-modified Cu–Zn–Al catalyst (CZZA) show high
activity and good stability for methanol synthesis [19]. As catalyst
component for hydro-conversion of methanol to LPG, a modified
␤-zeolite was regarded as the most suitable one in our previous
work [20,21].
2
2
chemicals. The conversion of CO to methanol by its hydrogenation
2
has been the subject of intense study over the past decades [4–12].
However, the reaction is regulated by the severe limitation of ther-
modynamic equilibrium. To overcome such a limitation, the in situ
transformation of methanol to stable materials is a reasonable way
to improve the reaction performance. One of the typical methods
to make hydrocarbon is the methane formation, which is the only
thermodynamically favorable reaction. Another is the modified
Fischer–Tropsch (F–T) reaction [13]. However, the F–T type reaction
The present paper is the results of the trial of the selective syn-
thesis of LPG over the hybrid catalysts consisting of a Zr-modified
Cu–Zn–Al methanol catalyst with modified ␤ zeolite (Pd-␤). The
results show that the catalyst is active at low temperature, stable
of CO2 makes CH -rich hydrocarbon mixture. Liquefied petroleum
4
gas (LPG), a general description of propane and butane, has envi-
ronmentally benign characteristics and widely used as clean fuels.
Besides, LPG is a good substitute for fuel in spark ignition engines,
and used as a replacement for aerosel propellants and refrigerants,
etc. [14–16]. So LPG synthesis from carbon dioxide and hydrogen is
an important selection to fixation of carbon dioxide to fuels as well
as useful chemicals. One of the present authors has shown that the
and selective for the synthesis of LPG-rich paraffins from CO . The
2
process of hydrocarbon formation and the product distribution are
discussed in detail.
2. Experimental
2.1. Catalyst preparation
∗ Corresponding author. Tel.: +81 695 3202; fax: +81 695 3309.
E-mail address: fujimoto070@gmail.com (K. Fujimoto).
Modified Cu–Zn methanol synthesis catalyst was prepared by
the co-precipitation sedimentation method. For convenience, these
0
926-860X/$ – see front matter © 2014 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.apcata.2014.01.025

1
56
C. Li et al. / Applied Catalysis A: General 475 (2014) 155–160
catalysts will be designed by an abbreviation, CZA (Cu/ZnO/Al O ),
2
3
CZZA (Cu/ZnO/ZrO /Al O ), CZZ (Cu/ZnO/ZrO ) throughout this
2
2
3
2
paper [19]. The resulting catalyst has the composition of CZA
Cu/ZnO/Al O = 4/3/3), CZZA (Cu/ZnO/ZrO /Al O = 4/3/1.5/1.5),
(
2
3
2
2
3
CZZ (Cu/ZnO/ZrO = 4/3/3) by weight. A Pd-modified ␤ zeolite
2
(
NH -␤, Si/Al = 38) (Pd/␤) was prepared by ion exchange with nitric
4
◦
acid solution of PdNO for 24 h, then dried at 100 C overnight and
calcining at 500 C for 4 h. The loading amount of Pd was 0.1 wt%.
3
◦
Methanol synthesis catalysts and the Pd-␤ were independently
pelletized, crushed and sieved to the particles of 0.36–0.71 mm,
respectively. The two kinds of particles were then mechanically
mixed well to form hybrid catalyst of CZA/Pd-␤, CZZA/Pd-␤ and
CZZ/Pd-␤.
Fig. 1. Equilibrium conversion of CO2 for different products as a function of tem-
perature. Pressure: 2.0 MPa, H2/CO2 = 3/1 (mole ratio).
2.2. Catalyst characterization
The XRD (X-ray diffraction analysis) measurement was per-
of 3 in the reaction (1), the equilibrium conversion of CO2 is higher
formed with a Rigaku diffractometer equipped with a Cu–K␣
radiation. The specific surface area of the catalysts was determined
by BET method using a Micromeritics ASAP 2010. Temperature pro-
grammed reduction of methanol synthesis catalyst were conducted
by the procedure written in the preceding paper [19].
than 80%, while those of CH OH or DME is much lower.
3
4
CO + 13H → C H + 8H O
(1)
2
2
4
10
2
It has been shown that the hydro-condensation of methanol
can make C3 and C4 hydrocarbons with high selectivity [22]. The
formation of hydrocarbons relieves the thermodynamic constraint
inherent to methanol synthesis by in situ transforming methanol
into hydrocarbons. Thus, the high conversion of CO2 to hydrocar-
bons can be expected.
2
.3. Catalytic reaction test
A pressurized flow type reaction apparatus with a fixed-bed
reactor was used for this study. The apparatus was equipped with
an electronic temperature controller for a furnace, a tubular reactor
with an inner diameter of 8 mm, thermal mass flow controllers for
gas flows and a back-pressure regulator. A thermocouple was set
at the axial center of the tubular reactor. 1 g of catalyst was placed
in the reactor with inert quartz sands above and under the cata-
3.3. CO2 hydrogenation to LPG on a variety of hybrid catalysts
Table 1 showed the catalytic performance at the steady state in
CO2 hydrogenation over various hybrid catalysts. Neither alkenes
noraromaticswere obtainedover the hybridcatalysts. It is apparent
that CZZA/Pd-␤ exhibits the highest conversion of CO2 and espe-
cially the yield of hydrocarbon was almost two times higher than
that of Zr-free catalyst (CZA/Pd-␤). This is probably due to higher
productivity of methanol synthesis over CZZA catalyst than that
over CZA [19].
lyst. All catalysts were reduced in a flow of 5% H in nitrogen at
2
2
◦
50 C for 4 h before the reaction. The steady-state activity mea-
surements were taken after 15 h on the stream. All the products
from the reactor were introduced in gaseous state and analyzed by
gas chromatograph (GC). CO, CH4 and CO2 were analyzed by a GC
equipped with the thermal conductivity detector (TCD) and a col-
umn of activated charcoal, and light hydrocarbons were analyzed
by another GC equipped with the flame ionization detector (FID)
and a capillary column of Porapak-Q.
◦
The hydrocarbon yield obtained over CZZA/Pd-␤ at 260 C was
much higher than that obtained at higher temperature (Fig. 4) for
LPG (C3 + C4) selectivity of about 75% accompanying lower methane
selectivity (1.2%). However, its level was much lower than that of
the syngas conversion (45.5%) under the same reaction conditions.
These subjects will be discussed in the later section. The low content
3
. Results and discussion
3.1. Catalyst characterization
Table 1
The calcined CZZA exhibited the highest surface area of
06.3 m /g, and CZZ (90.9 m /g) and CZA (78.3 m /g) followed. The
CO2 hydrogenation over hybrid catalysts.
2
2
2
1
Catalysts
CZA/Pd-␤
CZZ/Pd-␤
CZZA/Pd-␤
CZZA/Pd-␤
CZZA
19.0b
result of N O titration indicate that the aluminum-containing cat-
2
CO2 Conv. (%)
21.2
22.0
25.2
82.8a
alyst (CZA) had the highest Cu surface area, while TPR result shows
the reduction peak of CZA obviously shifted to high temperature
compared with CZZA. All these phenomena suggest that as it is
well-known the added Al O promotes the CuO dispersion and sup-
Yield(%)
H.C.
CO
MeOH
DME
7.5
13.7
0
11.2
10.8
0
13.3
11.9
0
45.5
37.2
0
tr
17.2
1.8
0
2
3
presses its reduction, whereas the added ZrO2 in CuO/ZnO-based
catalyst promote the reduction of CuO with H2 [19].
tr
tr
tr
tr
H.C. composition
C1
C2
C3
C4
C5
C6
3.7
5.0
21.1
60.4
10.3
tr
tr
9.8
80.5
3.8
4.9
17.8
56.9
12.3
2.3
tr
9.1
76.7
1.2
2.8
12.0
62.8
14.8
4.5
1.9
16.0
74.8
0.1
0.5
5.8
85.2
6.4
1.2
0.7
46.7
91.0
–
–
–
–
–
–
–
–
–
3
.2. Catalytic results
For the direct synthesis of hydrocarbons from CO , there are
2
three important reactions involved: (i) methanol formation from
CO2 hydrogenation and/or CO hydrogenation, (ii) dehydration of
methanol to DME, (iii) hydrocondensation of DME to hydrocarbons,
and (iv) reversed water gas shift (RWGS) reaction . Since the target
C7+
i-C4/n-C4
LPG Sel. (%)
of our study is the synthesis of LPG from CO , the hydrocarbons
◦
2
Reaction temp., 260 C; pressure, 20 atm; W/F, 10 g cat h/mol; H /CO , 3/1.
2
2
should be C3 and C4 parraffin with low C + C2 paraffins. As shown
a
H /CO = 2.0.
1
2
b
in Fig. 1, when butane is synthesized from CO with the ratio H /CO
Without Pd-␤ zeolite.
2
2
2

C. Li et al. / Applied Catalysis A: General 475 (2014) 155–160
157
reaction, suggesting a part of Cu metal was oxidized during the
reaction. By using Debye–Scherrer formula, the crystallite size
growth of Cu occurred during stability test, which could be esti-
mated to be 39.2 nm, which grew from 9.4 nm of fresh catalyst,
larger than 100 h test of methanol synthesis (11.4 nm) [19], still
keeping the CO2 conversion constant.
3
3
.5. Effect of reaction conditions
.5.1. Temperature
The most suitable reaction temperature for methanol synthesis
◦
over the current catalysts was approximately 230 C, which differs
substantially from that of the methanol conversion reaction over
zeolite. The catalytic activity was tested using the composite cata-
◦
lyst CZZA/Pd-␤ (1/1 weight ratio) at 260, 270 and 280 C as shown
◦
in Fig. 4. With increasing reaction temperature from 260 to 280 C,
the conversion of CO2 decreased slightly, while the yield of hydro-
carbons markedly decreased and that of CO increased. Typically,
the methanol synthesis function is provided by a Cu-based cata-
lyst while the dyhydrogenation of methanol to DME and then to
hydrocarbons is afforded by modified zeolite. In general, zeolite
is preferred at higher temperature for a substantially high activ-
ity, while methanol synthesis is favored for lower temperature
from the thermodynamically standpoint as shown in Fig. 1, and it
was realized in the experiment [19]. In order to attain a good syn-
ergy between the two catalysts, a suitable reaction temperature is
◦
Fig. 2. Stability of CO2 hydrogenation to LPG over CZZA/Pd-␤ catalyst at 260 C,
W/F = 10 g cat h/mol, H2/CO2 = 5/1.
◦
important. Below 260 C, almost the entire product was DME and
of methane in the products is quite favorable from the industrial
stand point.
CO (not shown), while higher temperature do also tend to favor CO
◦
formation. So we think 260 C is beneficial to obtaining high activity
and higher LPG selectivity.
3.4. Catalyst stability
It was found that with increasing the reaction temperature, the
LPG selectivity decreased and the methane selectivity increased.
Therefore, we consider that the relative lower temperature is suit-
able for obtaining high yield of LPG.
As shown in Fig. 2, hybrid catalysts keep a constant activity
CO2 conversion) up to 100 h from the start of the reaction. How-
ever, with the time on stream, the DME becomes the main product
(
with trace methanol while keeping CO conversion constant, which
should be ascribed to the poisoning of acid site by water molecule
2
3.5.2. W/F
The conversion of CO2 and yield of hydrocarbons increased
monotonously with increasing the time factor (W/F) as shown in
on the zeolite. Successing the CO2 hydrogenation, the CO –H2 gas
2
was swiched to syngas (H /CO/CO = 8/3/1) and operated the syn-
2
2
◦
gas reaction at 260 C and W/F = 10 g cat h/mol for 30 h and again
CO –H gas was fed to see what happened. It was interesting to
2
2
note that the activity was recovered without any obvious activity
and selectivity attenuation after 100 h stability.
Fig. 3 shows the result of XRD measurement of the used hybrid
catalyst after 100 h run. Results obtained suggest the presence of
◦
◦
a CuO phase (2ꢀ = 35.5 , 38.5 ) for calcined sample. After reduc-
◦
◦
tion, the peaks at 43 and 50 were attributed to metallic Cu, which
performed as a role as active component for methanol synthesis
◦
[
23,24]. The peak attributed to CuO was observed at 36.4 after
Fig. 3. XRD patters of catalysts: (1) calcined; (2) reduced; (3) after 100 h reaction,
and (4) Pd-␤ zeolite.
Fig. 4. Effect of reaction temperature on CO2 hydrogenation to LPG over CZZA/Pd-␤
catalyst at 2 MPa, W/F = 10 g cat h/mol, H2/CO2 = 3/1.

1
58
C. Li et al. / Applied Catalysis A: General 475 (2014) 155–160
Fig. 6. Effect of H2 to CO2 ratio on CO2 hydrogenation to LPG over CZZA/Pd-␤ catalyst
◦
at 260 C, 2 MPa, W/F = 10 g cat h/mol.
next catalytic reaction of methanol to hydrocarbons. The catalytic
behavior as a function of total pressure of H /CO feed mixture was
2
2
investigated between 1 and 2.5 MPa as shown in Fig. 7. The conver-
sion of CO2 is promoted by increasing the reaction pressure. It is
worth noting that this catalyst exhibits high activity even under
relative low pressure. At 1.0 MPa, the CO2 conversion was 23.3%
and slightly increased to reach 32.5% at 2.5 MPa, while the hydro-
carbon yield increased from 4.7% at 1.0 MPa to 21.4% at 2.5 MPa.
Since the process was controlled by the kinetics, a high pressure,
which meant that the high concentration of reactants was obtained
on the surface of catalyst. At the same time, increasing reaction
pressure actually prolonged the residence time of reactant in the
catalyst bed, which is preferable for close contact between reactant
and catalyst, resulting in the high conversion of CO2 to hydrocar-
bons. The selectivity of LPG reaches as high as 80% in the pressure
range tested.
◦
Fig. 5. Effect of W/F on CO2 hydrogenation to LPG over CZZA/Pd-␤ catalyst at 260 C,
MPa, H2/CO2 = 3/1.
, * and ×: CO2 hydrogenation to methanol under the same reaction conditions.
2
᭹
Fig. 5. At short contact time below 5 g cat h/mol, CO was the main
product. With an increase in the contact time beyond 5 g cat h/mol,
CO did not increase but slightly decreased to reach a constant level.
This means that CO2 is converted to CO and hydrocarbon, then CO
is successively converted to hydrocarbon.
Also hydrocarbon distribution vs. contact time (Fig. 5) shows
that it is almost constant but C6+ hydrocarbon is gradually
decreased and C3 hydrocarbon increased.
3
.5.3. H /CO2 ratio
2
The ratio of H /CO had a great effect on the activity and selectiv-
2
2
ity of the catalyst. The stoichiometric ratio of H2 of H /CO2 to form
2
paraffin from CO2 is between 3 and 4 as described in the following
equation.
CO + (3 + 1/n)H → 1/n(CnH
) + 2H O (n = 4forC H10)
2
2
2n+2
2
4
Effects of the molar ratio of H2 to CO2 are given in Fig. 6. As the
molar ratio of H2 to CO2 increased, the apparent conversion of CO2
increased slightly while the relative selectivity of CO decreased,
probably because that of methanol (which is the intermediate
species for hydrocarbon synthesis) increased with increasing the
H2 concentration from the stand point both thermodynamics and
kinetics [19]. The hydrocarbon distribution was also affected as
shown in Fig. 6. Increasing the H /CO ratio increased the LPG selec-
2
2
tivity from 74.8% H /CO ratio of 3 to 78.6% H /CO2 ratio of 4, and
2
2
2
then kept a relatively stable LPG selectivity when continuing the
H /CO2 ratio.
2
3.5.4. Pressure
From the dynamics stand point, a high pressure is beneficial
for the methanol synthesis from CO2 hydrogenation and for the
Fig. 7. Effect of pressure on CO2 hydrogenation to LPG over CZZA/Pd-␤ catalyst at
260 C, W/F = 10 g cat h/mol, H2/CO2 = 5/1.
◦

C. Li et al. / Applied Catalysis A: General 475 (2014) 155–160
159
makes the large temperature difference for the hydrocarbon for-
mation with Pd (for hydrogen activation) containing zeolite and
Pd-free zeolite catalyst [27,28]. Thus the reactivity of three active
species with carbene is in the reverse order. Only small amount of
active species of C1 (CH3+) may come out of the zeolite as methane
because of its high reactivity [29].
Active species of C3 or higher, may have chance to come out
of zeolite surface as hydrocarbons. In the case of C4 species, two
types of active species could exist, that is secondary butyl carbe-
nium ion and tertiary butyl carbenium ion. The latter species is by
about 58.6 kJ/mol more stable than the former one and thus may be
predominant in its concentration over the former one. Its predomi-
nance is demonstrated by the fact that the amount of iso-butane in
the product is by about 16 times higher than that of n-butane. And
the tertiary butyl carbenium ion would be very low in its reactivity
for chain growth and thus most of them come out of catalyst surface
as branched C4 hydrocarbons without growing to C5+ species.
Fig. 8. Reaction path of CO2 hydrogenation to hydrocarbons over hybrid catalysts.
4
. Discussions on the CO2 hydrogenation on the hybrid
catalyst
The overall reaction path of the hydrocarbon synthesis can be
shown in Fig. 8. As previously reported [19], the methanol for-
mation from CO2 on CZZA catalyst was assumed to pass through
two routes: one is the direct hydrogenation of CO2 to methanol;
another is the route which passes through the CO formation,
while the conventional methanol synthesis catalyst (CZA) passes
through the CO formation. Methanol is formed by CO2 hydro-
genation or via CO over the methanol catalyst, then methanol is
5. Conclusion
Hybrid catalysts consisting of Zr modified Cu–Zn catalyst with
converted to DME and then converted directly to C –C7 paraffins
1
Pd-modified ␤ zeolite were found to show high and stable conver-
sion for CO2 hydrogenation. The stable activity of CO2 conversion
can be attributed to the high water resistant of CZZA. The hybrid cat-
alyst consisting of CZZA with Pd-␤ was effective for LPG synthesis
with selectivity as high as 75% and with little methane formation.
Catalytic activity was stable over 100 h. Due to the poisoning of acid
site by water molecule on the zeolite, DME became the main prod-
uct with trace methanol with the time on stream. But the bad effects
could be overcome if the Pd-␤ was exposed to the “dry” conditions
on the acidic sites of the Pd-␤ zeolite according to mechanism
of chain growth with the strong promotion effect of spillover of
hydrogen [25]. The spillover of hydrogen makes it possible to con-
vert methanol into paraffinic hydrocarbons at temperature as low
◦
as 260 C.
The essential factors for the selective synthesis of LPG:
(
1) excellent activity of methanol formation and resistance of CZZA
to steam [19];
(CO–H2 reaction). Iso-butane could be obtained in extra-ordinary
(
(
2) easy transfer of methanol from CZZA to Pd-␤ zeolite;
3) large pores in beta zeolite (∼0.7 nm) enable the quick diffu-
sion of methanol and product hydrocarbon which suppress the
secondary reactions within the interior of the pore system;
high selectivity and in good yields over these novel composite cat-
alysts by the hydrogenation of carbon dioxide. The essentials of
the high activity at low temperature and the high selectivity of
aimed products may be caused by the promotion effect of hydro-
gen spillover and its effective reaction with the intermediates on
zeolite. These results indicated that the proper use of methanol
catalyst with zeolite enabled us to produce specified hydrocarbons
from CO2.
+
−
(
4) introduction of H species (H and or H ) to Pd-␤ zeolite, by the
hydrogen spillover [26].
The high selectivity of C3 and C4 paraffins are interpreted
as follows: the active species of the methanol conversion to
hydrocarbons are accepted as carbene CH2 and carbenium ions.
The thermodynamical stability of carbenium ion is the ascend-
Acknowledgement
ing order: CH3+ « C H5 < sec- C H7 < sec-C H9 « tert-C H9 . These
+
+
+
+
2
3
4
4
This work was supported by New Energy and Industrial Tech-
nology Development Organization (NEDO).
carbenium ions come out of the zeolite through two possible routes
as shown in Fig. 9). One is the de-protonation for making olefin:
(
+
+
C4H9 → C H + H
(2)
4
8
References
Another is the hydrogenation to make parraffin:
[
1] C.S. Song, Catal. Today 115 (2006) 2–32.
C4H9+ + H− → C H
[2] W. Wang, S.P. Wang, X.B. Ma, J.L. Gong, Chem. Soc. Rev. 40 (2011) 3703–3727.
(3)
4
10
[
[
3] R.W. Dorner, D.R. Hardy, F.W. Williams, H.D. Willauer, Energy Environ. Sci. 3
2010) 884–890.
(
It is clear that reaction (2) is much more endothermic than reac-
tion (3). The olefin formation from methanol (MTG reaction, which
include reaction (2) required high temperature (>350 C). On the
other hand, reaction (3) is large exothermic reaction, and thus pro-
ceeds at lower temperature. The difference in the thermodynamic
4] F.L. Liao, Y.Q. huang, J.W. Ge, W.R. Zheng, K. tedsree, P. Collier, X.L. Hong, S.C.
Tsand, Angew. Chem. Int. Ed. 50 (2011) 2162–2165.
◦
[5] J. Toyir, P.R. Piscina, J.L.G. Fierro, N. Homs, Appl. Catal., B Environ. 29 (2001)
07–215.
6] C. Yang, Z.Y. Ma, N. Zhao, W. Wei, T.D. Hu, Y.H. Sun, Catal. Today 115 (2006)
22–227.
7] J. Wambach, A. Baiker, A. Wokaun, Phys. Chem. Chem. Phys.
071–5080.
8] H.W. Lim, M.J. Park, S.H. Kang, H.J. Chae, J.W. Bae, K.W. Jun, Ind. Eng. Chem. Res.
8 (2009) 10448–10455.
9] N. Tsubaki, I. Motoaki, K. Fujimoto, J. Catal. 197 (2001) 224–227.
2
[
[
[
[
2
1
(1999)
5
4
[
[
[
10] L. Fan, K. Fujimoto, J. Catal. 172 (1997) 238–242.
11] Q.L. Tang, Q.J. Hong, Z.P. Liu, J. Catal. 263 (2009) 114–122.
12] F. Arena, K. Barbera, G. Italiano, G. Bonura, L. Spadaro, F. Frusteri, J. Catal. 249
(
2007) 185–194.
[
[
[
13] W. Wang, S. Wang, X. Ma, J. Wang, Chem. Soc. Rev. 40 (2011) 3703–3727.
14] A. Simons, S. Nunoo, Pet. Sci. Technol. 27 (2009) 2223–2233.
15] M.A. Ceviz, F. Yuksel, Renew. Energy 31 (2006) 1950–1960.
Fig. 9. Reaction scheme of CO2 hydrogenation to hydrocarbons over Pd-␤ zeolite.
[16] Z.M. Liu, L.G. Li, B.Q. Deng, Energy Convers. Manage. 48 (2007) 395–404.

1
60
C. Li et al. / Applied Catalysis A: General 475 (2014) 155–160
[
[
17] K. Asami, Q. Zhang, X. Li, S. Asaoka, K. Fujimoto, Catal. Today 106 (2005)
47–251.
18] K. Fujimoto, C.M. Li, X.D. Yuan, M. Takashiro, Y. Kazuo, The 10th Natural Gas
Conversion Symposium, Poster, Doha, 2–7 March, 2013.
19] C.M. Li, X.D. Yuan, K. Fujimoto, Appl. Catal., A Gen. 469 (2014) 306–311.
20] Q.W. Zhang, X.H. Li, K. Asami, S. Asaoka, K. Fujimoto, Fuel Process. Technol. 85
[24] C. Yang, C.A. Mims, R.S. Disselkamp, J.H. Kwak, C.H. FerricPeden, C.T. Campbell,
J. Phys. Chem., C 114 (2010) 17205–17211.
[25] K. Fujimoto, Y. Yu, Stud. Surf. Sci. Catal. 77 (1993) 393–396.
[26] R. Ueda, T. Kusakari, K. Tomishige, K. Fujimoto, J. Catal. 194 (2000) 14–22.
[27] A. Zhang, I. Nakamura, K. Aimoto, K. Fujimoto, Ind. Eng. Chem. Res. 34 (1995)
1074–1080.
2
[
[
(
2004) 1139–1150.
[28] K. Fujimoto, H. Saima, H. Tominaga, J. Catal. 94 (1985) 16–23.
[29] K. Fujimoto, H. Satma, H. Tominaga, Stud. Surf. Sci. Catal. 28 (1986)
875–877.
[
[
[
21] Q.J. Qe, Y. Lian, X.D. Yuan, X.H. Li, K. Fujimoto, Catal. Commun. 9 (2009) 256–261.
22] W. Zhu, X. Li, H. Kaneko, K. Fujimoto, Stud. Surf. Sci. Catal. 167 (2007) 355–360.
23] J. Yoshihara, C.T. Campbell, J. Catal. 161 (1996) 776–782.