Highly efficient hydrogenation of carbon dioxide to methyl formate over supported gold catalysts

Article abstract of DOI:10.1039/c4gc01818d

Transformation of carbon dioxide (CO₂) into valuable chemicals is an interesting topic in green chemistry. Hydrogenation of CO₂ to methyl formate (MF) in the presence of methanol is an important reaction. In this work, Au nanocatalysts immobilized on different supports were prepared and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectrometry (XPS). The catalytic performances of the catalysts for the reaction were studied. It was demonstrated that the Au/ZrO₂, Au/CeO₂ and Au/TiO₂ were very active and selective for the reaction in the absence of any basic additives. The Au/ZrO₂ was more active than Au/CeO₂ and Au/TiO₂ if the sizes of Au particles on the supports were similar. Moreover, for the Au/ZrO₂ catalysts, Au particles with smaller size had higher activity. The possible mechanism of the catalytic reaction was proposed.

Full text of DOI:10.1039/c4gc01818d

View Article Online
View Journal
Green
Chemistry
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: Prof. B. Han, C.
Wu, Z. Zhang, Q. Zhu, H. Han and Y. Yang, Green Chem., 2014, DOI: 10.1039/C4GC01818D.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the Ethical guidelines still
apply. In no event shall the Royal Society of Chemistry be held
responsible for any errors or omissions in this Accepted Manuscript
or any consequences arising from the use of any information it
contains.
www.rsc.org/greenchem

Page 1 of 6
Green Chemistry
View Article Online
Highly efficient hydrogenation of carbon dioxide to methyl formate over
DOI: 10.1039/C4GC01818D
supported gold catalysts
Congyi Wu, Zhaofu Zhang,* Qinggong Zhu, Hongling Han, Yingying Yang and Buxing Han*
2
Transformation of carbon dioxide (CO ) into valuable chemicals is an interesting topic in green chemistry.
Hydrogenation of CO to methyl formate (MF) in the presence of methanol is an important reaction. In this
2
work, Au nanocatalysts immobilized on different supports were prepared and characterized by X-ray
diffraction (XRD), transmission electron microscope (TEM) and X-ray photoelectron spectrometer (XPS).
The catalytic performances of the catalysts for the reaction were studied. It was demonstrated that the
Au/ZrO , Au/CeO and Au/TiO were very active and selective for the reaction in the absence of any basic
2
2
2
additives. The Au/ZrO was more active than Au/CeO and Au/TiO if the sizes of Au particles on the
2
2
2
supports were similar. Moreover, for the Au/ZrO catalysts, Au particles with smaller size had higher
2
activity. The possible mechanism of the catalytic reaction was proposed.
Au as the catalyst, MF can be formed by hydrogenation of CO
the presence of methanol without any basic additive. CeO , TiO
and ZrO are commonly used supports for hydrogenation of
carbon dioxide.
with H and methanol to produce MF. It was found that the
2
in
2
,
Introduction
2
2
Carbon dioxide (CO
other hand, it is also a nontoxic, abundant and inexpensive carbon
source. Transformation of CO into value-added chemicals is of
vital importance. Different routes have been developed for the
2
) is the major greenhouse gas. On the
3c,5c
In this work, we studied the reaction of CO
2
2
2
2 2 2
supported gold catalysts Au/CeO , Au/TiO , and Au/ZrO had
very activity and selectivity for the reaction without use of any
1
conversion of CO into valuable products, such as urea, formic
2
base. Especially, the Au/ZrO with small Au particles was very
2
2
3
4
5
acid, methanol, carbonate and dimethylformamide. With the
active and selective for the reaction.
6
progress in hydrogen generation from biomass and splitting of
water by photocatalysis, hydrogenation of CO2 to produce
various chemicals will receive more and more attention.
7
H +CO +CH OH→HCOOCH +H O
(1)
2
2
3
3
2
Methyl formate (MF) is an important chemical with wide
Results and discussion
8
,9
applications. Currently, MF is produced by carbonylation of
1
0
methanol with CO or by methanol dehydrogenation. Synthesis
of MF from CO , H and methanol, which is shown in Equation
1), has been studied by different researchers. For example,
In this work, we prepared Au/CeO
established deposition-precipitation method.
procedures are described in Experimental section. In preparation
of the Au/ZrO catalysts, the pH values of the solutions were
controlled at 9.0 and 10.5, respectively, and the corresponding
catalysts are denoted as Au/ZrO -9.0 and Au/ZrO -10.5. The
reduced Au/CeO , Au/ZrO -9.0, Au/ZrO -10.5, and commercial
2
and Au/ZrO
2
using well
2
6,27
2
2
The detailed
(
1
1
Jessop et al. used RuCl
and the TON could be 3500 in 60 hrs. Baiker and co-workers
carried out the reaction promoted by [RuCl (dppe) ]. Federsel et
2
(PMe
3
)
4
as the catalyst to synthesize MF
2
1
2
2
2
2
2
1
3
al. studied the reaction using bio-inspired iron based
2
2
2
homogeneous catalyst and a TON of 292 for MF was obtained.
Au/TiO catalyst were characterized by X-ray diffraction (XRD),
transmission electron microscope (TEM) and X-ray
photoelectron spectrometer (XPS).
The TEM images of the catalysts are illustrated in Fig. 1. The
sizes of the Au particles in the catalysts were evaluated by
counting two hundred particles, and the size distributions are also
presented in the figure. The average diameters of gold particles in
2
1
4
Heldebrant
reported capture of CO2 and subsequent
homogeneous hydrogenation of CO2 to MF catalyzed by
RuCl (PPh ) /DBU system. For these homogenous catalysts, a
2
3 3
base (e.g. triethylamine) was used in the reaction.
Heterogeneous catalysts have also been utilized to promote
the reaction. It was shown that silica hybrid gel supported
RuCl
using triethylamine as the base. Tsang et al.
that Pd/Cu/ZnO and Cu/ZnO catalyst systems could fix CO
2
[PMe
2
(CH
2
)
2
Si(OEt)
3
]
3
was very effective for the reaction
the Au/CeO
nm, 2.6 nm, 1.9 nm, and 2.4 nm, respectively.
2
, Au/TiO
2
, Au/ZrO
2
-9.0 and Au/ZrO
2
-10.5 were 2.5
1
5
16,17
demonstrated
into
30
2
(b)
MF in the absence of bases, but the catalytic activity was low and
(
a)
20
by-product CO was produced. Xin and co-workers et al. reported
1
8
photocatalytic reduction of CO to MF using ZnS and
10
0
2
1
9
CuO/TiO2 as the catalysts. A study of photocatalytic reduction
was also conducted over Bi prepared by solvothermal
S
2 3
1
2
3
4
Particle diameter (nm)
2
0
method.
Gold based catalysts have attracted much attention due to
their unique catalytic performance in oxidation of carbon
3
0
20
10
0
(
d)
(c)
2
1
22,23
monoxide, hydrogenation of unsaturated compounds
and
2
4
low temperature water gas shift reaction. It was reported that
Au/TiO could catalyze hydrogenation of CO to formic acid in
2
2
2
5
1
2
3
4
the presence of an amine. Formic acid can react with methanol
to produce MF by esterification reaction. We expect that using
Particle diameter (nm)

Green Chemistry
Page 2 of 6
View Article Online
30
DOI: 10.1039/C4GC01818D
(
f)
(
e)
The turnover frequencies (TOFs, moles of MF formed per
hour per mole of Au) of the reaction catalyzed by the Au
nanocatalysts on different supports are compared in Fig. 4a. As
discussed above, the Au particles in the Au/CeO , Au/TiO ,
2
0
10
2
2
0
1
2
3
4
Au/ZrO -10.5 have similar size. It can be concluded from the
2
Particle diameter (nm)
results in Fig. 4a that the activity of the Au particles on the ZrO
was considerably higher than that on the TiO or CeO when the
size of the Au particles was similar. In general, CeO is
2
30
20
10
0
2
2
(
g)
(h)
2
2
9-31
considered as basic and TiO
amphoteric nature. Therefore, the main reason for the higher
2
is nearly neutral
2
while ZrO has
3
2
activity of the Au particles on the ZrO may be that the basic sites
2
1
2
3
4
2
facilitate the adsorption and activation of CO and the acidic sites
Particle diameter (nm)
promote desorption of formed formic acid, which will be
discussed in the following.
Fig. 1 The TEM images of catalysts and the size distributions of the Au
particles. (a) and (b) Au/CeO ; (c) and (d) Au/TiO2; (e) and (f)
Au/ZrO -9.0; (g) and (h) Au/ZrO -10.5.
2
Fig. 4a also shows that the activity of the Au/ZrO -9.0 is
2
2
2
2
higher than that of the Au/ZrO -10.5. The main difference of the
Fig. 2 gives the XRD patterns of the catalysts. All the
samples show characteristic peaks of corresponding supports
two catalysts is that the Au particles in the former have smaller
size. This indicates that smaller size of the Au particles is
favourable to accelerate the reaction. In this work, the effects of
various factors on the reaction were further studied using
(
TiO , CeO and ZrO ). For all of the four catalysts, the peak of
2 2 2
the gold particles was not observed, suggesting very small size.
This is consistent with the conclusion obtained by the TEM
observation.
Au/ZrO -9.0 as the catalyst.
2
Fig. 4b demonstrates dependence of the conversion of
1600
o
o
methanol on reaction time at 120 C and 140 C. The conversion
increased with reaction time and a maximum conversion of 5.4%
1200
o
(
c)
d)
was reached at 120 C. However, the maximum conversion was
8
00
00
0
o
(
4
.0% at 140 C. The standard Gibbs free energy of the overall
3
3
4
(b)
a)
reaction is 26.8 kJ/mol. Therefore, the reaction is reversible and
equilibrium conversion was reached. It can also be known from
the figure that the equilibrium conversion at higher temperature is
lower. This is easy to understand because the reaction is
exothermic with standard reaction enthalpy of –10.5 kJ/mol.
We also characterized the catalysts used after the reaction at 120
(
2
0
40
60
80
2
Theta (degree)
3
3a
Fig. 2 The XRD patterns of the catalysts. (a) Au/CeO
Au/ZrO -9; (d) Au/ZrO -10.5.
2
; (b) Au/TiO
2
; (c)
2
2
o
o
C and 140 C for 7 hrs by TEM, and the images are presented in
Fig. 3 shows the XPS spectra of the catalysts. As can be
known from the figure, the Au 4f7/2 binding energies of the gold
in Au/ZrO -9.0 and Au/ZrO -10.5 are 84.2 eV and 84.1 eV,
the supporting information (Fig. S1), together with the TEM
image of the catalyst before used (Fig. 1e) for comparison. The
size of the Au particles did not change notably in the reaction, as
can be known from Fig. 1 and S1.
2
2
respectively. The slightly difference may be attributed to the
2
8
size effect. The binding energies of gold 4f7/2 in the Au/TiO
2
Fig. 4c shows the effect of total pressure of CO and H on
2
2
and Au/CeO are respectively 83.5 eV and 83.9 eV, which are
o
2
catalytic activity of the catalyst at 120 C. It can be seen that the
TOF increased with the total pressure. The main reason for this
phenomenon is that the concentrations CO and H increased
lower than the value of bulk metal (84.0 eV), implying the
electron transfer from supports to gold nanoparticles.
2
2
with pressure, which is favourable to the conversion of methanol.
The dependence of the TOF on reaction temperature is
illustrated in Table 1. As expected, the TOF increased with
increasing temperature. Our experiments showed that there was
no by-product in the reaction at all of the temperatures. Cu/ZnO
(a)
(b)
16,17
and Pd/Cu/ZnO were reported to be active for the reaction.
To
the best of our knowledge, these were the only catalysts reported
for the reaction without using basic additives. Comparing these
catalysts, the gold based catalysts have obvious advantages. The
75
80
85
90
95
75
80
85
90
95
Binding energy (eV)
Binding energy (eV)
o
(
d)
(c)
activity of the catalysts is very high. For example, at 120 C and
1
2
2 MPa, the TOF of the Au/ZrO -9.0 prepared in this work is 71
-1
16
h . At the similar condition, the TOFs of Pd/Cu/ZnO and
Cu/ZnO were 3.47 h (150 C, total pressure 6 MPa) and 2.38
h (150 C, total pressure 13 MPa ), respectively. In addition, the
catalysts of this work had very high selectivity and no
by-products were generated, while the catalysts Cu/ZnO and
Pd/Cu/ZnO were reported to produce some by-products, such as
1
7
-1
o
-1
o
75
80
85
90
95
75
80
85
90
95
Binding energy (eV)
Binding energy (eV)
Fig. 3 XPS spectra of (a) Au/CeO , (b) Au/TiO , (c) Au/ZrO -9,
2
2
2
and (d) Au/ZrO -10.5.
2
1
6,17
CO.
This indicates that the supported Au nanocatalysts have

Page 3 of 6
Green Chemistry
View Article Online
unique feature for the reaction. The main reason may be that Au
Hydrogen can be dissociated on low coordinated Au surface
DOI: 10.1039/C4GC01818D
sites and H are activated more efficiently when the Au particle
2
was smaller than 2 nm. Based on the results of this work and
the related researches reported in the literature, we propose a
possible mechanism for this reaction, as is shown in Scheme 1.
The CO was activated mainly by the interaction of its oxygen
atoms with catalysts. Formic acid is first formed on Au
particles. Then, esterification reaction between the formic acid
and methanol takes place. It is known that generation of formic
3
5
is much more efficient than Cu for the generation of formic acid,
which can react easily with methanol to form MF at the reaction
condition.
3
6
1
1
20
00
2
(a)
8
6
4
2
0
0
0
0
0
25
acid from hydrogenation of CO is a thermodynamically
2
2
a
unfavourable reaction. However, the formed MF moves away
from the surface of the catalyst. Therefore, the formic acid
intermediate can be yielded continuously until the equilibrium of
the reaction shown in Eq. (1) is reached. Thus, effective
Au/CeO
Au/TiO2 Au-ZrO
-10.5 Au-ZrO2-9
2
2
Catalysts
6
4
2
0
(
b)
o
activation of hydrogen and CO and desorption of the MF are all
(
120 C)
2
important for the reaction.
o
(
140 C)
0
2
4
6
8
10
-
1
Time (h
)
1
1
20
05
(
c)
9
7
6
0
5
0
Scheme 1 Possible mechanism for the formation of MF from
CO , hydrogen and methanol over Au catalyst.
2
1
2
14
16
18
20
Total Pressure (MPa)
Conclusion
Fig. 4 The influence of reaction conditions on reaction. (a) The
TOF values of the catalysts with different supports (P =8 MPa,
=16 MPa, 120 C, 80 mg catalysts, 3 hrs); (b) effect of reaction
time on the conversion of methanol (P =8 MPa, P =16 MPa, 80
mg Au/ZrO -9.0 at 120 C, 60 mg Au/ZrO -9.0 at 140 C); (c)
effect of the reaction pressure on the TOF values (120 C, 80 mg
Au/ZrO -9.0, 3 hrs).
The synthesis of MF from CO
by supported Au nanocatalysts has been carried for the first time.
All the catalysts, Au/ZrO , Au/CeO and Au/TiO have very high
2 2
, H , and methanol catalyzed
H2
o
P
T
2
2
2
H2
T
o
o
activity and selectivity for the reaction in wide temperature and
pressure ranges without any basic additives. The performances of
the catalysts depend considerably on the characters of the
supports and the size of the Au nanopartices. The TOF of the
2
2
o
2
Au/ZrO with an average Au size of 1.9 nm can be higher than
Table 1 Reaction results at different temperatures
2
-1
o
2
00 h at 140 C and 16 MPa. The catalytic reaction may include
Entry
P
H2
P
T
T
Time
Selectivity
TOF
mainly formation of formic acid intermediate and esterification of
formic acid and methanol.
a
o
-1
b
(
MPa)
(MPa)
16
( C)
60
(h)
3
(h )
1
2
3
4
8
8
8
8
8
8
8
8
>99.9%
>99.9%
>99.9%
>99.9%
>99.9%
>99.9%
>99.9%
>99.9%
4
Experimental details
16
80
3
14
16
100
120
140
160
180
200
3
40
Materials
16
3
102
204
309
430
534
.
.
2 2 4 2
ZrOCl 8H O (A. R. grade) and HAuCl 4H O (A. R. grade)
c
5
16
1
were purchased from Sinopharm Chemical Reagent Co. Ltd.
Ammonia aqueous solution (28%), urea, ammonia cerium nitrate,
DMF, n-butanol, and methanol were all A. R. grade and provided
by Beijing Chemical Reagent Company. The CO (>99.99%), H
d
6
16
1
e
7
16
1
2
2
f
8
16
1
(>99.99%), and N2 (>99.95%) were supplied by Beijing
Analytical Instrument Company. All the chemicals were used as
received without further purification.
a
b
Total pressure of hydrogen and CO
2
at reaction temperature, TOF values
c-f
denotes moles of MF per mole of gold per hour, reactions conducted using
6
2
0 mg, 40 mg, 30 mg, and 20 mg Au-ZrO -9.0 as the catalyst, respectively.
Catalyst preparation
It is interesting to study the reaction mechanism promoted by
The ZrO
literature.
2
support was prepared by the methods reported in
The Au/ZrO -9.0 was fabricated by
deposition-precipitation method with minor modification.
the Au catalysts. It has been reported that Au based catalysts have
satisfactory catalytic activity for the hydrogenation reactions of
2
7
2
2
7
34
unsaturated carbonyl compounds, alkynes and nitroaromatics.

Green Chemistry
Page 4 of 6
View Article Online
DOI: 10.1039/C4GC01818D
Briefly, 1.0 g ZrO
solution of 0.8 mmol/L, and then the pH value was adjusted to
.0 by addition of 0.25 mol/L ammonia solution drop by drop.
2 4
support was added to 60 mL HAuCl aqueous
Acknowledgement
9
After stirring at room temperature for 6 hours, the solid was
The authors are grateful to Ministry of Science and
Technology of China (2011CB808603), the National Natural
Science Foundation of China (21173239, 21303224, 21133009,
U1232203, 21021003), and the Chinese Academy of Sciences
(KJCX2.YW.H30) for the financial support.
filtrated and washed for 5 times using deionized water. The
o
sample was dried at 40 C under N flow for 12 hours. The
2
2 2
Au/ZrO -9.0 was obtained after reduction in H flow for 2 hours
o
at 250 C. The gold loading in the catalyst was 0.8 wt% as
determined by inductively coupled plasma atomic emission
spectroscopy (ICP-AES).
Note and references:
The procedure to prepare the Au/ZrO -10.5 was similar to
2
that used to fabricate Au/ZrO -9.0. The only difference was that
the pH value of the solution was adjusted to 10.5, instead of 9.0.
Beijing National Laboratory for Molecular Sciences, CAS Key
laboratory for colloid, interface and thermodynamics. Institute of
Chemistry, Chinese Academy of Sciences, Beijing, 100190,
China. E-mail: zhangzf@iccas.ac.cn; hanbx@iccas.ac.cn
Fax: (+86)10-62562821; Tel: (+86)10-62562821
2
2
The content of the gold in the Au/ZrO determined by ICP-AES
was 0.8 wt%.
Ceria support and Au/CeO catalyst was prepared by
2
6,37
2
deposition-precipitation method
with some modification.
Briefly, 1.0 g CeO was immersed in 100 mL HAuCl aqueous
1. (a) W. Wang, S. P. Wang, X. B. Ma and J. L. Gong, Chem.
Soc. Rev., 2011, 40, 3703-3727; (b) T. Sakakura, J. C. Choi
and H. Yasuda, Chem. Rev., 2007, 107, 2365-2387; (c) C.
Federsel, R. Jackstell and M. Beller, Angew. Chem. Int. Ed.,
2010, 49, 6254-6257; (d) M. Y. He, Y. H. Sun, and B. X. Han,
Angew. Chem. Int. Ed., 2013, 52, 9620-9633. (e) M.Aresta, A.
Dibenedetto and A. Angelini, Chem. Rev., 2014, 114,
1709-1742.
2
4
solution of 0.5 mmol/L, and the pH value of the solution was
adjusted to 9.0 by adding 0.02 mol/L NaOH solution. After
o
stirring at 70 C for 2 hours, the solid was filtrated and washed
o
for 5 times using deionized water. The sample was dried at 40 C
under N flow for 12 hours. The Au/CeO was obtained after
2
2
o
reduction in H flow for 2 hours at 250 C. The content of in the
2
2
Au/CeO was 0.78 wt% as determined by ICP-AES.
The Au/TiO2 catalyst with 1.0 wt% Au was supplied by
AUROlite Corporation.
2. (a) Z. F. Zhang, Y. Xie, W. J. Li, S. Q. Hu, J. L. Song, T. Jiang
and B. X. Han, Angew. Chem. Int. Ed., 2008, 47, 1127-1129;
(
b) T. Schaub and R. A. Paciello, Angew. Chem. Int. Ed., 2011,
Sample characterization
50, 7278-7282; (c) P. G. Jessop, T. Ikariya and R. Noyori,
Nature, 1994, 368, 231-233; (d) P. G. Jessop, Y. Hsiao, T.
Ikariya and R. Noyori, J. Am. Chem. Soc., 1996, 118, 344-355;
(e) R. Tanaka, M. Yamashita and K. Nozaki, J. Am. Chem.
Soc., 2009, 131, 14168-14169; (f) C. Ziebart, C. Federsel, P.
Anbarasan, R. Jackstell, W. Baumann, A. Spannenberg and M.
Beller, J. Am. Chem. Soc., 2012, 134, 20701-20704; (g) M. S.
Jeletic, M. T. Mock, A. M. Appel and J. C. Linehan, J. Am.
Chem. Soc., 2013, 135, 11533-11536; (h) S. Wesselbaum, U.
Hintermair and W. Leitner, Angew. Chem. Int. Ed., 2012, 51,
8585-8588.
The gold content in the catalysts was determined by ICP-AES
(
PROFILE SPEC, Leeman). The XRD characterization was
carried out on Rigaku D/max 2500 with nickel filtered Cu-Kα
λ=0.154 nm) operated at 40 kV and 20 mA. The XPS analysis
(
was performed using ESCALab 220I-XL equipment electron
spectrometer from VG Scientific using 300 W AlKα radiation
with a hemispherical energy analyzer. The binding energies were
calibrated with the C1s line at 284.8 eV from contaminated
carbon element. The TEM images of the catalysts were measured
on JEOL-2100F electron microscopy operated at 200 kV.
3. (a) F. Studt, I. Sharafutdinov, F. Abild-Pedersen, C. F. Elkjær, J.
S. Hummelshøj, S. Dahl, I. Chorkendorff, J. K. Nørskov,
Nature Chem., 2014, 6, 320-324; (b) S. Wesselbaum, T. vom
Stein, J. Klankermayer, W. Leitner, Angew. Chem. Int. Ed.,
2012, 51, 7499-7502; (c) J. Graciani, K. Mudiyanselage, F.
Xu, A. E. Baber, J. Evans, S. D. Senanayake, D.J. Stacchiola,
P. Liu, J. Hrbek, J. F. Sanz and J. A. Rodriguez, Science, 2014,
345, 546-550.
Reaction
The reaction was carried out in a Teflon-lined stainless steel
3
8
reactor of 16 mL, which was similar to that used previously. In
a typical experiment, 1.0 g methanol, desired amount of catalyst
was added into the reactor. The air in the reactor was replaced by
H . Then the reactor was placed in an air bath of desired
temperature. After stabilization for 1 hour, the H and CO gas
2 2
4. (a) Y. Xie, Z. F. Zhang, T. Jiang, J. L. He, B. X. Han, T. B.
Wu, K. L. Ding, Angew. Chem. Int. Ed., 2007, 46, 7255-7258;
(b) Q. W. Song, L. N. He, J. Q. Wang, H. Yasuda, T. Sakakura,
Green Chem., 2013, 15, 110-115; (c) K. R. Roshan, G. Mathai,
J. Kim, J. Tharun, G. A. Park and D. W. Park, Green Chem.,
2012, 14, 2933-2940; (d) M. R. Reithofer, Y. N. Sum and Y. G.
Zhang, Green Chem., 2013, 15, 2086-2090.
5. (a) P. G. Jessop, F. Joo and C. Tai, Coord. Chem. Rev., 2004,
248, 2425-2442; (b) J. L. Liu, C. K. Guo, Z. F. Zhang, T.
Jiang, H. Z. Liu, J. L. Song, H. L. Fan and B. X. Han, Chem.
Commun., 2010, 46, 5770-5772; (c) Q. Y. Bi, J. D. Lin, Y. M.
Liu, S. H. Xie, H. Y. He and Y. Cao, Chem. Commun., 2014,
2
were charged into the reactor and the stirrer was started with a
speed of 500 rpm. After the certain reaction time, the reactor was
placed in ice-water mixture and the gas was released slowly
through DMF cold trap to capture the MF in the gas flow. The
gas sample was collected in a gas bag. The liquid in the cold trap
was mixed with that in the reactor, and the mixture was analyzed
quantitatively by GC (Agilent 6820) equipped with a flame
ionization detector (FID) and a PEG-20M capillary column.
n-Butanol was used as external standard. The gas sample was
analyzed on GC with TCD detector.
5
0, 9138-9140.

Page 5 of 6
Green Chemistry
View Article Online
6
.
J. S. M.Campo, J. Rollin, S. Myung, Y. Chun, S.
Chandrayan,R. Patino, M. W. W. Adams and Y. H. P. Zhang,
Angew. Chem. Int. Ed., 2013, 52, 1-5.
33. (a) D. R. Lide, CRC Handbook of Chemistry & Physics (84th),
DOI: 10.1039/C4GC01818D
CRC press, 2003-2004; (b) C. L. Yaws, Yaws' Handbook of
Thermodynamic and Physical Properties of Chemical
Compounds, Knovel, 2005.
7
8
9
1
1
1
1
. A. Primo, T. Marino, A. Corma, R. Molinari and H. García, J.
Am. Chem. Soc., 2011, 133, 6930-6933.
34. T. Mitsudome and K. Kaneda, Green Chem., 2013, 15,
2636-2654.
35. A. Corma, M. Boronat, S. Gonzalezb and F. Illas, Chem.
Commun., 2007, 43, 3371-3373.
36. T. Fujitani, I. Nakamura, T. Akita, M. Okumura and M.
Haruta, Angew. Chem. Int. Ed., 2009, 48, 9515-9518.
37. N. Ta, M. L. Zhang, J. Li, H. J. Li, Y. Li and W. J. Shen, Catal.
Today, 2009, 148, 179-183.
38. J. Ma, B. X. Han, J. L. Song, J. Y. Hu, W. J. Lu, D. Z. Yang, Z.
F. Zhang, T. Jiang, M. Q. Hou, Green Chem., 2013, 15,
1485-1489.
. C. H. Han, X. Z. Yang, G. J. Gao, J. Wang, H. L. Lu, J. Liu, M.
Tong and X. Y. Liang, Green Chem., 2014, 16, 3603-3615.
. A. Wittstock, V. Zielasek, J. Biener, C. M. Friend and M.
Bäumer, Science, 2010, 327, 319-322.
0. P. G. Jessop, T. Ikariya and R. Noyori, Chem. Rev., 1995, 95,
259-272.
1. P. G. Jessop, Y. Hsiao, T. Ikariya and R. Noyori, J. Chem. Soc.,
Chem. Commun., 1995, 707-708.
2. O. Krocher, R. A. Koppel and A. Baiker, Chem.Commun.,
1
997, 453-454.
3. C. Federsel, A. Boddien, R. Jackstell, R. Jennerjahn, P. J.
Dyson, R. Scopelliti, G. Laurenczy and M. Beller, Angew.
Chem. Int. Ed., 2010, 49, 9777-9780.
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
4. M. Yadav, J. C. Linehan, A. J. Karkamkar, E. V. Eide and D. J.
Heldebrant, Inorg. Chem., 2014, 53, 9849-9854.
5. O. Krocher, R. A. Koppel, M. Froba and A. Baiker, J. Catal.,
1
998, 178, 284-298.
6. K. M. K. Yu, C. M. Y. Yeung and S. C. Tsang, J. Am. Chem.
Soc., 2007, 129, 6360-6361.
7. K. M. K. Yu and S. C. Tsang, Catal. Lett., 2011, 141,
2
59-265.
8. J. S. Chen, F. Xin, S. Y. Qin and X. H. Yin, Chem. Eng. J.,
013, 230, 506-512.
2
9. S. Y. Qin, F. Xin, Y. D. Liu, X. H. Yin and W. Ma, J. Colloid.
Interface. Sci., 2011, 356, 257-261.
0. J. S. Chen, S. Y. Qin, G. X. Song, T. Y. Xiang, F. Xin and X.
H. Yin, Dalton Trans., 2013, 42, 15133-15138.
1. M. Valden, X. Lai and D. W. Goodman, Science, 1998, 281,
1647-1650.
2. M. Boronat, P. Concepcion, A. Corma, S. Gonzalez, F. Illas
and P. Serna, J. Am. Chem. Soc., 2007, 129, 16230-16237.
3. A. Corma, P. Serna and H. Garcia, J. Am. Chem. Soc., 2007,
1
29, 6358-6359.
4. H. Sakurai, A. Ueda, T. Kobayashi and M. Haruta, Chem.
Commun., 1997, 33, 271-272.
5. D. Preti, C. Resta, S. Squarcialupi and G. Fachinetti, Angew.
Chem. Int. Ed., 2011, 50, 12551-12554.
6. N. Ta, J. Y. Liu, S. Chenna, P. A. Crozier, Y. Li, A. L. Chen
and W. J. Shen, J. Am. Chem. Soc., 2012, 134, 20585-20588.
7. Q. Y. Bi, X. L. Du, Y. M. Liu, Y. Cao, H. Y. He and K. N. Fan,
J. Am. Chem. Soc., 2012, 134, 8926-8933.
8. G. K. Wertheim and S. B. DiCenzo, Phys. Rev. B., 1988, 37,
844-847.
9. K. C. Petallidou, K. Polychronopoulou, S. Boghosian, S. G.
Rodriguez and A. M. Efstathiou, J. Phys. Chem. C, 2013, 117,
25467-25477.
3
3
3
0. K. P. Yu, W. Y. Yu, M. C. Kuo, Y. C. Liou and S. H. Chien,
Appl. Catal., B, 2008, 84, 112-118.
1. X. J. Liu, R. Wang, L. Y. Song, H. He, G. Z. Zhang, X. H. Zi
and W. G. Qiu, Catal. Commun., 2014, 46, 213-218.
2. (a) G. Postole, B. Chowdhury, B. Karmakar, K. Pinki, J.
Banerji and A. Auroux, J. Catal., 2010, 269, 110-121; (b) E. I.
R. Medgaarden, W. V. Knowles, T. Kim, M. S. Wong, W.
Zhou, C. J. Kiely and I. E. Wachs, J. Catal., 2008, 256,
108-125.

Green Chemistry
Page 6 of 6
View Article Online
DOI: 10.1039/C4GC01818D
TOC
Supported gold catalysts show excellent efficiency in methyl formate
synthesis from carbon dioxide, hydrogen and methanol.