Catalytic production of 2,5-dimethylfuran from 5-hydroxymethylfurfural over Ni/Co3O4 catalyst

Article abstract of DOI:10.1016/j.catcom.2015.02.014

Ni/Co₃O₄, a non-precious metal catalyst was used for the first time in the catalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF). Under relatively mild conditions (130 °C, 1.0 MPa), as high as 76% yield of DMF was achieved. The addition of Ni not only prevented the formation of by-products, which happened due to the over-reduction of Co₃O₄ during hydrogenolysis, but also enhanced the reusability of Ni/Co₃O₄, and the catalyst could be reused for 6 times without loss of activity.

Full text of DOI:10.1016/j.catcom.2015.02.014

Catalytic production of 2,5-dimethylfuran from 5-hydroxymethylfurfural over
Ni/Co3O4 catalyst
Panpan Yang, Qiqi Cui, Yanhong Zu, Xiaohui Liu, Guanzhong Lu, Yanqin
Wang
PII:
DOI:
Reference:
S1566-7367(15)00073-4
doi: 10.1016/j.catcom.2015.02.014
CATCOM 4231
To appear in:
Catalysis Communications
Received date:
Revised date:
Accepted date:
24 November 2014
1 February 2015
11 February 2015
Please cite this article as: Panpan Yang, Qiqi Cui, Yanhong Zu, Xiaohui Liu,
Guanzhong Lu, Yanqin Wang, Catalytic production of 2,5-dimethylfuran from 5-
hydroxymethylfurfural over Ni/Co3O4 catalyst, Catalysis Communications (2015), doi:
10.1016/j.catcom.2015.02.014
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ACCEPTED MANUSCRIPT
Catalytic
production
of
2,5-dimethylfuran
from
5-hydroxymethylfurfural over Ni/Co3O4 catalyst
Panpan Yang, Qiqi Cui, Yanhong Zu, Xiaohui Liu, Guanzhong Lu, Yanqin Wang*
Shanghai Key Laboratory of Functional Materials Chemistry, Research Institute of Industrial
Catalysis, East China University of Science and Technology, Shanghai, 200237, China.
Tel:/Fax: (+86)-21-64253824
E-mail: wangyanqin@ecust.edu.cn
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Abstract
Ni/Co3O4, a non-precious metal catalyst was used for the first time in the catalytic
conversion of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF). Under relatively
mild conditions (130 oC, 1.0 MPa), as high as 76% yield of DMF was achieved. The addition
of Ni not only prevented the formation of by-products, which happened due to the
over-reduction of Co3O4 during hydrogenolysis, but also enhanced the reusability of
Ni/Co3O4, and the catalyst could be reused for 6 times without loss of activity.
Keywords: Ni/Co3O4; Hydrogenolysis; 5-hydroxymethylfurfural; 2,5-dimethylfuran
2

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1. Introduction
With the increasing demand of fossil fuels, and decreasing of petroleum resources,
economical and energy-efficient processes for the sustainable chemicals and products are
needed in the near future [1]. The potential of biomass to serve as renewable carbon sources
for transportation fuels and fine chemicals has attracted great interests [2,3].
5-hydroxymethylfurfural (HMF), a dehydration product of hexoses, has been considered as
an important platform molecular in the bio-based process, which can also be further
converted into different valuable chemicals, such as levulinic acid [4], γ-valerolactone [5],
2,5-furandicarboxylic [6] and 2,5-dimethylfuran [8]. Similar to ethanol, 2,5-dimethylfuran
(DMF) is considered as a sustainable and renewable liquid fuel. Noteworthily, the energy
density and boiling point of DMF (31.5 MJ/L, 92-94 C, respectively) are higher than those
of ethanol (23 MJ/L, 78 C, respectively). Paul Richards et al. [7] tested DMF as a biofuel in
a single-cylinder, spark-ignition, GDI (gasoline direct-injection) engine. In their report, DMF
needs no major modifications and adjustments to produce a similar engine performance and
emissions level compared with gasoline (the energy density is 35 MJ/L).
In 2007, Dumesic et al. [8] proposed a carbon-supported copper-ruthenium (CuRu/C)
catalyst with hydrochloric acid (HCl) and sodium chloride (NaCl) to produce DMF from
fructose. This biphasic catalytic system exhibited a 71% yield of DMF from 5 wt% HMF at
220 C under pressure of hydrogen (6.8 bar H2). Chidambaram and Bell [9] reported a
two-step approach for the conversion of glucose to DMF in ionic liquids with Pd/C catalyst at
120 C. Thananatthanachon and Rauchfuss [10] reported a Pd/C catalytic system for the
production of DMF from HMF using formic acid as a reagent. Recently, Zu et al. [11]
reported an excellent yield of DMF (93.4%) from HMF using Ru/ Co3O4 catalyst.
In all-above systems, precious metals were used, herein, we try to find some non-noble
metal catalysts to reduce the expense of catalysts. After screening of Co, Fe, Ni and Cu, we
found that Ni/Co3O4 was an efficient catalyst for the selective hydrogenolysis of HMF to
DMF and showed a good stability.
2. Experiments
2.1. Catalyst preparation
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The Ni/Co3O4 precursor was prepared by a typical hydrothermal method [12]. Typically,
0.03 mol Co(NO3)2·6H2O, 0.003 mol Ni(NO3)2·6H2O, 0.12 mol NH4F and 0.15 mol
CO(NH2)2 were dissolved in 70 ml deionized water under stirring. Then the solution was
transferred into a Teflon autoclave and the autoclave was maintained at 120 oC for 12 h. After
cooling down to room temperature, the products were washed several times with deionized
o
o
water, dried at 60 C in air for 12 h, and finally calcined in air at 400 C for 4 h to get the
corresponded Ni/Co3O4. Then the catalysts were reduced at 550 oC for 4 h with flowing H2 in
tube furnace with a ramp of 3 oCmin-1 before used as catalysts.
The Co3O4, NiO, Fe/Co3O4 and Fe/NiO catalysts were prepared in the same procedures
with Ni/Co3O4 as above.
2.2. Characterizations of the catalyst
X-ray diffraction patterns (XRD) were recorded with a Bruker diffractomer with Cu Kα
radiation in the 2θ range from 10 to 80. Transmission electron microscope (TEM) image
was obtained with JEM-1400. The temperature-programmed reduction (H2-TPR) experiment
was carried out in a gas mixture of 5 vol.% hydrogen in nitrogen at a flow rate of 40 cm3
o
o
min-1 and a heating rate of 10 C  min-1 from 25 to 750 C, and H2 uptake was measured
using a TCD detector.
2.3. Catalytic activity tests
A stainless steel autoclave (50 ml) equipped with a magnetic stirring bar was charged with
catalyst (0.100 g), HMF (0.252 g), THF (10 ml) and tridecane (0.245 ml, internal standard).
The reactor was pressurized with H2 several times to remove air and charged with the desired
H2 and heated to the desired temperature. After reaction, the autoclave was cooled down to
room temperature quickly and the solid catalyst was separated from the reaction mixture by
filtration. The products in the filtrate were analyzed by an Agilent7890 GC equipped with a
HP-5 column and a FID detector, and the further structural characteristics of the products
were identified by GC-MS.
3. Results and discussion
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3.1. Screening of the catalysts
{Table 1}
To find a better performance of transition metals in the conversion of HMF to DMF, a
series of catalysts were screened, such as Co3O4, NiO, Ni/Co3O4, Fe/Co3O4 and Fe/NiO,
which were all reduced at 550 C for 4 h before using. The catalytic performance was
summarized in Table 1. It could be seen that Co3O4 and Fe/Co3O4 had the same conversion of
HMF as Ni/Co3O4, but the selectivity to DMF were relatively lower, and the main
by-products were bis(hydroxymethyl)furan (BHMF) and 2-hydroxymethyl-5-methylfuran
(HMMF), meaning that the hydrogenation ability of Co3O4 and Fe/Co3O4 are lower than Ni/
Co3O4. Xu et al. [13] had reported that CoOx could effectively break the C-O bond and lead
to a high selectivity to pentanediol from furfural. Therefore, when NiO and Fe/NiO were used
as catalysts, low conversion of HMF and poor selectivity to DMF were obtained, meaning
both poor hydrogenation ability and the inability to cleavage C-O bond of NiO and Fe/NiO.
Finally, Ni/Co3O4 catalyst preformed best catalytic activities among the aboved catalysts in
this reaction with high yield of DMF (76%) because of good abilities of hydrogenation and
hydrogenolysis.
3.2.Selective conversion of HMF to DMF
3.2.1. Influence of reaction conditions on the catalytic performance
In order to understand the influence of reaction conditions, various reduction temperature,
reaction pressure and reaction temperature were tested. It could be seen from Table 2 that the
reduction temperature had an obvious influence on the yield of DMF, especially when the
catalyst was over-reduced at 650 C, a low yield of DMF was achieved. With the increase of
H2 pressure from 1.0-2.0 MPa, the yield of DMF decrease slightly, the ring open and ring
hydrogenation occurred at high pressure, while at low reaction pressure, the intermediate
product such as BHMF were detected because of the lack of hydrogen. Besides, at 130 C, 1
MPa, 76% yield was obtained. It can be seen that the catalyst could maintain a stable yield of
DMF with a range of temperatures and pressures (120-140 C, 1-1.5 Mpa).
{Table 2}
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3.2.2. Reaction pathways and intermediates
In order to better understand the pathway of this reaction, we explored the intermediate
products distribution at different reaction times. Fig. 1 shows the changes of different
products during the reaction. It could be seen that HMF was already totally converted in the
first three hours. Both BHMF and HMMF were generated as main intermediate products,
only a little amount of DMF was detected. After that, the yield of DMF gradually increased
with time going by. Besides, 5-methylfurfural (5-MF) was always detected, but decreased
with time going by as shown in Fig.1B. Interestingly,
a
main byproduct
(2,2’-(1,2-ethanediyl)bis [5-methylfurna]) was detected at t=3 hours, and increased gradually.
Harwood et al. [14] obtained (2,2’-(1,2-ethanediyl)bis [5-methylfurna]) with 5-methylfurfural
(5-MF) as substrate over Pd/BaSO4. To find the possible pathway of this byproduct in our
catalytic system, we used 5-MF as substrate (Fig.2) and found 2,2’-(1,2-ethanediyl)bis
[5-methylfurna] was generated at t=0.5 h, so this by-product may came from 5-MF at the
beginning of this reaction.
Based on the above experiments, we proposed a main reaction pathway in Scheme 1. HMF
was first hydrogenated to BHMF and then deoxygenated to HMMF and finally deoxygenated
to DMF. Only a little amount of 5-MF was detected, part of them were hydrogenated to
HMMF, the others converted into the main by-products. The definite mechanism and
elimination of this by-product are still under study.
{Figure 1}
{Figure 2}
{Scheme 1}
3.3. Characterization of the catalyst
XRD patterns of Ni/Co3O4 (Fig. 3) gave diffraction peaks belong to Co3O4. No diffraction
peaks of NiO were observed, which indicated that Ni was highly dispersed on Co3O4. After
reduction at 550 oC, the peaks corresponding to Co3O4 disappeared, and the diffraction peaks
of Co0 and Ni0 were observed.
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{Figure 3}
The H2-TPR profiles of two catalysts are shown in Fig.4. For the Co3O4 sample, two H2
o
consumption peaks could be found. The first peak at 380 C was due to the reduction of
o
Co3O4 to CoO, the second peak at about 457 C was due to the reduction of CoO to the Co0
[15]. With regard to the Ni/Co3O4 sample, the low-temperature reduction peak was observed
o
o
at 326 C, and the high-temperature reduction peak was at 424 C, indicating that both
low-temperature and high-temperature peaks shifted to lower temperature with the addition
of Ni.
{Figure 4}
3.4. Circles of the catalyst
The stability and recyclability of the catalyst is of great importance for practical
application in industrial processes. So the test of Ni/Co3O4 was evaluated through 6 reaction
cycles. The recycling experiments involved filtration of catalysts from THF, washed with
THF for several times and dried in vacuum oven to prevent from oxidation. From the above
results, it showed that Ni/Co3O4 (Fig.5. left) performed almost the same reactivity after being
used for six times. The XRD patterns of fresh and used catalysts were almost no difference,
which meant the catalyst was stable in the process of conversion of HMF to DMF. When
Co3O4 was used after six times (Fig.5. right), the yield of DMF decreased from 70% to 51%.
We speculated that the decrease in the catalytic activity was probably caused by the
overreduction of Co3O4 during the recycling process, and this led the production of
by-products, such as HMMF and 2,2’-(1,2-ethanediyl)bis [5-methylfurna].
{Figure 5}
4. Conclusions
In summary, Ni/Co3O4 catalyst was prepared with hydrothermal method for the
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conversion of HMF to DMF. Under the mild reaction conditions, this catalyst exhibited a
good activity and could be reused for 6 times without loss of activity. Based on our group’s
former work, CoOx works for the absorption of hydrogenation product and both of CoOx and
Ni could break the C-O bond. Addition of Ni improves the hydrogenation ability and
selectivity to DMF. Furthermore, transition metals have good hydrogenation property which
makes them as potential catalysts for the hydrogenolysis of biomass-derived molecules.
Acknowledgements
This project was supported financially by the NSFC of China (No. 21101063 and 21273071),
the science and technology commission of shanghai municipality (13520711400,
13JC1401902, 10dz2220500) and the Fundamental Research Funds for the Central
Universities, China.
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238-242.
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[8] Y. Roman-Leshkov, C.J. Barrett, Z.Y. Liu, J.A. Dumesic, Nature 447 (2007)
982-985.
[9] M. Chidambaram, A.T. Bell, Green Chem. 12 (2010) 1253-1262.
[10] T. Thananatthanachon, T.B. Rauchfuss, Angew. Chem. Int. Ed. 49 (2010)
6616-6618.
[11] Y.H. Zu, P.P. Yang, J.J. Wang, X.H. Liu, J.W. Ren, G.Z. Lu, Y.Q. Wang. Appl.
Catal. B Environ. 146 (2014) 244-248.
[12] J.Q. Sun, Y.P. Li, X.J. Liu, Q. Yang, J.F. Liu, Chem. Commun. 48 (2012)
3379-3381.
[13] W.J. Xu, H.F. Wang, X.H. Liu, J.W. Ren, Y.Q. Wang, G.Z. Lu, Chem. Commun.
47 (2011) 3924-3926.
[14] L.M. Harwood, G. Jones, J. Pickard, R.M. Thomas, D. Watkin, Tetrahedron Lett.
29 (1988) 5825-5828.
[15] H.Y. Lin, Y.W. Chen, Materials Chemistry and physics 85 (2004) 171-175.
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Figure Captions:
Fig. 1. Yield of DMF with Ni/Co3O4 catalyst versus reaction time. (Reaction
conditions: catalyst, 0.1 g; HMF, 0.25 g; THF, 10 ml; reaction temperature, 130 oC; H2
pressure, 1 MPa.).
Fig. 2. Plots of selectivities to various compounds for the hydrogenation of 5-MF over
Ni/Co3O4 catalyst versus reaction time. (Reaction conditions: catalyst, 0.1 g; 5-MF,
0.25 g; THF, 10 ml; reaction temperature, 130 oC; H2 pressure, 1 MPa.)
Fig. 3. XRD patterns of Ni/Co3O4 after calcination (a) and reduction (b).
Fig. 4. Temperature programmed reduction (TPR) of Ni/Co3O4 and Co3O4 catalyst.
Fig. 5. The recyclability of Ni/Co3O4 (Left) and Co3O4 (right) catalysts in the
conversion of HMF. (Reaction conditions: catalyst, 0.1 g; HMF, 0.25 g; THF, 10 mL;
reaction temperature, 130 oC; H2 pressure, 1 MPa; reaction time, 24 h.)
Scheme 1 Possible reaction pathway for the conversion of HMF to DMF.
Table 1 Screening of metallic oxide in the catalytic reduction of HMF.
Table 2 The influence of reduction temperature, reaction pressure and temperature on
the performance of Ni/Co3O4 catalyst. Reaction conditions: catalyst, 0.1 g; HMF, 0.25
g; THF, 10 ml.
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A
BHMF
HMMF
40
30
20
10
0
O
O
DMF
3
6
9
Time (h)
2.0
1.5
1.0
0.5
0.0
5-MF
B
0.5
1.0
1.5
2.0
2.5
Time (h)
Fig.1.
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DMF
HMMF
5-MF
60
50
40
30
20
10
0
by-product
0.5
1.0
1.5
2.0
Time(h)
Fig.2.
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●
● Co3O4
◆ Co
■ Ni
●
●
●
●
●
●
a
b
●
●
(■)
◆
◆
◆
■
10
20
30
40
50
60
70
80
2 Theta (degree)
Fig. 3.
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Ni/Co3O4
Co3O4
700
100
200
300
400
500
600
800
Temperature (oC)
Fig. 4.
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120
100
80
60
40
20
0
Conv. (HMF)
Yield (DMF)
1
2
3
4
5
6
Run numbers
120
Conv. (HMF)
Yield (DMF)
100
80
60
40
20
0
1
2
5
6
Run3Numb4ers
Fig. 5
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O
+H2
O
O
O
+H2
-H2O
OH
O
O
MF
+H2
OH
OH
OH
+H2
HMF
O
O
O
+H2
+H2
-H2O
-H2O
HMMF
BHMF
DMF
Scheme 1
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Table 1 Screening of metallic oxide in the catalytic reduction of HMF.
Catalyst
T(oC)
P(MPa)
Conv.(
YDMF(%
s
%)
)
Co3O4
130
130
130
130
130
1.0
1.0
1.0
1.0
1.0
>99
70.1
NiO
73.5
>99
>99
82.4
7.3
Ni/Co3O4
Fe/Co3O4
Fe/NiO
76.0
60.0
2.6
Reaction conditions: catalyst, 0.1g; HMF, 0.25g; THF, 10ml; 24h.
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Table 2 The influence of reduction temperature, reaction pressure and temperature on
the performance of Ni/Co3O4 catalyst. Reaction conditions: catalyst, 0.1g; HMF, 0.25g;
THF, 10 ml.
Entry
Reduction Temp.
Pressure
/MPa
Reaction
Temp.
/ C
Conv.
/%
YDMF
/%
/ C
1
2
3
4
5
6
6
7
8
450
550
650
550
550
550
550
550
550
1.0
1.0
1.0
1.0
1.0
0.7
1.2
1.5
2.0
130
>99
>99
>99
>99
>99
>99
>99
>99
>99
71.2
76.0
51.4
75.0
74.7
57.1
75.2
74.2
71.1
130
130
120
140
130
130
130
130
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Catalytic
production
of
2,5-dimethylfuran
from
5-hydroxymethylfurfural over Ni/Co3O4 catalyst
Panpan Yang, Qiqi Cui, Yanhong Zu, Xiaohui Liu, Guanzhong Lu, Yanqin Wang*
Shanghai Key Laboratory of Functional Materials Chemistry, Research Institute of
Industrial Catalysis, East China University of Science and Technology, Shanghai,
200237, China.
* Corresponding author.
Fax: 0086-21-64253824
Tel: 0086-21-64253824
E-mail addresses: wangyanqin@ecust.edu.cn
A non-precious metal catalyst, Ni/Co3O4 prepared with hydrothermal method was
used for the first time in the catalytic conversion of 5-hydroxymethylfurfural (HMF)
to 2,5-dimethylfuran (DMF) and exhibited excellent catalytic performance.
Graphical abstract
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Highlights:
· A non-precious metal catalyst Ni/Co3O4 was prepared in a simple
hydrothermal method.
· As high as 76% DMF yield was achieved under relatively mild
conditions.
· The catalyst can be recycled for 6 times without a significant loss of
activity.
21