Electronic Supplementary Material (ESI) for Catalysis Science & Technology.
This journal is © The Royal Society of Chemistry 2015
Electronic Supplementary Information for
Conversion of dihydroxyacetone to methyl lactate catalyzed
by highly active hierarchical Sn-USY at room temperature
Xiaomei Yanga, Lin Wua, Zhen Wanga, Jingjing Biana, Tianliang Lub, Lipeng Zhou*a,
Chen Chenc and Jie Xuc
a
College of Chemistry and Molecular Engineering, Zhengzhou University, 100 Kexue Road,
Zhengzhou 450001, P. R. China
b
School of Chemical Engineering and Energy, Zhengzhou University, 100 Kexue Road,
Zhengzhou 450001, P. R. China
c
State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian
Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian
116023, P. R. China
Contents:
1. Preparation of SnO2 and Sn-β (pp. 2-4)
2. Additional Results (pp. 5-10)
3. GC and HPLC Traces (p. 11)
1
1. Preparation of SnO2 and Sn-β
SnO2 was prepared by calcination of Sn(OH)4 at 640 oC for 4 h, which was
synthesized through precipitation of aqueous SnCl4 solution with NaOH. X-ray
diffraction (XRD) (Fig. S1) showed that the prepared SnO2 is in tetragonal structure.
110
3500
3000
PDF-770452
Tetragonal
101
Intensity (a.u.)
2500
211
2000
1500
1000
200
500
0
112
220
310 301
202
002
111
10
20
30
40
50
60
70
321
80
2 Theta (degree)
Fig. S1 XRD pattern of bulk SnO2.
Sn-β zeolite was synthesized by the hydrothermal method as following:
(1) Preparation of dealuminated β seeds
The dealuminated β seeds were prepared from H-β zeolite with Si/Al of 38.1
purchased from Nankai University Catalyst Co. (China). The parent H-β zeolite was
dealuminated with nitric acid (13 mol L–1, 20 mL g–1 zeolite) at 100 oC for 20 h. Then
the solid was separated by filtration and washed with deionized water until the filtrate
was neutral. Finally, the solid was dried at 100 oC to obtain dealuminated β seeds.
(2) Synthesis of Sn-β
The hydrothermal method described in references [2,3] was adopted to synthesize
Sn-β. 10.74 g tetraethyl ammonium hydroxide (TEAOH, 25% aqueous solution) was
2
mixed with 6.98 g TEOS in a plastic beaker. After stirring for 100 min, 0.74 g SnCl4
solution (0.14 g SnCl4·5H2O dissolved in 0.60 g H2O) was added dropwise and white
precipitate appeared. The mixture was continued to stir until 10.08 g H2O and EtOH
was evaporated. Then, 0.89 g HF (40% aqueous solution) was added, and the dense gel
was formed. Finally, the above dealuminated β seeds (0.083 g, ~4 wt% compared to the
theoretical zeolite amount) were suspended in demineralized water (0.58 g), sonicated
and added into the dense gel. The molar ratio of the resulting gel was as follows: 0.008
SnO2: 1 SiO2: 0.54 TEAOH: 0.54 HF: 7.5 H2O. The gel was mixed homogeneously
with a mortar, transferred to a closed Teflon vessel in a stainless steel autoclave, and
crystallized statically at 140 °C for 30 days. After crystallization, the autoclave was
cooled down to room temperature and the products were isolated by centrifugation. The
products were washed three times with demineralized water and dried at 100 °C
overnight. The dried powder was calcined in muffle furnace at 550 °C for 8 h to remove
carbonaceous residues. XRD patterns (Fig. S2) of the as-synthesized and calcined Sn-β
zeolites confirmed that the synthesized sample was in pure BEA structure [4]. The ratio
of nSi/nSn determined by X-ray fluorescence (XRF) is 177. The Ultraviolet-visible
(UV-vis) spectra of Sn-β and SnO2 were shown in Fig. S3. SnO2 showed a wide range
adsorption in the range from 200-500 nm. An adsorption band at 220 nm was observed
for Sn-β and no adsorption related to SnO2 was observed; it indicated that tin was
incorporated into the framework of BEA.
3
6000
Intensity (a.u.)
5000
(a)
4000
3000
2000
1000
0
10
20
30
40
50
40
50
2Theta (degree)
5000
(b)
Intensity (a.u.)
4000
3000
2000
1000
0
10
20
30
2Theta (degree)
Fig. S2 XRD patterns of (a) as-synthesized and (b) calcined Sn-β.
0.7
0.6
SnO2
Abs (a.u.)
0.5
0.4
0.3
0.2
Sn-
0.1
0.0
200
300
400
500
600
Wavelength (nm)
Fig. S3 UV-vis spectra of SnO2 and Sn-β.
4
Intensity (a.u.)
2. Additional Results
H-USY-8
H-USY-2
H-USY-0.5
H-USY-0.2
H-USY-parent
5
10
15
20
25
30
35
40
45
50
2Theta (degree)
Fig. S4 XRD patterns of the parent and acid-treated H-USY zeolites.
Fig. S5 TEM (a) and HRTEM (b) images of Sn-USY-8.
5
25 oC
3.0
y = -8.284*10-5x + 3.075
R2 = 0.999
k = 8.284*10-5 s-1
2.9
lnc
2.8
2.7
2.6
2.5
2.4
1000
2000
3000
4000
5000
6000
7000
8000
t (s)
3.05
30 oC
3.00
y = -1.356*10-4x + 3.115
R2 = 0.999
k = 1.356*10-4 s-1
2.95
2.90
lnc
2.85
2.80
2.75
2.70
2.65
2.60
500
1000
1500
2000
2500
3000
3500
4000
t (s)
35 oC
3.10
3.05
y = -2.309*10-4x + 3.126
R2 = 0.995
k = 2.309*10-4 s-1
3.00
2.95
lnc
2.90
2.85
2.80
2.75
2.70
200
400
600
800 1000 1200 1400 1600 1800 2000
t (s)
6
40 oC
3.0
y = -3.395*10-4x + 3.055
R2 = 0.995
k = 3.395*10-4 s-1
2.9
2.8
lnc
2.7
2.6
2.5
2.4
2.3
2.2
0
500
1000
1500
2000
2500
t (s)
-7.8
lnk = -8892/T + 20.45
R2 = 0.997
Ea = 74 kJ mol-1
-8.1
lnk
-8.4
-8.7
-9.0
-9.3
-9.6
3.18
3.21
3.24
3.27
3.30
3.33
3.36
-1
1000/T (K )
Fig. S6 Kinetic analysis of DHA conversion in methanol in the presence of Sn-USY-8
catalyst and Arrhenius plot (The X-axis is multiplied by 1000).
7
-3.8
-4.0
25 oC
-4.2
lnc
-4.4
-4.6
y = 3.475*10-4x - 5.805
R2 = 0.9998
k = 3.475*10-4 s-1
-4.8
-5.0
-5.2
1500 2000 2500 3000 3500 4000 4500 5000 5500
t (s)
-3.8
-3.9
35 oC
-4.0
lnc
-4.1
-4.2
y = 6.080*10-4x - 4.887
R2 = 0.990
k = 6.080*10-4 s-1
-4.3
-4.4
-4.5
-4.6
600
800
1000
1200
1400
1600
1800
t (s)
-3.0
40 oC
-3.2
-3.4
lnc
y = 7.268*10-4x - 4.318
R2 = 0.999
k = 7.268*10-4 s-1
-3.6
-3.8
-4.0
600
800
1000
1200
t (s)
8
1400
1600
1800
-7.2
-7.3
lnk = -4672/T + 7.727
R2 = 0.992
Ea = 39 kJ mol-1
-7.4
lnk
-7.5
-7.6
-7.7
-7.8
-7.9
-8.0
3.18 3.20 3.22 3.24 3.26 3.28 3.30 3.32 3.34 3.36
1000/T (K-1)
Fig. S7 Kinetic analysis of MLA formation in methanol in the presence of Sn-USY-8
catalyst and Arrhenius plot (The X-axis is multiplied by 1000).
-6.7
(a)
-6.8
-6.9
lnk = -6517/T + 14.00
Ea = 54 kJ/mol
R2 = 0.99
-7.0
lnk
-7.1
-7.2
-7.3
-7.4
-7.5
0.00318
0.00320
0.00322
0.00324
0.00326
0.00328
0.00330
1/T (K-1)
-7.0
(b)
lnk = -7585/T + 17.06
Ea = 63 kJ/mol
R2 = 0.96
-7.2
lnk
-7.4
-7.6
-7.8
-8.0
0.00318
0.00320
0.00322
0.00324
0.00326
0.00328
0.00330
1/T (K-1)
Fig. S8 Arrhenius plots for MLA formation over (a) Sn-Beta-P and (b) Sn-Beta-F in
methanol.
9
O
O
O
OH -H2O
HO
O
OCH3 Isomerization
+CH3OH
PA
DHA
OH
-H2O
CH3O
OCH3
OCH3
OCH3
1
+CH3OH
OH
CH3O
OH
OCH3
+CH3OH
O
+CH3OH
MLA
O
-H2O
OCH3
OCH3
OCH3
3
2
Addition products of PA with methanol
Scheme S1. Possible by-products of DHA conversion in methanol.
Table S1 Ratio of Lewis/Brønsted acid sites for Sn-USY
Sample
Ratio of Lewis/Brønsted acid
sitesa
a
Sn-USY-parent
2.0
Sn-USY-0.2
3.9
Sn-USY-0.5
11.9
Sn-USY-2
15.6
Sn-USY-8
20.4
The ratio is calculated using the method described in literature [5].
10
OCH3
3. GC and HPLC Traces
Solvent
Internal standard
CH3OH
CH3CHCOOCH3
OH
Fig. S9 GC trace of reaction mixture (Table 2, entry 2).
DHA
Fig. S10 HPLC trace of reaction mixture (Table 2, entry 2).
References
[1] C. Hammond, S. Conrad and I. Hermans, Angew. Chem. Int. Ed., 2012, 51, 1.
[2] A. Corma, L. T. Nemeth, M. Renz and S. Valencia, Nature, 2001, 412, 423.
[3] M. S. Holm, S. Saravanamurugan and E. Taarning, Science, 2010, 328, 602.
[4] R. Otomo, T. Yokoi, J. N. Kondo and T. Tatsumi, Appl. Catal. A, 2014, 470, 318.
[5] M. Guisnet, P. Ayrault, C. Coutanceau, M. F. Alvarez and J. Datkac, J. Chem. Soc.,
Faraday Trans., 1997, 93, 1661.
11