Supplementary Information
Construction of porous cationic frameworks by crosslinking polyhedral
oligomeric silsesquioxane units with N-heterocyclic linkers
Guojian Chen†, Yu Zhou†, Xiaochen Wang, Jing Li, Shuang Xue, Yangqing Liu, Qian Wang & Jun
Wang*
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and
Chemical Engineering, Nanjing Tech University, Nanjing 210009, China.
†
These authors contributed equally to this work.
* Correspondence and requests for materials should be addressed to J.W.
(email: junwang@njtech.edu.cn).
S1
Supplementary Experimental Section
Synthesis of octakis(3-chloropropyl)silsesquioxane ClPrPOSS. ClPrPOSS was synthesized by
previously reported method with a slight modification. As shown in Supplementary Fig. S1, a
solution of 400 mL of dry methanol and 15 mL of concentrated hydrochloric acid was placed in a
round-bottomed flask, and then (3-chloropropyl)trimethoxysilane (20 mL) was slowly added into
the solution. The reaction mixture within the closely sealed flask, was maintained at temperature of
40oC for two weeks until a mass of white crystalline precipitate appeared. The solution was filtered
and the crystals were collected, washed several times with methanol, and dried under vacuum. The
final product was obtained in 32% yield (4.5 g). Spectroscopic data of ClPrPOSS are as follows (see
Supplementary Figs. S6 and 7). 1H NMR (500 MHz, CDCl3) δ 0.79 (t, 16H, SiCH2), 1.86 (qui, 16H,
CH2), 3.54 ppm (t, 16H, CH2Cl). 13C NMR (125 MHz, CDCl3) δ 8.84 (SiCH2), 25.75 (CH2), 46.50
ppm (CH2Cl).
Supplementary Figures and Tables
Supplementary Figure S1. Synthesis of octakis(3-chloropropyl)silsesquioxane ClPrPOSS.
S2
1
Supplementary Figure S2. 1H NMR of ClMePOSS.
1
Supplementary Figure S3. 13C NMR of ClMePOSS.
S3
3
T
-78.3
a
29
Si NMR
2
T
-69.0
0
-50
-100
Chemical shift (ppm)
-150
T3γ
b
Tn peaks
T2α
T2β
T3α
T3β
T3γ
T2α
T3α
T2β
Supplementary Figure S4. (a)
ppm
-68.7
-70.5
-76.2
-77.9
-78.3
29
T3β
Si MAS NMR spectra of ClMePOSS and (b) its fitting with
multiple peaks. A small signal at –69.0 ppm and the main signal at –78.3 ppm for the as-synthesized
ClMePOSS are assigned to its T2, T3 structures with a relatively high T3 / (T2+T3) ratio 0.901,
indicating that the new POSS monomer possesses a high percentage (ca. 90%) of T3 structure
silicons. Fitting the spectrum with multiple peaks reveals three possible T3α, T3β, T3γ silicon peaks at
S4
-76.2, -77.9, -78.3 ppm, respectively, attributable to the T3 silicons originated from the minor
incompletely condensed POSS units (T2α, T2β silicons) and major completely condensed cubic
POSS units (Macromolecules 38, 5088-5097 (2005)). The splitting of the T3 signal can be assigned
to existence of minor T2 silicons in ClMePOSS that disturb the local environments of T3 silicons.
Supplementary Figure S5. MALDI-TOF MS spectra of ClMePOSS (DHB matrix, THF as the
solvent). The MALDI-TOF MS result gave one sharp strong peak at m/z=813.48, index of T3 cubic
POSS unit (Mw=812.48 g mol-1). Two very small peaks were observed at m/z=735.70 and 826.64
attributable to incompletely condensed POSS units of trisilanol R7Si7O9(OH)3 POSS-triol and
R8Si8O11(OH)2 POSS-diol respectively (J. Organomet. Chem. 693, 1301-1308 (2008)). The above
results indicated that the major POSS units were cubic structure, well in accord with the analysis
result of 29Si MAS NMR spectrum of ClMePOSS.
S5
3
1
2
Supplementary Figure S6. 1H NMR of ClPrPOSS.
3
Supplementary Figure S7. 13C NMR of ClPrPOSS.
S6
2
1
Supplementary Figure S8. Schematic formation process of Si–C–N bonds, Tn and Qn silicons units
due to the partial cleavage of Si–C bonds during the synthesis of POSS-based porous cationic
framework PCIF-1.
Supplementary Fig. S8 schematically depicts the formation process of Si–C–N bonds, Tn and Qn
silicons units due to the partial cleavage of Si–C bonds during the synthesis of POSS-based porous
cationic framework PCIF-1. The Q4-structured POSS units were resulted from the self-condensation
of silanols from the formed Q3 units under the weak basic environment. Minor Q2 structure of
silicons may be derived from the cleavage of Si–C in original T2 units or the decomposition of
siloxane bond in Q3 units (not shown in Supplementary Figure 8). Finally, the attack of nucleophilic
rigid organic linker and the distortion of POSS cages accelerate the formation of Si–C–N bonds and
partial cleavage Si–C bonds to obtain Tn and Qn silicons units combined POSS-based porous
cationic framework PCIF-1.
Supplementary Figure S9. Various N-heterocyclic compounds used for synthesizing water-soluble
POSS-ILs.
S7
0.2
5.40 nm
PCIF-1(M8)
5.40 nm
PCIF-1(M6)
0.1
0.0
0.1
3
-1
dVp/ddp(cm g )
0.2
0.0
0.8
3.71 nm
PCIF-1(M4)
0.4
0.0
2.40 nm
3.71 nm
0.02
PCIF-1(M2)
0.00
1
10
Pore diameter dp (nm)
100
Supplementary Figure S10. BJH pore size distributions of PCIF-1 series of PCIF-1(M2),
PCIF-1(M4), PCIF-1(M6), and PCIF-1(M8).
S8
3
-1
Volume Adsorption (cm g )
a 200
150
100
50
0
0.0
0.2
0.4
0.6
0.8
1.0
Relative pressure (P/P0)
b 0.005
3.71 nm
0.003
3
-1
dVp/ddp(cm g )
0.004
0.002
0.001
0.000
1
10
Pore diameter dp (nm)
100
Supplementary Figure S11. (a) N2 adsorption-desorption isotherms and (b) BJH pore size
distributions of the PCIF-1 network, which was prepared in the toluene solution.
S9
a 400
b 0.06
72 h
0.03
72 h
2.18 nm
4.35 nm
48 h
2.18 nm
4.66 nm
36 h
2.02 nm
24 h
48 h
3
300
3
-1
Volume adsorption (cm g )
0
-1
-1
Differential Pore Volume dVp (cm nm g )
200
2.20 nm
5.17 nm
0
36 h
200
0
24 h
200
0
12 h
200
0
0.0
0.8
0.6
0.4
0.2
Relative pressure (P/P0)
1.0
0.00
0.08
0.00
0.08
0.00
0.1
4.00 nm
0.0
1.88 nm
2.35 nm
4.00 nm
0.1
0.0
1
10
Pore diameter dp (nm)
12 h
100
Supplementary Figure S12. (a) N2 adsorption-desorption isotherms and (b) NLDFT pore size
distributions of PCIF-1(M4) using different reaction time.
S10
b 0.08
o
120 C
-1
400
Differential Pore Volume dVp (cm nm g )
a
0.04
120 C
2.33 nm
6.32 nm
110 C
o
-1
200
2.20 nm
4.68 nm
o
3
110 C
3
-1
Volume adsorption (cm g )
0
600
300
0
400
o
100 C
200
0
400
o
90 C
200
0
200
o
80 C
100
0
0.0
0.00
0.08
0.04
0.00
0.10
2.04 nm
0.05
o
o
100 C
4.12 nm
0.00
0.10
2.04 nm
o
90 C
3.90 nm
0.05
0.00
0.04
1.85 nm
o
80 C
0.02
0.2
0.4
0.6
0.8
Relative pressure (P/P0)
1.0
0.00
1
10
Pore diameter dp (nm)
100
Supplementary Figure S13. (a) N2 adsorption-desorption isotherms and (b) NLDFT pore size
distributions of PCIF-1(M4) series at different reaction temperature.
S11
b
20 mL
400
15 mL
3
3
-1
Volume adsorption (cm g )
-1
-1
200
0
400
200
0.00
0.06
2.20 nm
400
2.18 nm
0
400
0.00
5 mL
2.05 nm
0.08
200
0.4
0.6
0.8
1.0
Relative pressure (P/P0)
5 mL
2.50 nm
4.35 nm
0.04
0.2
10 mL
5.86 nm
0.04
200
15 mL
4.35 nm
0.00
10 mL
20 mL
4.18 nm
0.04
0.03
0
0
0.0
2.20 nm
0.08
Differential Pore Volume dVp (cm nm g )
a
0.00
1
10
Pore diameter dp (nm)
100
Supplementary Figure S14. (a) N2 adsorption-desorption isotherms and (b) NLDFT pore size
distributions of PCIF-1(M4) using different amount of solvent THF.
S12
d 3.5
1.0
SBET
Vtotal
2
-1
3
-1
SBET (m g )
0.8
Vtotal (cm g )
900
800
0.6
700
600
Average pore size Dav (nm)
a 1000
48
2.5
2.0
0.4
24
3.0
12
72
24
36
Reaction time (h)
1.0
1000
Vtotal
800
0.6
600
3
-1
Vtotal (cm g )
2
-1
SBET (m g )
0.8
0.4
400
90
100
110
3.5
3.0
2.5
80
120
1.0
3
2
0.6
800
0.4
15
20
0.2
Average pore size Dav (nm)
-1
Vtotal (cm g )
-1
SBET (m g )
0.8
900
10
110
120
f 3.5
SBET
5
100
Temperature ( C)
Vtotal
700
90
o
o
Temperature ( C)
c 1000
72
2.0
0.2
80
60
e
SBET
Average pore size Dav (nm)
b
48
Reaction time (h)
3.0
2.5
2.0
5
10
15
20
Amount of solvent THF (mL)
Amount of solvent THF (mL)
Supplementary Figure S15. Influences of reaction parameters (reaction time, temperature and
amount of solvent THF) on the surface area (SBET), pore volume (Vtotal) and average pore size (Dav)
of PCIF-1(M4) samples.
It was apparently that the surface area, pore volume and average pore size first increased with the
reaction time, reaching the maximum value at 48 h, and then decreased with longer reaction time.
Similar variations were observed by surveying the influence of reaction temperature and the solvent
amount. The results indicate that the surface area, pore volume and average pore size of PCIF
materials can be regularly adjusted by those factors, while keeping similar type IV N2 sorption
S13
isotherms and pore size distributions with sharp peaks centered at ca. 2 nm (Supplementary Figs.
3
-1
Volume adsorption (cm g )
0
20
PCIF-3
0
20
PCIF-4
0
PCIF-5
200
0
PCIF-6
200
0
b
0.04
-1
100
0.02
-1
PCIF-2
0.00
3
a 200
Differential Pore Volume dVp (cm nm g )
S12-S14).
0.002
0.2
0.4
0.6
0.8
1.0
Relative pressure (P/P0)
PCIF-2
3.25 nm
2.35 nm
5.06 nm
0.000
0.002
2.52 nm
5.78 nm
0.001
PCIF-3
PCIF-4
0.000
0.04
2.01 nm
3.93 nm
PCIF-5
0.00
0.04
2.16 nm
PCIF-6
2.01 nm
PCIF-7
0.02
0.00
0.01
PCIF-7
50
0
0.0
1.90 nm
0.00
1
10
Pore diameter dp (nm)
Supplementary Figure S16. (a) N2 adsorption-desorption isotherms and (b) NLDFT pore size
distributions of PCIF-n series samples with n corresponding to various organic linkers (2: bpe, 3:
bpea, 4: bppa, 5: bim, 6: tmeda, 7: dabco).
S14
The stability of PCIF-1(M4) in various solvents.
PCIF-1(M4) was selected as a typical sample to investigate its stability in various solvents. The
sample was soaked in water, typical organic solvents (CH3OH, CHCl3, DMF, and DMSO) for 24 h
at the room temperature, and then the samples were recovered by the filtration, washing and drying.
All the dry samples were fully characterized by N2 sorption, SEM, XRD and FT-IR. N2 sorption
experiment and textural parameters of the recovered PCIF-1(M4) samples (Supplementary Fig. S17,
Supplementary Table S4) demonstrate that the porous structures of PCIF-1(M4) are well retained in
spite of the slight changes of BET surface areas, total pore volumes and pore sizes. The above
results are further confirmed by the no noticeable change of morphologies and crystalline states
(Supplementary Figs. S18 and S19). Besides, no noticeable spectral change were observed in FT-IR
spectra (Supplementary Fig. S20), indicating their excellent structural stability in water and organic
solvents. In brief, the PCIF materials possess well stability in water and common organic solvents.
b 0.08
0
400
-1
*CH3OH
3
200
0
400
200
*CHCl3
0
400
200
*DMF
0
400
200
0
0.0
*DMSO
0.2
0.4
0.6
0.8
Relative pressure (P/P0)
1.0
-1
-1
PCIF-1(M4)*H2O
0.04
0.00
3
200
Volume Adsorption (cm g )
2.35 nm
PCIF-1(M4)
4.28 nm
*H2O
8.80 nm
400
Differential Pore Volume dVp (cm nm g )
a
0.04
2.35 nm
4.30 nm
8.68 nm
0.00
*CH3OH
2.34 nm
4.28 nm
9.50 nm
0.04
0.00
*CHCl3
2.05 nm
0.04
*DMF
4.30 nm
8.03 nm
0.00
0.10
2.05 nm
0.05
*DMSO
5.46 nm
0.00
1
10
Pore diameter dp (nm)
100
Supplementary Figure S17. (a) N2 adsorption-desorption isotherms and (b) NLDFT pore size
distributions of PCIF-1(M4) after soaked in H2O or various organic solvents (CH3OH, CHCl3, DMF,
and DMSO). The asterisk (*) before solvents represents the sample of PCIF-1(M4) treated in this
solvent.
S15
Supplementary Figure S18. (a) SEM images of PCIF-1(M4) after treated in (a, b) H2O, (c, d)
CH3OH, (e, f) CHCl3, (g, h) DMF, and (i, j) DMSO.
S16
o
o
23.40 ,0.38 nm
o
23.36 , 0.38 nm
o
23.28 , 0.38 nm
5.75 , 1.54 nm
PCIF-1(M4)
*DMSO
o
Intensity (a.u.)
5.64 , 1.56 nm
*DMF
o
5.81 , 1.52 nm
*CHCl3
o
23.38 , 0.38 nm
o
5.79 , 1.53 nm
*CH3OH
o
23.45 ,0.38 nm
o
5.81 ,1.52 nm
10
*H2O
20
30
2 Theta (degrees)
40
50
Supplementary Figure S19. XRD patterns of PCIF-1(M4) after treated in H2O or various organic
solvents (CH3OH, CHCl3, DMF, and DMSO). The asterisk (*) before solvents represents the sample
of PCIF-1(M4) soaked in this solvent.
PCIF-1(M4)
Transmittance (%)
* H2O
* CH3OH
* CHCl3
* DMF
* DMSO
2943 2854
814
1633 1399
949
1204
1079
4000 3500 3000 2500 2000 1500 1000
-1
Wavenumbers (cm )
500
Supplementary Figure S20. FT-IR spectra of PCIF-1(M4) and the ones after treated in H2O or
various organic solvents (CH3OH, CHCl3, DMF, and DMSO). The asterisk (*) before solvents
represents the sample of PCIF-1(M4) soaked in this solvent.
S17
1.0
-1
CO2 adsorpation (mmol g )
a
0.8
b
0.6
c
0.4
d
0.2
0.0
0.0
0.2
0.4
0.6
Pressure (bar)
0.8
1.0
Supplementary Figure S21. CO2 adsorption isotherms of PCIF-1 series (a) PCIF-1(M4) at 273 K,
1.0 bar; (b) PCIF-1(M4), (c) PCIF-1(M6), and (d) PCIF-1(M8) at 298 K, 1.0 bar.
Supplementary Figure S22. Schematic image for anion exchange process of very bulky PMoV
anions to replace the small Cl ions. Referring to the book of “Ion Exchange Materials: Properties
and Applications” by Andrei A. Zagorodni.
S18
100
PCIF-1(M8)
PMoV@PCIF-1
Loss of weight (wt %)
90
80
11.0 wt%
70
60
50
100
200
300
400
500
600
700
o
Temperature ( C)
Supplementary Figure S23. TGA curves of PCIF-1(M8) and PMoV@PCIF-1 under air
atmosphere.
Cl: 1.81 wt%
Supplementary Figure S24. Energy-dispersive X-ray spectrometry (EDS) spectrum and element
distributions of PMoV@PCIF-1.
S19
a
b C1s
c O1s
Mo3p1/2
Mo3p3/2
P2p
Si2p
Cl2p
400
200
Binding Energy (eV)
0
295
290
e Cl2p
102.9
Mo3d
f
100
95
210
205
h
Mo3d5/2
200
195
Binding Energy (eV)
Mo3p N1s
235
Intensity (a.u.)
Intensity (a.u.)
Mo3d3/2
235.4
230
Binding Energy (eV)
225
420
190
133.4
405
400
Binding Energy (eV)
132.8
135
130
125
395
V2p
V2p3/2
517.0
N1s
401.5
410
525
P2p
140
i
Mo3p1/2
415.6
415
530
Binding Energy (eV)
Mo3p3/2
398.2
232.3
240
535
Intensity (a.u.)
C-Cl
201.5
Intensity (a.u)
105
540
Binding Energy (eV)
-
Binding Energy (eV)
g
280
atomic concentration Cl
200.0
1.18 at%
Intensity (a.u.)
110
285
Binding Energy (eV)
Intensity (a.u.)
d Si2p
V-O
530.1
Intensity (a.u.)
C1s
V2p
600
Intensity (a.u.)
Intensity (a.u.)
Mo3d
N1s
800
•Si-O
534.2
285.7 285.4
O1s
390
516.3
V2p1/2
524.3 523.4
525
515.3
520
515
510
Binding Energy (eV)
Supplementary Figure S25. High resolution XPS spectra of PMoV@PCIF-1. (a) Survey, (b) C1s,
(c) O1s, (d) Si2p, (e) Cl2p, (f) P2p, (g) Mo3d, (h) Mo3p and N1s, and (i) V2p.
S20
a 450
3
-1
Volume adsorption (cm g )
PCIF-1(M8)
PMoV@PCIF-1
300
150
0
0.0
0.2
0.4
0.6
0.8
1.0
Relative pressure (P/P0)
b 0.20
PCIF-1(M8)
PMoV@PCIF-1
5.4 nm
3.7 nm
3
-1
dVp/ddp (cm g )
0.15
0.10
0.05
0.00
1
10
Pore diameter dp (nm)
100
Supplementary Figure S26. (a) N2 adsorption-desorption isotherms and (b) BJH pore size
distributions of PCIF-1(M8) and PMoV@PCIF-1.
S21
Supplementary Table S1. Textural properties of PCIF-1(M4) influenced by different reaction
time.a
Time (h)
SBET [m2 g-1]b
Vp [cm3 g-1]c
Dav [nm]d
12
772
0.48
2.42
24
811
0.55
2.63
36
839
0.57
2.80
48
892
0.72
3.25
72
633
0.47
2.95
[a] Reaction conditions: ClMePOSS (0.5 g, 0.62 mmol), 4,4'-bpy (0.39 g, 2.48 mmol), THF (10
mL), 100 oC, 12~72 h. [b] BET surface area calculated over the range P/P0=0.05~0.20. [c] Total
pore volume calculated at P/P0=0.99. [d] Average pore size calculated by the BET method.
S22
Supplementary Table S2. Textural properties of PCIF-1(M4) influenced by different reaction
temperature.a
Temperature (oC)
SBET [m2 g-1]b
Vp [cm3 g-1]c
Dav [nm]d
80
500
0.26
2.07
90
863
0.55
2.53
100
942
0.76
3.23
110
1025
0.90
3.52
120
865
0.70
3.22
[a] Reaction conditions: ClMePOSS (0.5 g, 0.62 mmol), 4,4'-bpy (0.39 g, 2.48 mmol), THF (10
mL), 80~120 oC, 48 h. [b] BET surface area calculated over the range P/P 0=0.05~0.20. [c] Total
pore volume calculated at P/P0=0.99. [d] Average pore size calculated by the BET method.
S23
Supplementary Table S3. Textural properties of PCIF-1(M4) with different amount of solvent
THF.a
THF volume (mL)
SBET [m2 g-1]b
Vp [cm3 g-1]c
Dav [nm]d
5
763
0.62
3.27
10
892
0.72
3.25
15
886
0.65
2.93
20
843
0.63
3.00
[a] Reaction conditions: ClMePOSS (0.5 g, 0.62 mmol), 4,4'-bpy (0.39 g, 2.48 mmol), THF (5~10
mL), 100 oC, 48 h. [b] BET surface area calculated over the range P/P0=0.05~0.20. [c] Total pore
volume calculated at P/P0=0.99. [d] Average pore size calculated by the BET method.
S24
Supplementary Table S4. Textural properties of PCIF-1(M4) after treated in H2O or various
organic solvents.a
Soaked in solvents
SBET [m2 g-1]b
Vp [cm3 g-1]c
Dav [nm]d
H2O
912
0.73
3.20
CH3OH
886
0.68
3.06
CHCl3
843
0.59
2.96
DMF
856
0.57
2.68
DMSO
866
0.65
2.99
[a] The sample PCIF-1(M4) with the surface area of 942 m2 g-1 and pore volume of 0.76 cm3 g-1
was soaked into various solvents for 24 h at the room temperature, and then was collected by
filtration, washing and drying for further characterizations. [b] BET surface area calculated over the
range P/P0=0.05~0.20. [c] Total pore volume calculated at P/P0=0.99. [d] Average pore size
calculated by the BET method.
S25
Supplementary Table S5. Hydroxylation of benzene to phenol over various catalysts using O2 as
the oxidant.
Entry
Catalyst
Yield of phenol (%)
1
No catalyst, no ascorbic acid
Not detected
2
No catalyst, with ascorbic acid
2.3
3
PCIF-1(M8) (0.25 g)
2.2
4
PMoV (0.035 g)
4.6
5
PMoV@PCIF-1 (0.30 g)
12.0
Reaction condition: 0.8 g ascorbic acid, 2.0 mL benzene, 25 mL aqueous acetic acid solution (50
vol%), 2.0 MPa O2, 100 oC, 10 h.
S26
Supplementary Table S6. Comparison of catalyst recycling performances of this work with
various published heterogeneous catalysts for hydroxylation of benzene with O2.
Catalyst
Phenol yield (%)
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2.5/1.4/0.9
J. Mol. Catal. A: Chem. 208, 203-211 (2004).
LaOx/HZSM-5d
4.2/3.3/3.6
Top. Catal. 47, 98-100 (2008).
CsPMoV2
7.2/5.1/1.3
Ind. Eng. Chem. Res. 44, 1-7 (2005).
bipy2PMoV1e
7.8/5.5/4.2/3.7
Chem. Eng. J. 239, 19-25 (2014).
PMo9V3@HKUST-1f
7.37/7.04/6.40/6.35
Catal. Commun. 35, 101-104 (2013).
POM@MOF@SBA-15
PMoV@PCIF-1
6.0/6.0/5.8/5.9
Micropor. Mesopor. Mater. 195, 87-91 (2014)
12.0/9.3/8.4/6.8
This work
[a] 37.6 % V leaching observed. [b] Vanadium was dissolved obviously into the liquid phase. [c]
The supported vanadium catalysts suffered from the vast leaching of vanadium. [d] HZSM-5:
hydrogen form of ZSM-5 zeolite. [e] bipy: 4,4'-bipyridine. [f] HKUST-1: a stable metal-organic
framework (MOF).
S27
In order to make a detail comparison, Supplementary Table S6 summarizes the initial phenol
yield and recycling performances of the typical previous reported heterogeneous catalysts for
hydroxylation of benzene with O2. Up to now, only very few heterogeneous catalysts have been
reported so far, and they rarely exhibited both high phenol yield and well reusability.
VOx/CuSBA-15 and V-SBA-16 gave the highest phenol yield of more than 20%, but these catalysts
could not be recycled (Appl. Catal. A 328, 150-155 (2007); Catal. Lett. 142, 619–626 (2012)). The
recently
reported
POM
catalysts
including
bipy2PMoV1,
PMo9V3@HKUST-1
and
POM@MOF@SBA-15 gave the improved catalytic recycle performances, but the phenol yields
were modest (Chem. Eng. J. 239, 19-25 (2014); Catal. Commun. 35, 101-104 (2013); Microporous
Mesoporous Mater. 195, 87-91 (2014)). By comparison, the four-run cycle performance of
12.0/9.3/8.4/6.8% over the catalyst PMoV@PCIF-1 is superior to the previously reported
heterogeneous catalytic systems, presenting both relative high phenol yield and well cycle
performance at the current research stage. More importantly, to the best of our knowledge, the TON
value (136) is much higher than all the previous V-POM-based catalysts for homogeneous or
heterogeneous aerobic oxidation of benzene to phenol, further illustrating the high activity of the
obtained PMoV@PCIF-1. In a word, the presented catalyst PMoV@PCIF-1 provided both relative
high initial phenol yield and well cycle performance.
S28