Biomass-Derived Graphene-like Carbon: Efficient Metal-Free Carbocatalysts for Epoxidation

Article abstract of DOI:10.1002/anie.201809970

N-doped graphene-like layered carbon (NG) could be synthesized via a metal-free pyrolysis route from glucose, fructose, and 5-hydroxymethylfurfural (5-HMF), which are cheap and widely available biomass or biomass derivatives. A well-developed thin-layer s

Full text of DOI:10.1002/anie.201809970

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Accepted Article
Title: Biomass-derived graphene-like carbon: an efficient metal-free
carbocatalysts for epoxidation reaction
Authors: Dangsheng Su, Guodong Wen, Qingqing Gu, Yuefeng Liu,
Robert Schlögl, Congxin Wang, and Zhijian Tian
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To be cited as: Angew. Chem. Int. Ed. 10.1002/anie.201809970
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Angewandte Chemie International Edition
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COMMUNICATION
Biomass-derived graphene-like carbon: an efficient metal-free
carbocatalysts for epoxidation reaction
[
a]
[a]
[b]
[c]
[b]
[b]
Guodong Wen,* Qingqing Gu, Yuefeng Liu, Robert Schlögl, Congxin Wang, Zhijian Tian, and
[a,b]
Dang Sheng Su*
[
1a,5]
Abstract: N-doped graphene-like layered carbon (NG) could be
synthesized via a metal-free pyrolysis route from glucose, fructose
and 5-hydroxymethylfurfural (5-HMF), which are cheap and widely
available biomass or biomass derivatives. Among the three kinds of
NG, well-developed thin layered structure with large lateral
dimension could be obtained when 5-HMF was used as the
precursor. More importantly, the 5-HMF derived NG could exhibit
superior performance in epoxidation reactions compared with the
conventional carbon catalysts and the performance of 5-HMF
derived NG was even similar to that of a Co catalyst. Co catalyst is
widely studied in alkene epoxidation reactions. Characterizations by
TEM and XPS accompanied by EPR analysis revealed that the
origin of the enhanced catalytic properties for NG was ascribed to
catalyzed reactions and base-catalyzed reactions.
In this
work, we found that N-doped graphene-like carbon (NG) could
be synthesized from biomass glucose, fructose and 5-HMF,
which are widely available biomass or biomass derivatives.
Although the preparation of NG from glucose has already been
reported, the synthesis of NG from fructose and 5-HMF has not
been reported to the best of our knowledge. More importantly,
these NG materials could be used as efficient metal-free
carbocatalysts in epoxidation reaction.
[
6]
2
the activation ability both for alkene and O , which was attributed to
the graphitic layered structure and graphitic N species, respectively.
Figure 1. TEM images of NG from glucose (a), fructose (b) and 5-HMF (c).
It has been shown that nanocarbon could be applied as
important metal-free catalysts, which is emerging as the
The morphology of the NG from glucose, fructose and 5-HMF
were shown in Fig. 1 and Fig. S1. The NG from glucose
[
1]
alternative to the transition metal-based catalysts.
Many
transition metals are rare, there being issues of sustainability.
Moreover, many metals are toxic to human, thus the metal-free
processes are preferred in the areas such as pharmacy
manufacture. However, the use of metal is still unavoidable in
many processes for these nanocarbon preparation. In order to
keep low level of metal residue, harsh post treatment (e.g.,
inorganic acid washing and high temperature annealing) is
generally involved, which is not environmentally benign and
energy efficient. Therefore, the synthesis of nanocarbon
catalysts via a metal-free route is urgently needed.
(
NG(g1:5)) is small whisker-like flake carbon, larger flake with a
lot of wrinkles could be found from fructose derived NG
(
(
NG(f1:5)), while the lateral dimension of the carbon from 5-HMF
NG(h1:5)) is the largest and thin layers could be observed on it.
All the samples showed typical (002) and (100) graphitic
diffraction peaks (Fig. S2), and the intensity of the (002) peak for
the NG prepared from HMF was weaker than that of the peak for
the NG prepared from glucose and fructose, indicating that the
thickness of continuous orderly stacking for NG prepared from
HMF was thinner. The intensity of the (002) peak decreased with
the increasing of the HMF and urea ratio, indicating that the
thickness of continuous orderly stacking was decreased. The
XRD results are in accordance with the TEM analysis. Then, a
series of 5-HMF derived NG with different urea and 5-HMF
weight ratio in the precursor was prepared. Herein, the prepared
NG was denoted as “NG(x1:y)” wherein x represents the
precursor (“g”, “f” and “h” stands for glucose, fructose and 5-
HMF, respectively) and y represents for the weight ratio between
the urea and precursor. The layered structure is not obvious,
and many amorphous carbons were found on 5-HMF derived
NG(h1:2) and NG(h1:3). With the increasing of the urea and 5-
HMF weight ratio from 5 to 10, obvious layered structure was
observed (Fig. S3) and the degree of graphitization increased as
Biomass, which has low levels of metal content, could be
[
2]
converted to functional carbon materials via a metal-free route.
We have demonstrated that biomass glucose could be
converted to functional carbon materials via a hydrothermal
route and the obtained hydrothermal carbon could be used as
metal-free catalysts in nitrobenzene reduction and Beckmann
[
3]
rearrangement.
García and coworkers have shown that
biomass (e.g., alginic acid sodium salt and chitosan) could be
[1a,4]
converted to graphene-based metal-free catalysts.
It should
be noted that the catalytic properties of graphene-based carbon
are so unique that can catalyze a wide variety of reactions
including hydrogenation reactions, oxidation reactions, acid-
indicated from the decrease of the I
synthesis of NG process, urea was added for the temporary in
situ formation of layered graphitic carbon nitride (g-C ), which
The synthetic
process contains two steps, and the in situ formation of g-C is
favorable in the first step annealing at 600 ºC . The typical
layered structure of C could be observed in the carbon/C
D G
/I ratio (Fig. S4). In the
[
a]
Dr. G.D. Wen, Dr. Qingqing Gu, Prof. Dr. D.S. Su
Shenyang National Laboratory for Materials Science
Institute of Metal Research, Chinese Academy of Sciences
3
N
4
[
2b,6]
72 Wenhua Road, Shenyang 110016 (China)
is likely to serve as a sacrificial template.
E-mail: wengd@imr.ac.cn
3 4
N
dssu@imr.ac.cn
[
b]
c]
Dr. Y.F. Liu, Dr. C.X. Wang, Prof. Dr. Z.J. Tian, Prof. Dr. D.S. Su
Dalian National Laboratory for Clean Energy
Dalian Institute of Chemical Physics, Chinese Academy of Sciences
3
N
4
3 4
N
composite (Fig. S5), which was obtained by calcination of
mixture of 5-HMF and urea at 600 ºC . These results indicated
457 Zhongshan Road, Dalian 116023 (China)
[
Prof. Dr. R. Schlögl
Fritz Haber Institute of the Max Planck Society
Faradayweg 4-6, Berlin 14195 (Germany)
that the polymeric plane of C
3 4
N was well developed in the
presence of 5-HMF or 5-HMF-derived intermediates. The
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Angewandte Chemie International Edition
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COMMUNICATION
formation of C
3
N
4
could also be confirmed from the TG analysis
was obtained. It was reported that the solvent DMF could
coordinate with Co sites to form the true active sites and/or
shown in Fig. S6. A rapid weight loss was observed at the
temperatures higher than 600 ºC, which could be attributed to
[9b,10]
acting as a co-reductant,
thus DMF was often selected as
the pyrolysis of C
3
N
4
. 5-HMF, which is an intermediate during
the optimum solvent for the Co catalysts. As expected, both the
conversion (4.5%) and selectivity (87.7%) were significantly
increased when the solvent was changed from cyclohexanone to
DMF. Although the styrene oxide selectivity on NG(h1:10) was
lower than that on CoOx, higher conversion was observed on
NG(h1:10), thus similar yield was obtained.
the degradation of glucose or fructose, is prone to polymerize or
aromatize to carbonaceous structure as compared to glucose
[
7]
and fructose. When 5-HMF was used as the precursor for NG
preparation, the carbon yield was 6.7%. In contrast, the yield
was only 3.6% when fructose was used as the precursor.
Therefore, the well-developed thin layered structure with large
lateral dimension shown in the TEM images when 5-HMF was
used as the precursor was probably ascribed to the easy
polymerization of 5-HMF.
[
a]
Table 1. Epoxidation of styrene over different carbon catalysts.
Catalyst
Conv.
%
Styrene oxide
selectivity (%)
Benzaldehyde
selectivity (%)
Styrene oxide
yield (%)
NG(h1:10)
7.9
10.3
0.0
0.0
0.0
0.2
0.0
0.0
4.5
44.7
0.0
0.0
0.0
0.0
0.0
0.0
0.0
87.7
54.2
100.0
0.0
3.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
4.0
RGO
Activated carbon
Nanodiamond
0.0
C
3
N
4
0.0
CNT
100.0
0.0
Flake graphite
CoOx
0.0
[
b]
CoOx
12.3
[
a] Reaction conditions: 1 mmol styrene, 10 mL solvent cyclohexanone, 50 mg
catalyst, 60 °C , 8 h, 0.1 MPa, O flow rate 10 mL/min. [b] The solvent is DMF.
2
Figure 2. N1s XPS spectra of NG(h1:2), NG(h1:3), NG(h1:5), NG(h1:7) and
NG(h1:10).
Then the effect of solvents was studied (Fig. S9), the results
indicated that high conversion and selectivity could be obtained
in cyclohexanone, and almost no conversion was observed
when DMF, toluene and acetonitrile were used as the solvents.
The effect of pyrolysis precursor was also studied (Fig. S10).
Low conversion and no styrene oxide formation were observed
when glucose and fructose were used as the precursor. In
contrast, higher conversion was obtained, and selectivity as high
as 49.8% could be observed on NG derived from 5-HMF. It was
shown in Fig. S8 and Table S1 that similar surface N contents
were observed on NG derived from these precursors. It seems
that the improved performance on 5-HMF derived NG was
ascribed to its unique structure, namely well-developed thin
graphitic layered structure. In order to exclude the catalytic roles
of underlying metal residues, the metal content in these three
NG was qualified by ICP-MS and quantified by ICP-AES. The
results showed that Fe was the possible impurity, and the Fe
contents in NG derived from glucose, fructose and 5-HMF were
The surface N element distribution was investigated by
energy-dispersive X-ray (EDX) mapping. As shown in Fig. S7, a
uniform N distribution has been achieved on the NG(h1:10)
catalyst. The N1s XPS spectra were shown in Fig. 2 and Fig. S8.
The deconvolution of the spectra was similar to that reported by
[
8]
Arrigo et al., Chen et al. and our previous work. It could be
found that the graphitic N content gradually increased from 1.6
at% to 3.1 at%, while the pyridinic N content remained almost
unchanged when the urea and 5-HMF weight ratio increased
from 2 to 10 (Table S1). The pyrrole-like N content increased
from 1.5 at% to 2.1 at% when the ratio increased from 2 to 3,
and then slowly decreased with the further increase of the ratio.
These results indicated that the content of surface N species
could be well tuned by increasing the urea and precursor ratio.
The NG was tested in the aerobic epoxidation of styrene to
styrene oxide. Benzaldehyde were identified as the primary
byproduct from the GC-MS analysis, other minor byproducts
were phenylacetadehyde, benzoic acid and 1-phenylethane-1,2-
diol. It could be found from Table 1 that almost no conversion
127 ppm, 79 ppm and 101 ppm, respectively. The Fe content is
not correlated with the performance, which further confirmed that
the metal impurities have a minor effect on the performance of
the NG catalysts.
3 4
was observed on activated carbon, nanodiamond, C N and
flake graphite. Extremely low conversion (0.2%) was obtained
on CNT. It is very interesting to note that high conversion (10.3%)
was observed on reduced graphene oxide (RGO), albert no
styrene oxide was detected, which demonstrated the critical
roles of N doping for the epoxidation reactions. Herein, a
simple Co catalyst CoOx was prepared. However, no conversion
In order to study the roles of different N species, the catalytic
performance of the five NG catalysts prepared from 5-HMF with
different N species contents was investigated. The conversion
increased with the increase of the urea and 5-HMF ratio from 2
to 10 (Table 2), which is in accordance with the increase of the
[
9]
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Angewandte Chemie International Edition
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COMMUNICATION
graphitic N content. These results suggested that the graphitic N
was closely related to the activities, which was likely to be
radicals, because the signals of several radicals overlapped with
•
each other. It seems that Ph-CH(CH
2
) DMPO-trapped species
ascribed to the activation ability for O
2
as reported from DFT
and hydrogen radical trapped DMPO-H species were formed,
because the radical signals were very similar to that reported by
Shimakoshi and coworkers.
calculations and in situ high-resolution
synchrotron
[
1c,11]
[12]
techniques.
A possible mechanism was proposed (Fig. 4), styrene was
[
a]
•
Table 2. Epoxidation of styrene over 5-HMF derived NG.
activated on graphitic layer surface to form Ph-CH(CH
2
) radical,
2
O was activated on the carbon adjacent to the graphitic N. The
graphitic N has an unpaired electron that delocalized over the
basal plane of graphene, which provided the possibility for
Catalyst
Conv.%
Styrene oxide
selectivity (%)
Benzaldehyde
selectivity (%)
Styrene oxide
yield (%)
NG(h1:2)
NG(h1:3)
NG(h1:5)
NG(h1:7)
NG(h1:10)
0.1
0.3
5.9
7.2
7.9
0.0
0.0
100.0
100.0
49.7
0.0
0.0
3.0
3.3
3.5
electron transfer from the adjacent carbon atoms to the O
2
to
•
[1c,13]
form O
2
radical.
Then the two radicals interacted with each
•
other to form Ph-CH(CH
2
)OO radical, followed by the
dissociation of O-O bond to form styrene oxide. In this process,
both the graphitic layered structure and graphitic N species are
critical.
49.8
45.2
44.7
53.1
54.2
[
a] Reaction conditions: 1 mmol styrene, 10 mL solvent cyclohexanone, 50
mg catalyst, 60 °C, 8 h, 0.1 MPa, O flow rate 10 mL/min.
2
Figure 4. Possible mechanism for the epoxidation of styrene over NG
catalysts.
The ATR-IR spectra showed that there was an interaction
between the styrene and solvent cyclohexanone, because the
-1
characteristic peaks at 697 and 776 cm , which is the indicative
of mono substituted benzene ring, were shifted to lower
wavenumbers when cyclohexanone was added into styrene (Fig.
Figure 3. EPR spectra of styrene epoxidation on NG(h1:10) and RGO at room
temperature (RT) or 60 °C in O or N
2
2
.
-1
S12a). The peak at 1630 cm could be attributed to C=C
vibration of styrene, and its intensity gradually decreased with
the increasing of the reaction time from 30 min to 6 h (Fig. S12b
and Fig. S13a), indicating the gradual conversion of styrene. A
Radicals were generally involved in the aerobic oxidation
[
1c,1d]
reactions over carbon catalysts.
The electron paramagnetic
resonance (EPR) technology was adopted to detect the radical
intermediates. When no catalyst was added in the reaction, the
signal was so weak that could be neglected (Fig. S11). Similar
spectra were shown in Fig. 3c and 3e, indicating that both the
NG and RGO catalysts have the ability to activate styrene to
radicals, thus the activation of styrene is correlated with the
graphitic layered structure, which is similar to that reported by
-1
shoulder peak appeared at 758 cm (Fig. S12c), which is the
indicative of mono substituted benzene ring of styrene oxide,
indicating the formation of styrene oxide during the reaction over
-1
NG(h1:10) catalyst. In contrast, no shoulder peak at 758 cm
was appeared when RGO was used as catalyst (Fig. S13b). A
-1
small peak at 1140 cm was formed when NG(h1:10) was used
as catalyst, its intensity increased from 30 min to 2 h, and then
decreased with the further increase of the reaction time. This
signal is probably indicative of a stretching vibration of C-O-O
[
1d]
2
Peng and coworkers. When O was introduced in the reaction,
the radical signal over the RGO catalyst was severely
attenuated (Fig. 3d), indicating that many radicals were quickly
[
14]
reacted with
2
O molecules to form side product, namely
bonds in alkyl peroxides, which strongly support the formation
•
benzaldehyde. In contrast, the intensity of the signal was not
obviously attenuated and some part of the signal was even
2
of Ph-CH(CH )OO radical intermediate.
The effect of reaction time (Fig. S14) and temperature (Fig.
S15) were also studied, and a styrene oxide yield of 24.2%
could be obtained at 80 °C for 8 h, which was similar to that
reported by Dhakshinamoorthy and coworkers from the
chitosan-derived NG (the yield given at 100 °C for 8 h was
intensified over the NG(h1:10) catalyst when O
2
was introduced
(
Fig. 3b). These results suggested that O could be activated on
2
NG(h1:10) catalyst at 60 °C, but could not be activated on RGO
catalyst. It is very difficult for us to clearly identify the different
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Angewandte Chemie International Edition
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COMMUNICATION
[
4b]
1
7.8%). Various alkenes including trans-stilbene, cyclohexene
51521091, 21473223) and Strategic Priority Research Program
of the Chinese Academy of Sciences (No. XDA09030103).
and 1-hexene were tested as substrate. Extremely high
conversion (80.4%) and selectivity (84.5%) could be observed
when trans-stilbene was used as the substrate, however the
yield was low when cyclohexene and 1-hexene were used as
the substrates, which were only 8.0% and 0.7%, respectively.
These results indicated that the epoxidation reaction could be
well conducted on C=C bond that connected with benzene ring,
which might be ascribed to the conjugated π systems. Moreover,
it was found that the NG(h1:10) catalyst is relatively stable
during the recycle test (Fig. S16).
In conclusion, we have shown that NG could be prepared
from glucose, fructose and 5-HMF, which are widely available
biomass or biomass derivatives. Among the three kinds of NG,
well-developed thin layered structure with large lateral
dimension could be obtained when 5-HMF was used as the
precursor. More importantly, the 5-HMF derived NG could
exhibit superior performance in epoxidation reactions compared
with the conventional carbon catalysts and the performance of 5-
HMF derived NG was even similar to that of a Co catalyst
Keywords: biomass • graphene • metal-free • carbocatalysts •
epoxidation reaction
[
1]
a) S. Navalon, A. Dhakshinamoorthy, M. Alvaro, M. Antonietti, H.
García, Chem. Soc. Rev. 2017, 46, 4501-4529; b) X. G. Duan, H. Q.
Sun, S. B. Wang, Acc. Chem. Res. 2018, 51, 678-687; c) D. S. Su, G.
D. Wen, S. C. Wu, F. Peng, R. Schlögl, Angew. Chem. 2017, 129, 956-
9
85; Angew. Chem. Int. Ed. 2017, 56, 936-964; d) H. Yu, F. Peng, J.
Tan, X. W. Hu, H. J. Wang, J. Yang, W. X. Zheng, Angew. Chem. 2011,
23, 4064-4068; Angew. Chem. Int. Ed. 2011, 50, 3978-3982; e) D.
Chen, A. Holmen, Z. J. Sui, X. G. Zhou, Chin. J. Catal. 2014, 35, 824-
41; f) E. García-Bordejé, Y. F. Liu, D. S. Su, C. Pham-Huu, J. Mater.
1
8
Chem. A 2017, 5, 22408-22441.
[2]
a) M. M. Titirici, R. J. White, N. Brun, V. L. Budarin, D. S. Su, F. del
Monte, J. H. Clark, M. J. MacLachlan, Chem. Soc. Rev. 2015, 44, 250-
290; b) X. H. Li, S. Kurasch, U. Kaiser, M. Antonietti, Angew. Chem.
2012, 124, 9827-9830; Angew. Chem. Int. Ed. 2012, 51, 9689-9692.
[
3]
4]
G. D. Wen, B. L. Wang, C. X. Wang, J. Wang, Z. J. Tian, R. Schlögl, D.
S. Su, Angew. Chem. 2017, 129, 615-619; Angew. Chem. Int. Ed. 2017,
(
CoOx). Co catalyst is widely studied in the epoxidation
56, 600-604.
reactions. Characterizations by TEM and XPS accompanied by
EPR analysis suggested that the origin of the enhanced catalytic
properties for NG was ascribed to the activation ability both for
[
a) A. Primo, F. Neatu, M. Florea, V. Parvulescu, H. García, Nat.
Commun. 2014, 5, 5291; b) A. Dhakshinamoorthy, A. Primo, P.
Concepcion, M. Alvaro, H. García, Chem. Eur. J. 2013, 19, 7547-7554.
a) P. Tang, G. Hu, M. Z. Li, D. Ma, ACS Catal. 2016, 6, 6948-6958; b)
D. R. Dreyer, S. Park, C. W. Bielawski, R. S. Ruoff, Chem. Soc. Rev.
alkene and O
2
, which were probably resulted from the graphitic
[5]
layered structure and graphitic N species, respectively. The
mechanism understanding for the carbon catalysts is different
from that for the conventional metal-based catalysts, which is
helpful to shed some light on the mechanism research of metal-
free catalysis.
2
010, 39, 228-240; c) F. Hu, M. Patel, F. X. Luo, C. Flach, R.
Mendelsohn, E. Garfunkel, H. X. He, M. Szostak, J. Am. Chem. Soc.
015, 137, 14437-14480.
a) C. Chen, G. B. Xu, X. L. Wei, L. W. Yang, J. Mater. Chem. A 2016, 4,
900-9909; b) Q. P. Zhao, Q. Ma, F. P. Pan, Z. M. Wang, B. P. Yang, J.
Q. Zhang, J. Y. Zhang, J. Solid State Electrochem. 2016, 20, 1469-
479.
a) E. B. Sanders, A. I. Goldsmith, J. I. Seeman, J. Anal. Appl. Pyrolysis
003, 66, 29-50; b) M. M. Titirici, R. J. White, C. Falco, M. Sevilla,
2
[
6]
9
1
Experimental Section
[7]
2
Energy Environ. Sci. 2012, 5, 6796-6822; c) C. Falco, F. P. Caballero,
F. Babonneau, C. Gervais, G. Laurent, M. M. Titirici, N. Baccile,
Langmuir 2011, 27, 14460-14471.
Nitrogen-doped graphene-like layered carbon (NG) was synthesized as
follows: first, the biomass precursor (glucose, fructose or 5-HMF) was
dissolved into saturated urea aqueous solution, follow by drying at 60 °C.
The obtained solid was transferred into a tubular furnace for pyrolysis
under Ar flow (100mL/min). The sample was heated to 600 °C at a
heating rate of 1 °C /min and maintained at this temperature for 1 h, then
calcined at 900 °C for 1 h at a heating rate of 1 °C /min. The solid was
dispersed in deionized water, sonicated at 237.5 W for 1 h, and finally
dried at 60 °C .
The epoxidation reaction was conducted in the presence of 1 mmol
2
substrate, 10 mL solvent and 50 mg catalyst with O flow (10 mL/min) at
atmosphere pressure at the temperatures ranging from 50 °C to 100 °C
under vigorous stirring. Full experimental details can be found in the
Supplementary information.
[
8]
a) R. Arrigo, M. Hävecker, S. Wrabetz, R. Blume, M. Lerch, J.
McGregor, E. P. J. Parrott, J. A. Zeitler, L. F. Gladden, A. KnopGericke,
R. Schlögl, D. S. Su, J. Am. Chem. Soc. 2010, 132, 9619-9630; b) C. L.
Chen, J. Zhang, B. S. Zhang, C. L. Yu, F. Peng, D. S. Su, Chem.
Commun. 2013, 49, 8151-8153; c) G. D. Wen, J. Y. Diao, S. C. Wu, W.
M. Yang, R. Schlögl, D. S. Su, ACS Catal. 2015, 5, 3600-3608; d) G. D.
Wen, S. C. Wu, B. Li, C. L. Dai, D. S. Su, Angew. Chem. 2015, 127,
4178-4182; Angew. Chem. Int. Ed. 2015, 54, 4105-4109.
[9]
a) H. J. Zhan, Q. H. Xia, X. H. Lu, Q. Zhang, H. X. Yuan, K. X. Su, X. T.
Ma, Catal. Commun. 2007, 8, 1472-1478; b) Q. H. Tang, Q. H. Zhang,
H. L. Wu, Y. Wang, J. Catal. 2005, 230, 384-397.
[
10] Z. Opre, T. Mallat, A. Baiker, J. Catal. 2007, 245, 482-486.
11] M. Scardamaglia, T. Susi, C. Struzzi, R. Snyders, G. Di Santo, L.
Petaccia, C. Bittencourt, Sci. Rep. 2017, 7, 7960.
[
Acknowledgements
[12] H. Shimakoshi, Z. L. Luo, K. Tomita, Y. Hisaeda, J. Organomet. Chem.
017, 839, 71-77.
2
[
13] X. X. Yang, Y. H. Cao, H. Yu, H. Y. Huang, H. J. Wang, F. Peng, Catal.
Sci. Technol. 2017, 7, 4431-4436.
We thank Jiafu Chen and Yonghai Cao for EPR measurement,
Laipeng Ma and Qinwei Wei for AFM test, and Xiaochun Liu for
HR-TEM analysis. This work was supported by the National
Natural Science Foundation of China (21503241, 21411130120,
[14] X. X. Yang, H. J. Wang, J. Li, W. X. Zheng, R. Xiang, Z. K. Tang, H. Yu,
F. Peng, Chem. Eur. J. 2013, 19, 9818-9824.
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Angewandte Chemie International Edition
10.1002/anie.201809970
COMMUNICATION
COMMUNICATION
N-doped graphene-like layered carbon
Guodong Wen,* Qingqing Gu, Yuefeng
Liu, Robert Schlögl, Congxin Wang,
Zhijian Tian, Dang Sheng Su*
(
NG) could be synthesized via a
metal-free pyrolysis route from
glucose, fructose and 5-HMF, which
are widely available biomass or
biomass derivatives. Well-developed
thin layered structure with large lateral
dimension could be observed on 5-
HMF derived NG, which could be
used as metal-free catalysts in alkene
epoxidation. The origin of the activities
was resulted from the graphene layer
and graphitic N species.
Page No. – Page No.
Biomass-derived graphene-like
carbon: an efficient metal-free
carbocatalysts for epoxidation
reaction
This article is protected by copyright. All rights reserved.