Preparation of manganese/Graphite oxide composite using permanganate and graphite: Application as catalyst in bromination of hydrocarbons

Article abstract of DOI:10.1246/bcsj.20160346

A highly efficient one-pot preparation of manganese/graphite oxide (MnO_X/GO) composite from graphite and KMnO4 is described. Hummers preparation method of GO requires a stoichiometric amount of KMnO4, as a result, the method produces a large amount of reduced Mn species. The Mn residue generally is a waste, therefore, we envisioned converting it to value-Added materials. A MnO_X/GO composite was prepared in one-pot by treating the unpurified GO with aqueous KOH. The composite was characterized by XRD, XAFS, SEM and TEM. Among various applications of the MnO_X/GO composite, we applied it as a recyclable catalyst for bromination of saturated hydrocarbons, one of the most basic but important chemical transformations. The MnO_X/GO composite is expected to be an efficient catalyst because of the high surface area and high accessibility of substrates derived from the 2- dimensional sheet structure. When the reaction of a saturated hydrocarbon and Br2 in the presence of catalytic MnO_X/GO was performed under fluorescent light irradiation, a brominated product was formed in high yield in a short reaction time. GO could strongly bind with Mn to prevent elution to the liquid phase, enabling the high recyclability.

Full text of DOI:10.1246/bcsj.20160346

Advance Publication Cover Page
Preparation of Manganese/Graphite Oxide Composite Using Permanganate and
Graphite: Application as Catalyst in Bromination of Hydrocarbons
Hideyuki Suzuki and Yuta Nishina*
Advance Publication on the web October 21, 2016
doi:10.1246/bcsj.20160346
© 2016 The Chemical Society of Japan

Preparation of manganese/graphite oxide composite using permanganate and
graphite: application as catalyst in bromination of hydrocarbons
Hideyuki Suzuki, 1 and Yuta Nishina, 1, 2
*
1
Research Core for Interdisciplinary Sciences, Okayama University, 3-1-1, Tsushimanaka, Kita-ku, Okayama 700-8530, Japan
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, 4 -1-8 Honcho, Kawaguchi, Saitama
2
332-0012, Japan
E-mail: nisina-y@cc.okayama-u.ac.jp
Yuta Nishina
Dr. Yuta Nishina is an associate professor at Okayama University, Japan. He started his research on organic chemistryat
Okayama University supervised by Prof. Kazuhiko Takai. During his Ph.D. course, he joined in the research groups in MIT
and Kobe University. He obtained Ph.D. on 2010, and started his academic carrier as assistant professor at Okayama
University, and promoted to associate professor on 2014. From2013, he has been supported by JST PRESTO (Molecular
technology and creation ofnew functions) for the application ofnanocarbons, especially graphene oxide, froma view point
of organic and materials chemistry
Abstract
nanoparticles (NPs) by treating with a base.
A
highly efficient
one-pot
preparation of
Among various application ofmetal/GO composites, we
focused on catalysis in organic synthesis, which has been
extensively studied within the past few years [26–31]. One ofthe
most important catalytic reactions is the direct transformation of
simple hydrocarbons to value-added chemicals. Organic
bromides are valuable compounds, since they have been widely
used as starting materials and intermediates in organic synthesis.
In the conventional method, organic bromides are synthesized
from the corresponding alcohols with HBr [32], PBr3 [33], or
other brominating reagents [34–37]. Although they can be
synthesized from corresponding hydrocarbons using high
temperature treatment [38], photo irradiation [39],
stoichiometric amount ofadditives [40–42], and catalysts [43],
no practical method to meet the requirements ofselectivity and
efficiency has been proposed. We previously reported that
Li2MnO3 showed superior performance than conventional
methods in the bromination ofhydrocarbons [44], however, the
reaction still required 10 mol% loading ofthe catalyst due to the
low surface area ofthe catalyst. Because ofthe high surface area
and high accessibility of substrates derived from the 2-
dimensional sheet and nanoparticle structure, the MnOX/GO
composite is expected to be a much more efficient catalyst.
manganese/graphite oxide (MnOX/GO) compositefromgraphite
and KMnO4 was described. Hummers’ preparation method of
GO requires a stoichiometric amount ofKMnO4, as a result, the
method produces a large amount ofreduced Mn species. The Mn
residue generally is a waste, therefore, we envisioned converting
it to value-added materials. A MnOX/GO composite was
prepared in one-pot by treating the unpurified GO with aqueous
KOH. The composite was characterized by XRD, XAFS, SEM
and TEM. Among various application of the MnOX/GO
composite, we applied as a recyclable catalyst for bromination
of saturated hydrocarbons, one ofthe most basic but important
chemical transformations. The MnOX/GO compositeis expected
to be an efficient catalyst because ofthe high surface area and
high accessibility ofsubstrates derived fromthe 2-dimensional
sheet structure. When the reaction of a saturated hydrocarbon
and Br2 in the presence of catalytic amount ofMnOx/GO was
performed under fluorescent light-irradiation, a brominated
product was formed in high yield in a short reaction time. GO
could strongly bind with Mn to prevent elution to the liquid
phase, enabling the high recyclability.
1. Introduction
2. Experimental
Graphite oxide (GO) has high surface area, good
dispersibility, mechanical stability, and a number of oxygen-
containing functional groups on the plane and edges of a
graphene sheet [1,2]. Because of the attractive chemical and
physical properties, the application ofGO has expanded from
material sciences to biological sciences [3–10]. To improve the
performance of GO, composites with metals have been
investigated [3,11]. Here, we focused on a facile approach to
MnOX/GO composites. MnOX/GO composites have been
prepared by the hydrothermal method [12–15] using a Mn salt
and GO, and have subsequently been used as a catalyst [16],
lithium-ion battery electrodes [17, 18], and supercapacitor
electrodes [19–24]. We conceived the idea for more efficient
preparation ofMnOX/GO when we prepared GO by Hummer’s
method [25]. The method requires a stoichiometric amount of
KMnO4 to oxidize graphite, and produces a large amount ofMn
salt as a byproduct. Such Mn salt can be transformed to
2.1. Materials
Graphite(SP-1 grade)was purchasedfromBAY CARBON
Inc. KMnO4, Br2, hexane, benzene, and toluene were purchased
from Wako Pure Chemical Industries, Ltd. Cyclohexane was
purchased fromNacalai Tesque,Inc.Cyclooctanewas purchased
from Aldrich Chemical Co. Adamantane and N-
bromosuccinimide were purchased from Tokyo Chemical
Industries Co., Ltd. These materials were used as received.
2.2. Methods
X-ray diffraction (XRD) was measured by PANalytical
X’Pert-ProMPD using Cu Kα radiation. X-ray absorption near-
edge structure (XANES) data were collected using beamline
BL14B2 at SPring-8. Commercially available MnO2, Mn2O3,
Mn3O4, MnO and MnBr2 were measured as standard samples.
Data were analyzed with the Athena software program. Nuclear
magnetic resonance (NMR) spectra were recorded using a

Varian NMR System 600 spectrometer. Transmission electron
microscope (TEM) images were recorded using a JEOL JEM-
2100F and collected fromsample powder dispersed on a carbon-
coated copper grid. Scanning electron microscope (SEM)
images were obtained using a JEOL JSM-IT100 by dispersing
the sample on a silicon wafer. Energy dispersive X-ray
spectroscopic (EDS) measurements were performed on a SEM
(JEOL JSM-IT100) equipped with an energy dispersive X-ray
analyzer.
S1). Mn was uniformly distributed on GO, as determined by
elemental mapping using SEM-EDS (Fig 3). The nanostructure
of the MnOX/GO was observed by TEM (Fig S3a).
We applied the MnOX/GO composite to the direct
bromination ofhydrocarbons. The reaction ofcyclohexane (1a)
with bromine in the presence ofcatalytic MnOX/GO proceeded
to afford the mono-brominated product 2a in 83% yield (Scheme
1). The recovered catalyst was analyzed by TEM, SEM, and
XRD. Consequently, Mn NPs were not observed (Fig S3b, S5a),
and no peak ofMn3O4 was observed by XRD (Fig 1b). However,
we confirmed by atomic absorption analysis that little Mn was
eluted into the reaction media, and SEM-EDS analysis also
revealed that Mn remained on GO (Fig S5d). In a previous report,
Mn oxide was transformed into MnBr2 under similar reaction
conditions [44]. SEM-EDS measurement of the recovered
MnOx/GO catalyst showed the uniformdistribution ofMn and
Br, which supports the formation ofa Mn-Br bond (Fig S5). To
determine the structure ofMn ofthe recovered catalyst, XANES
analysis was again performed, however, the spectrumwas not
consistent with MnBr2 (Fig 2Ba, 2Bc), and theaverage oxidation
state ofMn became +2.8 (Fig S1). Therefore, we speculate that
the Mn is connected to Br and oxygen functional groups ofGO,
which prevented the elution of Mn from GO surface. To
regenerate Mn NPs, the catalyst was treated again with aqueous
KOH, as a result, the XRD pattern recovered and the pattern was
consistent with that of Mn3O4/GO (Fig 1c). TEM and SEM
analysis also confirmed the recovery ofMn NPs (Fig S3, S6).
XANES analysis revealed that KOH treatment changed the
oxidation state ofMn from+2.8 to +3.5 (Fig 2Bb, S1).
2.3. Preparation of manganese/graphite oxide (MnOX/GO)
composite
To a dispersion ofgraphite (3.0 g) in 95% H2SO4 (75 mL)
was slowly added KMnO4 (9.0 g) at <10 ˚C, and the reaction
mixture was stirred at 35 ˚C for 2 h. The resulting mixture was
diluted by water (75 mL) under vigorous stirring and cooling so
that temperature does not exceed 50 ˚C. After 30 min, the
suspension was transferred to a centrifuge tube with additional
water (40 mL) and centrifuged. After removing the 140 mL of
supernatant, water (100 mL) was added. To a part of the
suspension (10 mL) was slowly added aqueous KOH (3 M,
30 mL) at 0 ˚C, and the mixture was stirred at roomtemperature
for a few minutes under air. The MnOX/GO was filtered offand
washed with excess H2O, followed by drying under vacuum.
2.4. General procedure for bromination of hydrocarbons
with MnOX/GO
To a solution ofMnOX/GO (2.00 mg, Mn: 0.011 mmol) in
a hydrocarbon was added Br2 (1.00 mmol) at roomtemperature,
and the reaction mixture was stirred at 80 ˚C for 1 h under air
with fluorescent light-irradiation. To this was added dodecane
(227 L, 1.00 mmol) as an internal standard, diluted with ethyl
acetate, and the product yield was determined by GC.
2.5. Procedure for catalyst recycling
After completion of the reaction, aqueous KOH (2 M,
0.75 mL) was added and stirred for 5 min. The catalyst was
filtered off and washed with H2O and ethyl acetate, followed by
drying under vacuum. The catalyst could be directly used in the
next cycle under the same reaction conditions.
3. Results and Discussion
Gao, Qiu and co-workers have reported efficient synthesis
methods of MnOx/GO composites using residual Mn of
Hummers’ method [23, 24 , 45, 46]. Our method is similar to
their concept, but more simplified. Graphite was treated with
KMnO4 in sulfuric acid at 35 °C for 2 h, where graphite was
oxidized and Mn was reduced, and then water was added. In the
conventional Hummers’ method for the preparation ofGO [25],
H2O2 is added at this stage to remove the residual Mn. In contrast,
we added aqueous KOH to precipitate Mn NPs on GO. Atomic
absorption analysis revealed that 30 wt% ofMn was contained
in theMnOX/GO,whichcorrespondsto theincorporation of70%
of Mn from KMnO4 used for the oxidation ofgraphite [47]. The
amount of Mn on GO could be reduced to 10 wt% by partially
removing the residual Mn by centrifugation before the addition
of aqueous KOH.
Figure 1. XRD patterns of(a) fresh MnOX/GO, (b) recovered
MnOX/GO, (c) recovered MnOX/GO after KOH treatment, (d)
Mn3O4, and (e) GO.
As prepared MnOX/GO was characterized by XRD (Fig
1a). A peak at 2θ = 11.0° corresponds to GO (002), and other
peaks were completely consistent with Mn3O4 (Fig 1d).
However, the XANES spectra ofthe MnOX/GO (Fig 2Aa) was
different from those of pure Mn3O4 (Fig 2Ac) and other
manganese oxides (Fig 2Ab, 2Ad, 2Ae). We assumed that some
ofMn in the MnOX/GO were crystalline Mn3O4, and others were
amorphous or ionic Mn species. The oxidation state ofMn in
MnOX/GO was determined to be +3.0 by XANES analysis (Fig
Figure 2.
Mn K-edge XANES spectra of (A) (a) fresh
MnOX/GO, (b) MnO, (c) Mn3O4, (d) Mn2O3, (e) MnO2; (B) (a)

recovered MnOX/GO, (b) recovered MnOX/GO after KOH
treatment, and (c) MnBr2·nH2O.
Table 1. Optimization studies.a
Yield (%) b
Entry Mn catalyst Conditions
2
3
1
MnOX/GO
MnOX/GO
MnOX/GO
MnOX/GO
MnOX/GO
MnOX/GO
Mn3O4
hν, 80 ˚C, air
hν, 60 ˚C, air
hν, 80 ˚C, Ar
hν, 80 ˚C, O2
66
20
49
66
6
Figure 3. Micrographs offresh MnOx/GO composite. (a) SEM
image, and elemental distribution of(b) carbon, (c) oxygen, and
(d) manganese.
2
< 1
3
3
4
7
5
dark, 80 ˚C, air N.D.
N.D.
5
Scheme 1. Direct bromination ofcyclohexane.
To optimize the bromination conditions, we investigated
thereaction temperature,atmosphere.It was reported that theBr2
is activated on the Mn surface by light [42, 44], therefore, we
also evaluated the effect of light. When the reaction was
performed at 80 °C for 1 h under air and fluorescent light-
irradiation, 2a and trans-1,2-dibromocyclohexane (3a) were
formed in 66% and 6% yields, respectively (Table 1, entry 1). In
contrast, lowering the temperature to 60 °C afforded 2a in only
20% yield (Table 1, entry 2). The product yield was decreased
under an Ar atmosphere, but an oxygen atmosphere did not have
any positive effect on the reaction (Table 1, entries 3 and 4).
Light was important for the reaction (Table 1, entry 5), because
activation ofBr2 requires light of 380–500 nmwavelength [48].
When the ratio of1a with bromine was increased, the yield of2a
increased to 83% and formation of3a was suppressed (Table 1,
entry 6). For comparison, other bulky Mn oxides, such as Mn3O4
(29 m), MnO2 (1.9 m), Mn2O3 (1.2 m), and MnO (5.9 m),
were used as a catalyst, but product yields were low (Table 1,
entry 7, and Table S2). When MnBr2/GO, prepared fromMnBr2
and GO by evaporation to dryness method, and MnOx/GO
treated by HBr or Br2 were used as catalysts, the product yields
were only 27%, 6%, and 18%, respectively (Table 1, entries 8-
10). These results suggest that Mn should not be large particles,
and Mn-Br structure is not preferred. Free radical bromination
without any catalyst proceeded under light irradiation, but the
yield and selectivity were low (Table 1, entry 11).
6 c
hν, 80 ˚C, air
hν, 80 ˚C, air
hν, 80 ˚C, air
hν, 80 ˚C, air
83
5
7
< 1
1
8
MnBr2/GO
27
6
MnOX/GO-
HBr
9
1
MnOX/GO-
Br2
10
11
hν, 80 ˚C, air
hν, 80 ˚C, air
18
11
1
7
None
aAll reactions were performed using 1.0 mL of
cyclohexane (1a), 0.052 mL (1.0 mmol) of Br2, and 2.0 mg of
MnOX/GO (Mn: 0.011 mmol) at 80 °C for 1 h under air with
fluorescent light-irradiation. bYields were determined based on
the moles ofBr2 by GC using n-dodecane as an internal standard.
cThe reaction was performed using 2.0 mL of 1a., N.D. = Not
Detected.
We next investigated the substrate scope (Table 2). Cyclooctane
(1b), n-hexane (1c) and toluene (1d) were successfully
brominated in high yield in a short reaction time (Table 2, entries
1─3). In contrast, this catalytic system was not suitable for
sterically hindered substrates such as adamantane (1e) (Table 2,
entry 4). Bromination of benzene (1f) did not proceed at all
(Table 2, entry 5). When 1d was used, only the benzyl position
was brominated (Table 2, entry 3). These results suggest that the
reaction passes through a radical intermediate, because
bromination of aromatic moiety proceeds via electrophilic
substitution with cationic bromine intermediate.

Table 2. Scope ofsubstrates for MnOX/GO-catalyzed bromination.a
Entry
Substrate
Time
Product b
1
10 min
92%
1b
2b
2c
2
3
10 min
2c’
1c
75% (2c : 2c’ = 1.6 : 1) c
2 min
98%
1d
2d
d
4
24 h
1e
2e
2e’
11%
4%
5
2 h
< 1%
1f
2f
aAll reactions were performed using 2.0 mL of 1, 0.052 mL (1.0 mmol) of Br2, and 2.0 mg of MnOX/GO (Mn: 0.011 mmol) at
80 °C under air with fluorescent light-irradiation. bYields were determined based on the moles ofBr2 by GC using n-dodecane as an
1
internal standard. cThe product ratio was determined by H NMR. d1e was used in 2.0 equiv. of Br2 and CHCl2CHCl2 (2 mL) as a
solvent.
Finally, we explored the reusability of MnOX/GO in the
bromination of 1a. After completion of the reaction, aqueous
KOH was added before product yield was determined by GC.
The catalyst was recovered by filtration and washed with H2O
and ethyl acetate, followed by drying under vacuum. The
catalyst could be directly used in the next recycle under the same
reaction conditions. The yields of 2a and 3a were almost
consistent forfivecycles withoutleaching Mn in theliquidphase
(Fig 4).

16. W. Zheng, R. Tan, L. Zhao, Y. Chen, C. Xiong, D. Yin,
RSC Adv. 2014, 4, 11732.
17. Y. Sun, X. Hu, W. Luo, F. Xia,Y. Huang, Adv. Funct. Mater.
2013, 23, 2436.
18. H. Wang, L.-F. Cui, Y. Yang, H. S. Casalongue, J. T.
Robinson, Y. Liang, Y. Cui, H. Dai, J. Am. Chem. Soc.
2010, 132 13978.
19. G. Yu, L. Hu, M. Vosgueritchian, H. Wang, X.Xie, J. R.
McDonough, X. Cui, Y. Cui, Z. Bao, Nano Lett. 2011, 11,
2905.
20. J. Yan, Z. Fan, T. Wei, W. Qian, M. Zhang, F. Wei, Carbon
2010, 48, 3825.
21. S. Chen, J. Zhu, X. Wu, Q. Han, X.Wang, ACS Nano 2010,
4, 2822.
22. Z.-S. Wu, W. Ren, D.-W. Wang, F. Li, B. Liu, H.-M. Cheng,
ACS Nano 2010, 4, 5835.
23. J. Qu, F. Gao, Q. Zhou, Z. Wang, H. Hu, B. Li, W. Wan, X.
Wang, J. Qiu, Nanoscale 2013, 5 2999.
24. F. Gao,J. Qu,Z. Zhao, Q.Zhou,B. Li,J. Qiu,Carbon 2014,
80, 640.
25. W. S. Hummers Jr, R. E.Offeman, J. Am.Chem.Soc.1958,
80, 1339.
Figure 4. Recycle experiment after treating the catalyst with
aqueous KOH.
26. C. Huang, C. Li, G. Shi, Energy Environ. Sci. 2012, 5,
8848.
27. S. Yamamoto, H. Kinoshita, H. Hashimoto, Y. Nishina,
Nanoscale 2014, 6, 6501.
28. N. Morimoto, S. Yamamoto, Y. Takeuchi, Y. Nishina, RSC
Adv. 2013, 3, 15608.
29. G. Fan, W. Huang, C. Wang, Nanoscale 2013, 5, 6819.
30. Q.-Y. Meng, Q. Liu, J.-J. Zhong, H.-H. Zhang, Z.-J. Li, B.
Chen, C.-H. Tung, L.-Z. Wu, Org. Lett. 2012, 14, 5992.
31. S. K. Movahed, M. Fakharian, M. Dabiri, A. Bazgir, RSC
Adv. 2014, 4, 5243.
32. O. Kamm, C. S. Marvel, R. H. Goshorn, T. Boyd, E. F.
Degering, Org. Synth. 1921, 1, 3.
33. L. H. Smith, Org. Synth. 1943, 23, 88.
34. G.A. Wiley, R. L. Hershkowitz, B. M. Rein, B. C. Chung.
J. Am. Chem. Soc. 1964, 86, 964.
35. J. D. Pelletier, D. Poirier, Tetrahedron Lett. 1994, 35, 1051.
36. N. Iranpoor, H. Firouzabadi, A. Jamalian, F. Kazemi,
Tetrahedron 2005, 61, 5699.
37. C. H. Dai, J. M. R. Narayanam, C. R. J. Stephenson, Nat.
Chem. 2011, 3, 140.
38. G.Egloff, R. E. Schaad,C. D.Lowry,Jr., Chem.Rev.1931,
8, 1.
39. H. Shaw, H. D. Perlmutter, C. Gu, J. Org. Chem. 1997, 62,
236.
40. T. M. Shaikh,A. Sudalai, Tetrahedron Lett. 2005, 46, 5587.
41. R. Montoro, T. Wirth, Synthesis 2005, 1473.
42. X. Jiang, M. Shen, Y. Tang, C. Li, Tetrahedron Lett. 2005,
46, 487.
43. I. S. Akhrem,A. V. Orlinkov, L. V.Afanaseva, E. I. Mysov,
M. E. Volpin, Tetrahedron Lett. 1995, 36, 9365.
44. Y. Nishina, J. Morita, B. Ohtani. RSC Adv. 2013, 3, 2158.
45. J. Qu, L. Shi, C. He, F. Gao, B. Li, Q. Zhou, H. Hu, G.
Shao, X. Wang, J. Qiu, Carbon 2014, 66, 485.
46. Y.Li,J. Qu,F. Gao,S. Lv,L. Shi C.He, J. Sun,Appl.Catal.
B: Environ. 2015, 162, 268.
4. Conclusion
In conclusion, we have successfully developed a facile
preparation method for MnOX/GO composites fromgraphiteand
KMnO4. The MnOX/GO could be applied as a catalyst for direct
bromination ofhydrocarbons. The catalyst could be reused by
treating with aqueous KOH to remove Br fromMn species. GO
could strongly bind with Mn to prevent elution to the liquid
phase; therefore, we expect that the MnOX/GO composite can be
applicable not only in the catalysis, but in a wide range ofareas
such as electrode materials.
Acknowledgement
This work was partly supported by the Nanotechnology
Platform Program, JST PRESTO, JSPS KAKENHI Grant
Number 16H00915.
References
1.
D. R. Dreyer, S. Park, C.W. Bielawski, R. S. Ruoff, Chem.
Soc. Rev. 2010, 39, 228.
S. Eigler,A. Hirsch, Angew. Chem. Int. Ed. 2014, 52, 7720.
X. Huang, X. Qi, F. Boey, H. Zhang, Chem. Soc. Rev. 2012,
41, 666.
S. Stankovich, D. A. Dikin, G. H. B. Dommett, K. M.
Kohlhaas, E. J. Zimney, E. A. Stach, R. D. Piner, S. T.
Nguyen, R. S. Ruoff, Nature 2006, 442, 282.
C.Chung, Y.-K. Kim, D. Shin, S.-R. Ryoo, B. H. Hong, D.-
H. Min, Acc. Chem. Res. 2013, 46, 2211.
Z. Liu, J. T. Robinson, X. Sun, H. Dai, J. Am. Chem. Soc.
2008, 130, 10876.
C. K. Chua, M. Pumera, Chem. Eur. J. 2015, 21, 12550.
R. K. Joshi, S. Alwarappan, M. Yoshimura, V. Sahajwalla,
Y. Nishina, Appl. Mater. Today 2015, 1, 1.
2.
3.
4.
5.
6.
7.
8.
9.
C. K. Chua, M. Pumera, Chem. Soc. Rev. 2013, 42, 3222.
10. C. K. Chua, M. Pumera, Chem. Soc. Rev. 2014, 43, 291.
11. S. Bai, X. Shen, RSC Adv. 2012, 2, 64.
12. Y. Yu, B. Zhang, Y.-B. He, Z.-D. Huang, S.-W. Oh, J.-K.
Kim, J. Mater. Chem. A 2013, 1, 1163.
13. J. W. Lee, A. S. Hall, J.-D. Kim, T. E. Mallouk, Chem.
Mater. 2012, 24, 1158.
47. Based on the XANES analysis, the Mn content was
calculated as Mn+3.0 oxide.
48. A. B. Petersen, I. W. M. Smith, Chem. Phys. 1978, 30, 407.
14. K.-W. Park, J. Mater. Chem. A 2014, 2, 4292.
15. G. G. Kumar, Z. Awan, K. S. Nahm, J. S. Xavier, Biosens.
Bioelectronics 2014, 53, 528.

Graphical Abstract
<Title>
Preparation of manganese/graphite oxide composite using permanganate and graphite: application as catalyst in bromination of
hydrocarbons
<Authors' names>
Hideyuki Suzuki and Yuta Nishina,
<Summary>
Manganese (Mn) /graphite oxide (GO) composites were prepared in one-pot by oxidizing graphite with KMnO4 (Hummers’ method)
and successive treatment with KOH aq. The Mn/GO was applied as a recyclable catalyst for bromination ofhydrocarbons, one ofthe
most basic but important chemical transformations.
<Diagram>