Pt Nanoparticles Loaded on Reduced Graphene Oxide as an Effective
Catalyst for the Direct Oxidation of 5-Hydroxymethylfurfural (HMF)
to Produce 2,5-Furandicarboxylic Acid (FDCA) under Mild Conditions
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Wenqi Niu, Ding Wang, Guohui Yang, Jian Sun, Mingbo Wu,
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Yoshiharu Yoneyama, and Noritatsu Tsubaki*
1Department of Applied Chemistry, School of Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555
2School of Materials Science and Engineering, University of Shanghai for Science and Technology,
Shanghai 200093, P. R. China
3State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao 266580, Shandong, P. R. China
E-mail: tsubaki@eng.u-toyama.ac.jp
Received: April 1, 2014; Accepted: July 9, 2014; Web Released: July 18, 2014
Reduced graphene oxide (RGO) is one of the most promising catalyst supports because it has faintly acidic sites
together with a large amount of functional groups on its surface. In this report, we prove that, for the first time, Pt-loaded
RGO (Pt/RGO) is an efficient, robust, and durable catalyst for oxidizing 5-hydroxymethylfurfural (HMF) directly to 2,5-
furandicarboxylic acid (FDCA) under mild conditions. The selectivity of FDCA reaches up to 84% along with 100% HMF
conversion in the presence of excess base. We deduce that the total reaction on the Pt/RGO catalyst includes several
consecutive steps, in which 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) acts as an intermediate. The finding in this
report is a significant advancement not only for RGO-based catalyst development, but also for scalable FDCA production,
because the total reaction is performed smoothly without using the previously reported harsh reaction conditions.
Nowadays, 5-hydroxymethylfurfural (HMF), a biomass-
derived intermediate, is readily available from a variety of
catalysts seem to be promising, the catalyst design and reaction
conditions, especially reaction temperature and pressure, must
be further optimized.
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renewable biomass resources such as fructose, glucose, poly-
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saccharides, and cellulose. The compound 2,5-furandicarbox-
ylic acid (FDCA) has been considered as a potential biorenew-
able monomer to replace terephthalic acid in the production of
Carbon material, such as activated carbon, has been reported
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0,11,13,1517
as catalyst support in the HMF oxidation reaction.
However, to our knowledge, graphene oxide, a novel carbon
material, has not been reported as a catalyst or support mate-
rial in this reaction until now. Compared with other carbon
materials, graphene oxide has attracted tremendous attention
in recent years due to its relatively stable physical properties
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poly(ethylene terephthalate) (PET). Moreover, FDCA has also
been identified as one of several important building blocks for
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the production of biomass-derived value-added chemicals.
Generally, the oxidation of HMF to FDCA can be catalyzed
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by various stoichiometric oxidants, such as KMnO , or homo-
and unique two-dimensional planar structure. In addition,
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geneous metal salts (Co or Mn), which are currently used for
terephthalic acid production under high pressure (70 bar air).
graphene oxide is slightly acidic since there are a large amount
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of functional groups on its surface.
These functional groups
Different reaction systems using Pt-, Pd-, or Ru-based hetero-
geneous catalysts have been reported for the selective oxidation
of HMF to FDCA, but these methods require high pressure
or high temperature and have lower catalyst stability and
selectivity.
on the surface of graphene oxide can be utilized as anchoring
sites to affix metallic nanoparticles, increasing the dispersion of
the supported nanocatalysts and tuning their catalytic perform-
ance. Moreover, graphene sheets have a spillover effect under a
H or O reaction atmosphere, especially when noble metals
exist as the supported catalyst. These special performances
may be beneficial for the oxidation of HMF when Pt-loaded
reduced graphene oxide (Pt/RGO) is used as catalyst.
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Recently, several reports have been presented using sup-
ported Pt catalysts for aqueous HMF oxidation to improve
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FDCA yields.
reported by Davis et al.,13 the addition of a homogeneous base
120 equiv of NaOH) and high oxygen pressure (320 bar) are
When using the supported Pt as a catalyst, as
In this work, the Pt-loaded reduced graphene oxide (Pt/
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2
(
RGO) catalyst was prepared by ethylene glycol reduction and
used in the HMF oxidation reaction to produce FDCA. Other
metallic nanoparticles, like Pd, Ru, Rh, and Pt, loaded on the
reduced graphene oxide were also prepared and their catalytic
performances were compared. As the best catalyst for FDCA
production, Pt/RGO was investigated in detail. The possible
required. Strasser et al. showed that the feedstock of HMF
degrades rapidly at 353 K in alkaline water.15 In addition, Gupta
et al. also reported a base-free oxidation in water over gold
catalysts supported on hydrotalcites, yielding FDCA with an
almost 100% yield at 368 K.14 Although Pt- and Au-based
© 2014 The Chemical Society of Japan