CHEMSUSCHEM
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DOI: 10.1002/cssc.201300196
Highly Selective Hydrogenolysis of Glycerol to
1,3-Propanediol over a Boehmite-Supported Platinum/
Tungsten Catalyst
Racha Arundhathi,[a] Tomoo Mizugaki,[a] Takato Mitsudome,[a] Koichiro Jitsukawa,[a] and
Kiyotomi Kaneda*[a, b]
Biomass has attracted much attention as a carbon-neutral re-
source with the potential to reduce both the rapid consump-
tion of fossil fuels and the vast quantity of CO2 emissions asso-
ciated to that consumption.[1] Recent increases in the demand
for biodiesel as an alternative fuel have also led to the produc-
tion of large quantities of glycerol, which is generated as a by-
product of the biodiesel manufacturing process. For this
reason, there is currently much interest in developing methods
for the chemical transformation of this abundant feedstock
into value-added chemicals. Among these methods,[2–5] the hy-
drogenolysis of glycerol to 1,3-propanediol (1,3-PDO) is one of
the most promising transformations because 1,3-PDO is
a useful building block in the production of a wide range of
valuable polymers.[6] The production of 1,3-PDO from glycerol
has the potential to serve as a viable alternative to the current
industrial-scale production of 1,3-PDO from petroleum feed-
stocks. Many research groups have explored efficient catalytic
systems for the selective hydrogenolysis of glycerol to
1,3-PDO.[3] The best system reported to date was developed by
Tomishige and co-workers, who described how SiO2-supported
Ir-ReOx nanoparticles (NPs) produce high yields of 1,3-PDO in
aqueous reaction solutions.[3j] Lee and co-workers have also re-
ported the selective synthesis of 1,3-PDO, using sulfated ZrO2-
supported platinum NPs, employing 1,3-dimethyl-2-imidazolidi-
none as solvent.[3d] However, these catalytic systems produced
insufficient yields of 56%, and still required the use of acidic
additives and/or organic solvents, and so the development of
more efficient catalytic systems for the selective conversion of
glycerol to 1,3-PDO remains a challenge.
plays a crucial role in this selective synthesis of 1,3-PDO be-
cause it preferentially combines with the primary OH groups of
glycerol to form Al-alkoxides. This allows the subsequent selec-
tive hydrogenolysis of the unbound secondary OH group of
the glycerol by Pt NPs supported on the WOx, leading to the
synthesis of 1,3-PDO. This finding inspired us to design a new
catalyst consisting of monohydroxy aluminum oxide (boehm-
ite; AlOOH), which has numerous Al-OH groups on its surface,
as a support for Pt NPs and WOx species. Our hypothesis was
that the many Al-OH groups of the boehmite support would
promote the formation of Al-alkoxide species from the primary
OH groups of glycerol, leading to the highly efficient and se-
lective synthesis of 1,3-PDO.
Herein, we report that the newly synthesized boehmite-sup-
ported Pt NPs/WOx material (Pt/WOx/AlOOH) does indeed act
as a highly efficient catalyst for the selective hydrogenolysis of
glycerol to 1,3-PDO in aqueous solution without the use of ad-
ditives. The catalytic activity is superior to that of previously re-
ported catalyst systems. Furthermore, this solid catalyst is re-
coverable and reusable while maintaining its high catalytic ac-
tivity and selectivity.
Pt/WOx/AlOOH was prepared by successive wet-impregna-
tion and calcination, using ammonium (para)tungstate (APT)
and H2PtCl6.[8] The amounts of Pt and W loaded in Pt/WOx/
AlOOH were estimated by elemental analysis to be 1.8 and
8 wt%, respectively, and the Brunauer–Emmett–Teller (BET) sur-
face area of the resulting Pt/WOx/AlOOH was 180 m2gÀ1. The
W L3-edge XANES spectrum of the catalyst was similar to those
of WO3 and ammonium (para)tungstate (Figure S1). The X-ray
diffraction (XRD) patterns of the catalyst did not show any
peaks due to Pt or WOx species, demonstrating that the Pt
NPs and WOx were well-dispersed over the surface of the sup-
port (Figure S2). Transmission electron microscopy (TEM)
images of the material also confirmed that the Pt NPs exhibit-
ed a high degree of dispersion, with a mean diameter of 3 nm
(Figure S3). Two additional Pt/WOx/AlOOH catalysts with differ-
ent surface areas were also prepared, via the same method as
above but using AlOOH with varying surface areas: Pt/WOx/
AlOOH (123 m2 gÀ1) and Pt/WOx/AlOOH (56 m2 gÀ1).
Recently, our group developed a reusable Pt-AlOx/WO3 cata-
lyst for the selective hydrogenolysis of glycerol to 1,3-PDO in
water,[7] with yields greater than those previously reported for
organic-solvent- and additive-free catalyst systems. The AlOx
[a] Dr. R. Arundhathi, Dr. T. Mizugaki, Dr. T. Mitsudome, Prof. Dr. K. Jitsukawa,
Prof. Dr. K. Kaneda
Department of Materials Engineering Science
Graduate School of Engineering Science
Osaka University
1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)
Fax: (+81)6-6850-6260
Pt/WOx/AlOOH samples thus prepared were tested for their
ability to catalyze the hydrogenolysis of glycerol in aqueous
solution at 453 K and under a 5 MPa H2 atmosphere for 12 h.
Notably, Pt/WOx/AlOOH exhibited significant catalytic activity
and selectivity, generating 1,3-PDO in 66% yield following
complete conversion of the glycerol (Table 1, entry 1).[9] Among
the Pt/WOx/AlOOH catalysts having different surface areas, the
[b] Prof. Dr. K. Kaneda
Research Center for Solar Energy Chemistry
Osaka University
1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)
Supporting Information for this article is available on the WWW under
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemSusChem 0000, 00, 2 – 3
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Arundhathi, Racha
