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these substrates, n-hexane, n-pentane, 2-methylbutane, 1-hexanol,
1-pentanol, 2-pentanol, 1,6-hexanediol, 1,2-hexanediol, 1,5-penta-
nediol, 1,2-pentanediol, tetrahydropyran, and 2-methyltetrahydro-
furan were purchased from Wako Pure Chemical Industries, Ltd.,
2-hexanol, 3-hexanol, 1,5-hexanediol, 1,4-pentanediol, and 2,4-pen-
tanediol were purchased from Sigma Aldrich, Co., 3-pentanol was
purchased from Tokyo Chemical Industry Co., Ltd., and 2,3-penta-
nediol was synthesized from 2,3-pentanedione (Tokyo Chemical In-
dustry Co., Ltd.) by hydrogenation with Ru/C (Ru 5 wt%, Wako
Pure Chemical Industries, Ltd.).
In the hydrogenolysis of erythritol, glycerol, pentanediols, and pen-
tanols, the mass balance was always in the range of the experi-
mental error (ꢅ5%). The reuse experiments for cellobiose hydroge-
nolysis were performed without separation of the aqueous phase
and catalyst as described below: the reaction was tested at 433 K
and with a large amount of catalyst (0.3 g) and H-ZSM-5 (0.12 g) to
obtain the highest yield in a short time (24 h). After the reaction,
almost all the products were collected in the organic phase and
gas phase, and less than 1% C of cyclic ether products were in the
aqueous phase. After 24 h, the autoclave was cooled in water and
then in dry ice/acetone. In this treatment, both the aqueous and
organic phases were cooled to the solid state. The products in the
organic phase were removed to a glass vial as the organic phase
melted while the aqueous phase was still frozen. Fresh cellobiose
substrate and n-dodecane solvent were added to the reactor. After
three reactions at 433 K, a forth reaction was carried out at 413 K
for 21 h. The fifth usage was performed at 413 K for 60 h (catalyst
(0.15 g), H-ZSM-5 (0.06 g)) after the used catalyst was calcined
(773 K, 3 h) and reduced (8 MPa H2, 473 K, 1 h, water).
Activity tests
Activity tests for the hydrogenolysis of sorbitol were performed in
a 190 mL stainless-steel autoclave with an inserted glass vessel.
Ir-ReOx/SiO2 and H-ZSM-5 were put into an autoclave together
with a stirrer and water (4 g) and heated at 473 K under H2 (8 MPa)
for 1 h for the reduction pretreatment. After the pretreatment, the
autoclave was cooled and H2 was removed. Sorbitol (Wako Pure
Chemical Industries, Ltd., 98%) and n-dodecane (4 mL; Wako Pure
Chemical Industries, Ltd., 99%) were put into the autoclave. The
addition of n-dodecane was effective to keep the mass balance by
capturing the light alkanes produced. After sealing the reactor, the
air was purged by flushing three times with H2 (1 MPa, 99.99%;
Nippon Peroxide Co., Ltd.). The autoclave was heated to reaction
temperature and pressurized to 1 MPa. The temperature was
monitored by using a thermocouple inserted into the autoclave.
On reaching the reaction temperature, the H2 pressure was in-
creased to 8 MPa. During the experiment, the stirring rate was
fixed at 200 rpm (magnetic stirring). The activity tests for Rh-ReOx/
SiO2were performed in the same way as Ir-ReOx/SiO2 except for the
absence of reduction pretreatments at 473 K. The reaction condi-
tions are described for each result. After an appropriate reaction
time, the reactor was cooled in water and then dry ice/acetone,
and the gases were collected in a gas bag. The reaction mixture
was separated into organic and aqueous phases. These two phases
and the catalysts were transferred to a vial. The aqueous phase
was analyzed by using HPLC (Shimadzu LC-10A) with a refractive
index detector (RID) and SUGAR SH1011 column and GC equipped
with a flame ionization detector (FID). The organic phase was ana-
lyzed by using a GC (Shimadzu GC-2014 or GC-2025). A TC-WAX
(diameter 0.25 mmf, 30 m), a Rtx-1-PONA (diameter 0.25 mmf,
100 m), a CP-Sil5 (diameter 0.25 mmf, 50 m), or a Porapak N
column (5 mmf, 2 m) was used for the product separation. The
products were also identified by using GC–MS (QP5050, Shimadzu).
The products of the sorbitol hydrogenolysis were hexanes (such as
n-hexane, 2-methylpentane, and 3-methylpentane), hexanols (such
as 1-hexanol, 2-hexanol, and 3-hexanol), hexanediols (such as 1,6-
hexanediol, 1,2-hexanediol, and 1,5-hexanediol), cyclic ethers (such
as 2,5-dimethyltetrahydrofuran), CꢀC cracking products (such as
n-pentane, n-butane, propane, ethane, and methane), and other
products that could not be identified. The conversion and yield
were calculated on carbon basis and are defined as follows
[Eqs. (8)–(10)]:
Acknowledgements
This work was supported by the JSPS KAKENHI 23760737 and
a part of this research is funded by the Cabinet Office, Govern-
ment of Japan through its “Funding Program for Next Generation
World-Leading Researchers”.
Keywords: alcohols · alkanes · biomass · hydrogenation ·
zeolites
mol of reactant after reaction
ð8Þ
ð9Þ
Conversion ½% Cꢃ ¼
ꢄ 100 %
ꢄ 100
mol of reactant charged
[4] a) M. Pagliaro, R. Ciriminna, H. Kimura, M. Rossi, C. D. Pin, Angew. Chem.
Mi Lee, M. K. Tiwari, J. S. Kim, P. Gunasekaran, S. Y. Kim, I. W. Kim, J. K.
molproduct ꢄ C atoms in product
Yield ½% Cꢃ ¼
molreactant charged ꢄ C atoms in reactant
Yield of unidentified products ½% Cꢃ ¼ Conversionꢀ
X
ð10Þ
molproduct ꢄ C atoms in product
ꢄ 100 %
molreactant charged ꢄ C atoms in reactant
The mass balance of the total products was in the range of the ex-
perimental error (ꢅ5%) at longer reaction times even if hexane-
diols were completely converted. The hydrogenolysis of glucose
(Wako Pure Chemical Industries, Ltd., 98%), cellobiose (MP Bio-
medicals, Inc., 99%), and xylitol (Wako Pure Chemical Industries,
Ltd., 98%) was tested similarly to that of sorbitol. The hydrogenol-
ysis of erythritol and glycerol was also tested in a similar way to
that of sorbitol except without addition of n-dodecane. The hydro-
genolysis of pentanols (1-, 2-, and 3-pentanol) and pentanediols
(1,5-, 1,2-, 1,4-, 2,4-, and 2,3-pentanediol) was also tested in a similar
way to that of sorbitol. Of the products of the hydrogenolysis of
5404; b) S. Sꢂ, H. Silva, L. Brand¼o, J. M. Sousa, A. Mendes, Appl. Catal. B
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemSusChem 2013, 6, 613 – 621 620