Surface Modification of a Supported Pt Catalyst Using Ionic Liquids for Selective Hydrodeoxygenation of Phenols into Arenes under Mild Conditions

Article abstract of DOI:10.1002/chem.201902668

The selective and efficient removal of oxygenated groups from lignin-derived phenols is a critical challenge to utilize lignin as a source for renewable aromatic chemicals. This report describes how surface modification of a zeolite-supported Pt catalyst using ionic liquids (ILs) remarkably increases selectivity for the hydrodeoxygenation (HDO) of phenols into arenes under mild reaction conditions using atmospheric pressure H₂. Unmodified Pt/H-ZSM-5 converts phenols into aliphatic species as the major products along with a slight amount of arenes (10 % selectivity). In contrast, the catalyst modified with an IL, 1-butyl-3-methylimidazolium triflate, keeps up to 76 % selectivity for arenes even at a nearly complete conversion of phenols. The IL on the surface of Pt catalyst may offer the adsorption of phenols in an edge-to-face manner onto the surface, thus accelerating the HDO without the ring hydrogenation.

Full text of DOI:10.1002/chem.201902668

A Journal of
Accepted Article
Title: Surface Modification of a Supported Pt Catalyst Using Ionic
Liquids for Selective Hydrodeoxygenation of Phenols into Arenes
under Mild Conditions
Authors: Hidetoshi Ohta, Kanako Tobayashi, Akihiro Kuroo, Mao
Nakatsuka, Hirokazu Kobayashi, Atsushi Fukuoka, Go
Hamasaka, Yasuhiro Uozumi, Haruno Murayama, Makoto
Tokunaga, and Minoru Hayashi
This manuscript has been accepted after peer review and appears as an
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the VoR from the journal website shown below when it is published
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content of this Accepted Article.
To be cited as: Chem. Eur. J. 10.1002/chem.201902668
Link to VoR: http://dx.doi.org/10.1002/chem.201902668
Supported by

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COMMUNICATION
Surface Modification of a Supported Pt Catalyst Using Ionic
Liquids for Selective Hydrodeoxygenation of Phenols into Arenes
under Mild Conditions
Hidetoshi Ohta,*[a] Kanako Tobayashi,[a] Akihiro Kuroo,[a] Mao Nakatsuka,[a] Hirokazu Kobayashi,[b]
Atsushi Fukuoka,[b] Go Hamasaka,[c] Yasuhiro Uozumi,[c] Haruno Murayama,[d] Makoto Tokunaga,[d]
Minoru Hayashi*[a]
Abstract: The selective and efficient removal of oxygenated groups
from lignin-derived phenols is a critical challenge to utilize lignin as a
source for renewable aromatic chemicals. This report describes that
surface modification of a zeolite-supported Pt catalyst using ionic
pathway consisted of the ring hydrogenation, the dehydration of
cycloalkanols, and the hydrogenation of cycloalkenes (Scheme
1, path A). However, we found that a small amount of an arene
was formed as a transient product in the early stage of the
reaction. Among the several possible routes for the arene
formation (Scheme S1 in Supporting Information), we assumed
that the arene was obtained through the partial hydrogenation-
dehydration pathway (Scheme 1, path B). The resulting arene
was eventually reduced to the corresponding cyclohexane.
These results demonstrate that the catalyst can convert phenols
to arenes under the mild conditions but does not show selectivity
toward arenes.
liquids
(ILs)
remarkably
increases
selectivity
for
the
hydrodeoxygenation (HDO) of phenols into arenes under mild
reaction conditions using atmospheric pressure H2. Unmodified Pt/H-
ZSM-5 converts phenols into aliphatic species as the major products
along with a slight amount of arenes (10% selectivity). In contrast,
the catalyst modified with an IL, 1-butyl-3-methylimidazolium triflate,
keeps up to 76% selectivity for arenes even at a nearly complete
conversion of phenols. The IL on the surface of Pt catalyst may offer
the adsorption of phenols in an edge-to-face manner onto the
surface, thus accelerating the HDO without the ring hydrogenation.
Development of a catalytic process to convert lignin into
aromatic fundamental chemicals has emerged as an important
challenge to establish biorefinery-based industries.1 Lignin is a
three-dimensional aromatic polymer contained in lignocellulosic
biomass, and the lignin-first approach using acids and metal
catalysts efficiently converts lignocellulose to phenols.1a,2
Hydrodeoxygenation (HDO) of the phenols produces arenes that
can alternate petrol-based aromatics.3 However, the HDO
reaction suffers from harsh reaction conditions (generally 300 °C
or higher under pressurized H2) and low selectivity for arenes
due to the complete hydrogenation to cycloalkanes.3,4 Even after
recent mechanistic studies on the HDO pathways to show
directions to the catalyst design for the selective arene
production,3,5 they have remained serious issues.
Scheme 1. Proposed reaction pathways for the HDO of phenols by IL-
modified and unmodified Pt/H-ZSM-5.
We previously reported the selective HDO of phenols into
cycloalkanes using
a
metal-acid bifunctional Pt/H-ZSM-5
catalyst in octane at 110 °C under atmospheric pressure H2.6
The time course of this reaction indicated that a major reaction
[a]
Dr. H. Ohta, K. Tobayashi, A. Kuroo, M. Nakatsuka, Dr. M. Hayashi
Department of Materials Science and Biotechnology, Graduate
School of Science and Engineering, Ehime University
3 Bunkyo-cho, Matsuyama 790-8577 (Japan)
E-mail: ota.hidetoshi.mx@ehime-u.ac.jp (Ohta); mhayashi@ehime-
u.ac.jp (Hayashi)
[b]
[c]
[d]
Dr. H. Kobayashi, Prof. Dr. A. Fukuoka
Institute for Catalysis, Hokkaido University
Kita 21 Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0021 (Japan)
Dr. G. Hamasaka, Prof. Dr. Y. Uozumi
Institute for Molecular Science
Myodaiji, Okazaki 444-8787 (Japan)
Dr. H. Murayama, Prof. Dr. M. Tokunaga
Department of Chemistry, Faculty of Science, Graduate School of
Kyushu University
Figure 1. Presumed adsorption modes of phenols onto a metal surface
forming (a) aliphatics and (b) arenes. (c) Schematic images expected for the
surface structure of IL-modified Pt/H-ZSM-5 in the HDO of phenols.
In the present study, we aimed for the selective conversion
of phenols to arenes (path B) by modifying surface properties of
the Pt/H-ZSM-5 catalyst, thereby achieving the arene-selective
HDO under mild conditions at 110 °C with atmospheric pressure
H2. Control of the adsorption mode of phenols onto a metal
744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)
Supporting information for this article is given via a link at the end of
the document.
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surface may be crucial to improve the selectivity of arenes. Thus,
the adsorption of the aromatic ring parallel to a metal surface
would promote the formation of aliphatics, whereas the vertical
and tilted adsorption may facilitate the partial hydrogenation and
finally give arenes (Figure 1, a and b).7 In addition, the reduction
in hydrogenation activity of the metal and the concentration of
surface hydrogen species would be effective to suppress the
excessive hydrogenation.8 In order to control these factors, we
performed the surface modification of Pt/H-ZSM-5 using ILs. It is
known that ILs form an ordered structure on a metal surface9
and their physical properties such as viscosity and gas solubility
can be regulated by the cation-anion combination.10 Figure 1c
shows the schematic image expected for the surface structure of
IL-modified Pt/H-ZSM-5 (denoted as IL/Pt/H-ZSM-5) in the HDO
of phenols. Here, the ILs would decrease the hydrogenation
activity and the hydrogen concentration by occupying the Pt
surface.11 Furthermore, the loosely ordered ILs on the Pt surface
may affect the adsorption mode of phenols.12 On the basis of the
hypotheses, we investigated the HDO of phenols using IL/Pt/H-
ZSM-5 catalysts.
The surface modification of 5 wt% Pt/H-ZSM-5 catalyst was
performed by impregnating with various ILs in dry MeOH
followed by evaporation and drying under vacuum. The prepared
catalysts were characterized by several analytical methods, the
details of which are available in Supporting Information.
Selected analytical data of 30 wt% 1-butyl-3-methylimidazolium
triflate ([bmim][OTf])-modified and unmodified Pt/H-ZSM-5 are
shown in Figure 2. The 13C{1H} NMR spectra showed that
[bmim][OTf] existed on the catalyst surface and remained intact
after modification (Figure 2a). In XRD analysis, the modification
of Pt/H-ZSM-5 with [bmim][OTf] reduced the intensity of the
diffraction peaks at 2θ = 7° to 18°, which include the (020) and
(200) planes related to the 10-membered ring channel directions
of H-ZSM-5 (Figure 2b).13 It is suggested that a part of
[bmim][OTf] was located within the pores.14 A large decrease in
the BET surface area and the pore volume determined by N2
adsorption measurements after the modification (Table S1) is
consistent with the XRD results. TEM analysis confirmed that
the average Pt particle size of Pt/H-ZSM-5 did not change by the
modification (Figure 2c), whereas the CO adsorption
measurements showed that the CO-accessible Pt surface area
of Pt/H-ZSM-5 decreased to 16% of the original value (Table S1).
These data show that [bmim][OTf] covers Pt surface. In Pt LIII-
edge XAFS analysis, [bmim][OTf]-modified and unmodified Pt/H-
ZSM-5 provided slightly larger white lines than that of Pt foil in
the XANES spectra (Figure 2d). This result shows lower electron
density on 5d orbitals due to the + oxidation state.15 The
average Pt oxidation state in [bmim][OTf]-modified and
unmodified Pt/H-ZSM-5 was evaluated in detail by Pt LI-edge
XAFS analysis and determined to be 0.44 and 0.56, respectively
(Figures S2 and S3).16
Figure 2. (a) 13C{1H} NMR spectra of 30 wt% [bmim][OTf]/Pt/H-ZSM-5 (solid-
state CP/MAS) and [bmim][OTf] (solution-state, in CDCl3). (b) XRD patterns as
well as (c) TEM images and Pt particle size distributions of 5 wt% Pt/H-ZSM-5
and 30 wt% [bmim][OTf]/Pt/H-ZSM-5. (d) Pt LIII-edge XANES spectra of PtO2,
5 wt% Pt/H-ZSM-5, 30 wt% [bmim][OTf]/Pt/H-ZSM-5, and Pt foil.
Effect of ILs-modification of Pt/H-ZSM-5 was evaluated in
the HDO of 4-propylphenol 1 in octane at 110 °C under
atmospheric pressure H2 (Table 1). As shown in entry 1,
unmodified Pt/H-ZSM-5 gave aliphatics 3 − 5 as the major
products and desired arene 2 in 10% selectivity. Bare Pt/H-ZSM-
5 was useless for the production of arenes, and thus we
performed the HDO using Pt/H-ZSM-5 modified with 30 wt%
[bmim]+-based ILs having different anions. The ILs having [Cl]-,
[PF6]-, [BF4]-, and [BArF]- anions just decreased the
hydrogenation activity with no improvement on the selectivity for
2 (entries 2 − 5). In contrast, [NTf2]-, [NPf2]-, [CPFSA]-, [OTf]-,
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and [ONf]- anions improved the selectivity for 2 (entries 6 − 10).
The highest selectivity was obtained by the catalyst having [OTf]-
anion. In addition, the HDO using the catalysts modified with ILs
having other cations gave 2 in lower selectivity (Table S2). The
increase in the loading amount of [bmim][OTf] from 30 wt% to 50
attributed to the molecular planarity.18 We propose that a planar
phenol can penetrate into the ordered structure of ILs on the
surface of Pt and undergoes selective hydrogenation in the
edge-to-face form. Non-planar bulky substituents cannot
preserve the ordered structure of ILs in the adsorption and
therefore leads to the hydrogenation to cycloalkanes. Next, we
studied the effect of o-substitution of phenols on the HDO
reaction. 2-t-Butyl-4-methylphenol 12 required a significantly
longer reaction time (8 h, 24% conversion) for the HDO reaction
than that for 1 (2 h, 94% conversion), and the arene selectivity
was moderate as expected in the above discussion. Besides,
the o-substitution with methyl groups 14 and 16, possessing
good molecular planarity, also decreased the conversion rate of
the substrate but maintained good selectivity (6574%). The
effect of the steric hindrance indicates that the HDO reaction
requires the hydrogenation of phenolic hydroxyl groups or C=C
double bond near from the OH groups, which supports the
reaction path B in Scheme 1. Finally, we tested an alkyl guaiacol
18, an important lignin-related phenol, provided 69% conversion
after 12 h and gave fully-deoxygenated 2, monodeoxygenated
19 and 1 in selectivity of 44%, 7%, and <1%, respectively. This
selectivity is not very high but one of the highest ever reported
among the HDO using molecular H2 in spite of the much lower
temperature (110 C) than those in the previous reports (300 C
or higher).3a This is surprising as the formation of arenes are
thermodynamically favored at higher temperatures. The HDO by
[bmim][OTf]/Pt/H-ZSM-5 still requires further improvement in
substrate scope and arene selectivity.19 However, the catalyst
design concept shown in this study would be informative for
future development of the HDO under mild conditions.
wt% improved the selectivity for
2 to 71% (entry 11).
Furthermore, nearly complete conversion (94%) was obtained
after a two-hour reaction with keeping a good selectivity (76%)
for 2, achieving the highest yield in this study (72%) (entry 12).
The use of higher amounts of ILs reduces the reaction rate; in
the extreme case, the reaction using Pt/H-ZSM-5 catalyst and
[bmim][OTf] as a solvent did not afford any products (Table S2).
Thus, 50 wt% [bmim][OTf]/Pt/H-ZSM-5 is the best catalyst for
the HDO of 1 under the mild reaction conditions.17
Table 1. HDO of 4-propylphenol 1 by IL/Pt/H-ZSM-5.[a]
Conversion
[%]
Selectivity [%]
Entry
IL
2
3
4
5
1
None
86
7
10
6
17
3
9
57
1
2
[bmim][Cl]
4
3
[bmim][PF6]
[bmim][BF4]
[bmim][BArF]
[bmim][NTf2]
[bmim][NPf2]
[bmim][CPFSA]
[bmim][OTf]
[bmim][ONf]
[bmim][OTf]
[bmim][OTf]
19
9
11
8
4
19
26
0
15
2
4
6
5
49
61
51
38
61
61
66
94
9
8
65
2
Table 2. HDO of various phenols.[a]
6
37
45
50
56
37
71
76
35
35
16
18
23
10
12
2
7
2
0
8
0
3
9
4
2
10
11[b]
12[b,c]
4
1
0
6
6
3
[a] Reaction conditions: 1 (1.0 mmol), 30 wt% IL/Pt/H-ZSM-5 (1 mol% Pt),
octane (1 mL), 110 °C, H2 (balloon, 1 atm), 1 h. [b] 50 wt% [bmim][OTf]/Pt/H-
ZSM-5 (1 mol% Pt) was used. [c] The reaction was conducted for 2 h.
The catalytic property of 50 wt% [bmim][OTf]/Pt/H-ZSM-5
was investigated by using various substituted phenols in the
HDO (Table 2). Among the p-substituted phenols, the increase
in the bulkiness of the alkyl moiety from n-propyl (1) to i-propyl
(6), t-butyl (8), and n-heptyl (10) groups decreased selectivity for
the corresponding arenes under the same reaction conditions.
The reaction rate was only slightly decreased in these cases.
The higher selectivity for less bulky substituents may be
[a] Reaction conditions: phenols (1.0 mmol), 50 wt% [bmim][OTf]/Pt/H-ZSM-5
(1 mol% Pt), octane (1 mL), 110 °C, H2 (balloon, 1 atm).
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[1]
For reviews, see: a) Z. Sun, B. Fridrich, A. de Santi, S. Elangovan, K.
Barta, Chem. Rev. 2018, 118, 614-678; b) C. Li, X. Zhao, A. Wang, G.
W. Huber, T. Zhang, Chem. Rev. 2015, 115, 11559-11624; c) J.
Zakzeski, P. C. A. Bruijnincx, A. L. Jongerius, B. M. Weckhuysen,
Chem. Rev. 2010, 110, 3552-3599.
We hypothesize that the HDO of phenols into arenes
catalyzed by [bmim][OTf]/Pt/H-ZSM-5 proceeds through path B
shown in Scheme 1. As discussed in the introduction part, there
are several possibility for the HDO pathway. The most often
found mechanism is the hydrogenation of phenols to
cycloalkanols followed by the dehydration and the
dehydrogenation (Scheme S1).3,5c,5h Therefore, we performed
the control experiment using 4-propylcyclohexanol 5 as a
substrate (Scheme 2) to reveal whether the HDO by
[bmim][OTf]/Pt/H-ZSM-5 proceeded through the pathway. As a
result, our catalyst did not give 2 at all, thus indicating that the
path B is more plausible for the HDO by [bmim][OTf]/Pt/H-ZSM-5.
[2]
[3]
[4]
a) T. Renders, S. Van den Bosch, S.-F. Koelewijn, W. Schutyser, B. F.
Sels, Energy Environ. Sci. 2017, 10, 1551-1557; b) M. D. Kärkäs,
ChemSusChem 2017, 10, 2111-2115.
For reviews, see: a) A. M. Robinson, J. E. Hensley, J. W. Medlin, ACS
Catal. 2016, 6, 5026-5043; b) D. A. Ruddy, J. A. Schaidle, J. R. Ferrell
III, J. Wang, L. Moens, J. E. Hensley, Green Chem. 2014, 16, 454-490.
Selected recent papers about the HDO of phenols into arenes: a) P. M.
de Souza, R. C. Rabelo-Neto, L. E. P. Borges, G. Jacobs, B. H. Davis,
U. M. Graham, D. E. Resasco, F. B. Noronha, ACS Catal. 2015, 5,
7385-7398; b) C. Chen, G. Chen, F. Yang, H. Wang, J. Han, Q. Ge, X.
Zhu, Chem. Eng. Sci. 2015, 135, 145-154; c) X. Zhu, L. Nie, L. L.
Lobban, R. G. Mallinson, D. E. Resasco, Energy Fuels 2014, 28, 4104-
4111; d) J. Sun, A. M. Karim, H. Zhang, L. Kovarik, X. S. Li, A. J.
Hensley, J.-S. McEwen, Y. Wang, J. Catal. 2013, 306, 47-57; e) A. L.
Jongerius, R. Jastrzebski, P. C. A. Bruijnincx, B. M. Weckhuysen, J.
Catal. 2012, 285, 315-323.
[5]
a) C. Wang, A. V. Mironenko, A. Raizada, T. Chen, X. Mao, A.
Padmanabhan, D. G. Vlachos, R. J. Gorte, J. M. Vohs, ACS Catal.
2018, 8, 7749-7759; b) N. Duong, Q. Tan, D. E. Resasco, C. R. Chimie
2018, 21, 155-163; c) J. Zhang, L. D. Ellis, B. Wang, M. J. Dzara, C.
Sievers, S. Pylypenko, E. Nikolla, J. W. Medlin, Nat. Catal. 2018, 1,
148-155; d) Y. Shao, Q. Xia, L. Dong, X. Liu, X. Han, S. F. Parker, Y.
Cheng, L. L. Daemen, A. J. Ramirez-Cuesta, S. Yang, Y. Wang, Nat.
Commun. 2017, 8, 16104-16112; e) Z. Luo, Z. Zheng, Y. Wang, G. Sun,
H. Jiang, C. Zhao, Green Chem. 2016, 18, 5845-5858; f) Q. Tan, G.
Wang, L. Nie, A. Dinse, C. Buda, J. Shabaker, D. E. Resasco, ACS
Catal. 2015, 5, 6271-6283; g) S. Kusumoto, K. Nozaki, Nat. Commun.
2015, 6, 6296-6302; h) X. Wang, R. Rinaldi, Angew. Chem. Int. Ed.
2013, 52, 11499-11503; i) P. T. M. Do, A. J. Foster, J. Chen, R. F. Lobo,
Green Chem. 2012, 14, 1388-1397.
Scheme 2. A control experiment for elucidation of reaction pathways.
In summary, we developed the selective HDO of phenols
into arenes at 110 °C under atmospheric pressure H2 by a
[bmim][OTf]-modified Pt/H-ZSM-5 catalyst. Unmodified catalyst
gave aliphatic species as the major products, whereas the
modified one afforded arenes up to 72% yield and 76%
selectivity. The type of ILs used for the surface modification
greatly affected the reaction progress and product distributions.
Although the reaction mechanism is still not clear, we consider
that the HDO by [bmim][OTf]/Pt/H-ZSM-5 proceeded through
path B shown in Scheme 1. The control of the adsorption mode
of phenols onto the catalyst surface and the concentration of
surface hydrogen species may be crucial for obtaining high
arene selectivity. The detailed mechanistic studies and the
development of new catalysts based on the catalyst design
concept obtained from this study are currently underway.
[6]
[7]
H. Ohta, K. Yamamoto, M. Hayashi, G. Hamasaka, Y. Uozumi, Y.
Watanabe, Chem. Commun. 2015, 51, 17000-17003.
a) J. Engelhardt, P. Lyu, P. Nachtigall, F. Schüth, Á. M. García,
ChemCatChem 2017, 9, 1985-1991; b) H. Wan, R. V. Chaudhari, B.
Subramaniam, Top Catal. 2012, 55, 129-139; c) Y. Romero, F. Richard,
S. Brunet, Appl. Catal. B: Environ. 2010, 98, 213-223; d) E.-J. Shin, M.
A. Keane, Ind. Eng. Chem. Res. 2000, 39, 883-892; e) G. Neri, A. M.
Visco, A. Donato, C. Milone, M. Malentacchi, G. Gubitosa, Appl. Catal.
A: Gen. 1994, 110, 49-59.
[8]
[9]
Z. Luo, C. Zhao, Catal. Sci. Technol. 2016, 6, 3476-3484.
a) R. Hayes, G. G. Warr, R. Atkin, Chem. Rev. 2015, 115, 6357-6426;
b) W. Zhou, S. Inoue, T. Iwahashi, K. Kanai, K. Seki, T. Miyamae, D.
Kim, Y. Katayama, Y. Ouchi, Electrochem. Commun. 2010, 12, 672-
675; c) L. Leclercq, A. R. Schmitzer, Supramol. Chem. 2009, 21, 245-
263.
Acknowledgements
This work was supported by JSPS KAKENHI (grant number
JP17K14863) and the Cooperative Research Program of
Institute for Catalysis, Hokkaido University (grant numbers
16B1014). We thank the Divisions of Applied Protein Research
and Material Science of the Advanced Research Support Center
(ADRES), Ehime University for MS and NMR measurements.
The XAFS experiments were performed at the BL14B2 beamline
of SPring-8 with the approval of the Japan Synchrotron
Radiation Institute (JASRI), proposal Nos. 2017A1576 and
2018A1736.
[10] a) Z. Lei, C. Dai, B. Chen, Chem. Rev. 2014, 114, 1289-1326; b) J. O.
Valderrama, W. W. Sanga, J. A. Lazzús, Ind. Eng. Chem. Res. 2008,
47, 1318-1330.
[11] a) O. Brummel, F. Faisal, T. Bauer, K. Pohako-Esko, P. Wasserscheid,
J. Libuda, Electrochim. Acta 2016, 188, 825-836; b) J. Arras, E. Paki, C.
Roth, J. Radnik, M. Lucas, P. Claus, J. Phys. Chem. C 2010, 114,
10520-10526; c) J. Arras, M. Steffan, Y. Shayeghi, D. Ruppert, P.
Claus, Green Chem. 2009, 11, 716-723; d) C. W. Scheeren, G.
Machado, S. R. Teixeira, J. Morais, J. B. Domingos, J. Dupont, J. Phys.
Chem. B 2006, 110, 13011-13020.
[12] C. A. Schoenbaum, D. K. Schwartz, J. W. Medlin, Acc. Chem. Res.
2014, 47, 1438-1445.
Keywords: hydrodeoxygenation • phenols • arenes • ionic liquid
[13] M. M. J. Treacy, J. B. Higgins, Collection of Simulated XRD Powder
Patterns for Zeolites, 5th ed., Elsevier, Amsterdam, 2007.
• platinum
[14] a) P. He, Y. Lou, H. Song, Fuel 2016, 182, 577-587; b) H. Wen, Y.
Zhou, J. Xie, Z. Long, W. Zhang, J. Wang, RSC Adv. 2014, 4, 49647-
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49654; c) M. Milanesio, G. Artioli, A. F. Gualtieri, L. Palin, C. Lamberti,
J. Am. Chem. Soc. 2003, 125, 14549-14558.
[18] J. D. Holbrey, W. M. Reichert, M. Nieuwenhuyzen, O. Sheppard, C.
Hardacre, R. D. Rogers, Chem. Commun. 2003, 476-477.
[15] a) Y. Yazawa, H. Yoshida, T. Hattori, Appl. Catal. A: Gen. 2002, 237,
139-148; b) A. N. Mansour, J. W. Cook Jr., D. E. Sayers, J. Phys.
Chem. 1984, 88, 2330-2334.
[19] The reaction of 4’-hydroxypropiophenone, a phenol containing carbonyl
group, was also examined under the conditions shown in Table 2. As a
result, full conversion was achieved after 8 h. However, the reaction
gave low yields of HDO products (2 in 3% and 1 in 7%) along with a
mixture of unidentifiable products. The presence of the carbonyl group
may have caused undesired side reactions.
[16] T. Yamamoto, A. Yukumoto, Bunseki Kagaku 2013, 6, 555-563.
[17] This catalyst system does not selectively provide arenes under
pressurized H2. As shown in the Supporting Information (Table S2,
entry S7), the reaction of 1 under 10 atm H2 gave aliphatic alcohol 5 as
a predominant product.
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Entry for the Table of Contents (Please choose one layout)
Layout 1:
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Surface modification of a zeolite-
supported Pt catalyst using ionic
liquids enabled the selective
hydrodeoxygenation of phenols into
arenes at 110 °C under atmospheric
pressure H2, which are extremely
milder reaction conditions than those
generally used (300 °C or higher
under pressurized H2).
Hidetoshi Ohta,* Kanako Tobayashi,
Akihiro Kuroo, Mao Nakatsuka, Hirokazu
Kobayashi, Atsushi Fukuoka, Go
Hamasaka, Yasuhiro Uozumi, Haruno
Murayama, Makoto Tokunaga, Minoru
Hayashi*
Page No. – Page No.
Surface Modification of a Supported
Pt Catalyst Using Ionic Liquids for
Selective Hydrodeoxygenation of
Phenols into Arenes under Mild
Conditions
Layout 2:
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