Conversion of levulinic acid to γ-valerolactone over ultra-thin TiO2 nanosheets decorated with ultrasmall Ru nanoparticle catalysts under mild conditions

Article abstract of DOI:10.1039/c8gc03529f

Herein, we demonstrate that quantum-sized Ru dot decorated ultra-thin anatase TiO₂ nanosheets with exposed (001) facets could exhibit highly efficient catalytic activity during the conversion of levulinic acid to γ-valerolactone at room temperature. The support effect has been largely attributed to the high energy of TiO₂ (001) which can lead to a stronger interaction between the support and the metal. The surface of Ru/TiO₂-n contains more Ru(0) and results in higher activity and selectivity.

Full text of DOI:10.1039/c8gc03529f

View Article Online
View Journal
Green
Chemistry
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: S. Li, Y. Wang, Y.
Yang, B. Chen, J. Tai, H. Liu and B. Han, Green Chem., 2019, DOI: 10.1039/C8GC03529F.
Volume 18 Number
7
7
April 2016 Pages 1821–2242
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Green
Chemistry
Cutting-edge research for a greener sustainable future
www.rsc.org/greenchem
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1463-9262
CRITICAL REVIEW
G. Chatel et al.
Heterogeneous catalytic oxidation for lignin valorization into valuable
chemicals: what results? What limitations? What trends?
rsc.li/green-chem

Please do not adjust margins
Page 1 of 6
Green Chemistry
View Article Online
DOI: 10.1039/C8GC03529F
Journal Name
COMMUNICATION
Conversion of levulinic acid to γ-valerolactone over ultra-thin TiO2
nanosheets decorated with ultrasmall Ru nanoparticle catalysts
under mild condition
rReceived 00th January 20xx,
Accepted 00th January 20xx
DOI:
1
0.1039/x0xx00000xwww.rsc.org/
ab
ab
ab
a
c
*ab
Shaopeng Li, Yanyan Wang, Youdi Yang, Bingfeng Chen, Jing Tai, Huizhen Liu and Buxing
Han
*ab
Herein, we demonstrate that quantum-sized Ru dots decorated chemical properties, low toxicity and safe storage performance.
1
5-20
ultra-thin anatase TiO
could exhibit the highly efficient catalytic activity for levulinic acid
to γ-valerolactone at room temperature. The support effect has studied widely. Ruthenium is considered as alternative active
been largely attributed to the high energy of TiO
(001) which lead species for this process because of its good hydrogenation
to stronger interaction between the support and the metal. The
surface of Ru/TiO -n contains more Ru (0) and result in higher
2
nanosheets with exposed (001) facets
The selective hydrogenation of LA to GVL has been
2
2
1-25
activity to the carbonyl compounds of aliphatic group.
On
account that the nature of the support could affect the
catalytic performance of the supported metal catalyst, the
2
activity and selectivity.
2 2 3
selective hydrogenation of LA to GVL over SiO , Al O , active
carbon and graphene supported Ru catalysts has been
The nature of the support is very important for the
supported metal catalysts. It has been widely recognized that
the type of support could greatly affect the activity of the
2
6-29
reported.
influence of the support on catalyst selectivity and stability
including Nb , TiO and H-ZSM5. The Ru/TiO gave excellent
selectivity to γ-valerolactone (GVL) (97.5%) at 100% conversion
The groups of Bert M. Weckhuysen checked the
supported catalyst.1-6 In recent years, it has been found that
the activity and selectivity of the catalyst can also be affected
O
2 5
2
2
3
0
7
-9
at 473K. The groups of A. M. Ruppert investigated that the
influence of different types of TiO supports for ruthenium
by the same metal oxide support of different crystal forms.
2
Nowadays, due to the large-scale use of fossil resources,
the global warming problems such as air pollution and energy
shortage become the world focus of constant attention.
Therefore, the development of green renewable energy has
catalysts on the hydrogenation of levulinic acid towards γ-
7
valerolactone. They emphasize that the different electronic
and surface properties of rutile and anatase can strongly affect
the morphology and the activity of the catalysts.
1
0-13
become the focus of future research.
Biomass is the only
It has been reported that the (001) surface of anatase TiO
has higher surface energy (0.90 J/m ) than the other surface.
2
renewable organic carbon resource in nature, which can be
converted into fuel and chemical by biological transformation
or chemical transformation, and thus partially replace fossil
resources. Levulinic acid (LA) is one of the 12 most important
2
31-
3
4
It is possible to change the activity of Ru/TiO
different faces of TiO
2
by exposing
. However, there have been no reports
2
about the effect of different faces of support on the
performance of the catalyst for the selective hydrogenation of
LA to GVL.
platform compounds screened by the U.S. department of
energy.14 LA can be converted into a variety of high value-
added derivatives, such as γ-valerolactone (GVL), angelica
lactone (AI), 4-hydroxypentanoic acid (HPA), 1,4-pentanediol
In this work, we prepared anatase-phase TiO2 with
different shapes including TiO2 octahedron(TiO -o), TiO
(PD) and methyltetrahydrofuran (MTHF).
2
2
decanedron(TiO
activity of Ru/TiO
investigated for the selective hydrogenation of LA to GVL, and
found that Ru/TiO -n exhibited the best catalytic performance.
The yield of GVL can reach 99% at room temperature after 8 h
over Ru/TiO -n.
2
-d) and TiO
2
nanosheet(TiO
2
-n). The catalytic
GVL can be used as fuel additives, food ingredients,
2
-o, Ru/TiO
2
-d and Ru/TiO
2
-n was
pharmaceutical intermediates, high-grade olefin green
renewable fuels, solvents, nylon intermediates and other
commercial purposes because of its excellent physical and
2
2
aBeijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid and
Interface and Thermodynamics Institute of Chemistry, Chinese Academy of Sciences
Beijing 100190 (P.R. China) E-mail:liuhz@iccas.ac.cn, hanbx@iccas.ac.cn
University of Chinese Academy of Sciences, Beijing 100049, P. R. China
Testing and Analysis Center, Institute of Chemistry, Chinese Academy of Sciences
b
c
Beijing 100190 (P.R. China)
†
Electronic Supplementary Information (ESI) available: Experimental procedure,
and additional Figures. See DOI: 10.1039/x0xx00000x
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
Green Chemistry
Page 2 of 6
COMMUNICATION
Journal Name
2
-n, in which the
shows the TEM images of the prepared Ru/TiO
View Article Online
DOI: 10.1039/C8GC03529F
product consists of uniform Ru nanoparticles (NP) with
spherical shape and an average diameter of 1.8 ± 1.0 nm. The
loading content of Ru was analyzed by inductively coupled
plasma (ICP) mass spectrometry (Table S1 of the Supporting
Information). The HRTEM images (Fig. 2D) clearly reveals that
the lattice spacing of the Ru nanoparticles is ca. 0.20 nm,
which is consistent with the lattice spacing of (101) plane of
metallic Ru. The High-angle annular dark field scanning
transmission electron microscopy (HAADF-STEM) images
analysis reveals that the Ru nanoparticles are evenly dispersed
Fig. 1 SEM images with different magnifications of (A, B) on TiO
TiO -o, (C, D) TiO -d, (E, F) TiO -n.
mapping of the Ru/TiO
suggesting that all elements are evenly distributed.
The typical scanning electron microscope (SEM) images of Furthermore, Fig. S2 shows the energy dispersive X-ray (EDX)
TiO -x (TiO -o, TiO -d and TiO
-n) are shown in Fig. 1. As shown result of Ru/TiO -n samples. It can be seen that except for the
in the Fig. 1A and Fig. 1B, the typical octahedron of TiO
has elements of Ti and O from the catalyst, the Ru elements were
been successfully prepared and the average side length of ca. observed, indicating that Ru nanoparticles were successfully
00 nm and thickness of about 500 nm. The TiO
-o has very deposited on the TiO nanosheet. For comparison, the
few (001) faces leak out. The proportion of (001) facets as well Ru/TiO -o and Ru/TiO -d catalysts also prepared by the same
as morphology of TiO
nanoproducts could be tailored by reduction process and the TEM images have also been shown
simply adjusting the preparation methods. The decanedron in Fig. S3. The nanoparticles with an average diameter of 1.3
bipyramid TiO
structures (Fig. 1C and Fig. 1D) with an average nm (inset of Fig. S3A) are immobilized uniformly on the TiO -o.
side length of ca. 120 nm have been synthesized, which The Ru/TiO -d include uniform spherical nanoparticles with an
average diameter of 1.8 nm (inset of Fig. S3B). The TEM images
nanosheets (Fig. 1E, of the commercial TiO (Ru/TiO -com.) were also shown in Fig.
2
(Fig. 2E). In energy-dispersive X-ray spectroscopy (EDS)
2
-n catalyst, Ti, O, and Ru were detected,
2
2
2
2
2
2
2
2
2
3
2
2
2
2
2
2
2
2
3
5
correspond to 14.9% facets exposed on the surface of TiO
2
.
To get more of the (001) facets, the TiO
2
2
2
Fig. 1F) with an average side length of ca. 40-70 nm and S4. The Ru nanoparticles in these supported catalysts have
thickness of about 5 nm have been obtained. The geometric similar particle sizes.
3
6
calculation shows an exposure percentage of about 91%.
2 2 2
Fig. 3 (A)XRD patterns of pristine (A)TiO -n, TiO -d, TiO -o and
(
B) Ru/TiO -n, Ru/TiO -d, Ru/TiO -o.
2
2
2
Fig. 2 (A) TEM images of TiO
of TiO nanosheets. (C) TEM images of Ru/TiO
HRTEM images of Ru nanoparticles. (E) HAADF-STEM images presented in Fig. 3. The diffraction peaks could be indexed to
and EDS elemental mapping images (Ti, O, and Ru elements) of anatase-phase TiO (JCPDS No. 78-2486), indicating that the as
the Ru/TiO nanosheets.
synthesized product was pure anatase TiO . It is noteworthy
that with increasing (001) crystal face amount of TiO -o and
The typical transmission electron microscopy (TEM) images TiO -d, the XRD peak intensities of the samples steadily
of Ru/TiO
are shown in Fig. 2. The Fig. S1 is potassium titanate increase and the (001) peaks of the TiO nanosheets become
TEM image showing that the product contains a large quantity enhanced. These phenomena indicate that more and more
of nanowires with narrow size distribution. The diameters of (001) of TiO is exposed. It was noteworthy that no obvious
the nanowires are uniform and around 10 nm and the lengths diffraction peaks of metallic Ru were observed in the Ru/TiO
range from 500 nm up to 1 mm. Fig. 2A indicates that TiO
support was synthesized with an average side length of ca. 40- long-range ordering to facilitate visible XRD peaks.
0 nm. Fig. 2B shows the High-Resolution transmission
2
nanosheets. (B) HRTEM image
To further confirm the compositions of the catalyst, the X-
nanosheets. (d) ray diffraction (XRD) pattern has been performed and
2
2
2
2
2
2
2
2
2
2
2
-n catalyst, which mainly because very small particles do not have
2
7
electron microscopy (HRTEM) which the lattice spacing parallel
to the top and bottom facets is 0.235 nm, corresponding to the
2
(001) planes of anatase TiO crystals. Furthermore, Fig. 2C
2
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
Page 3 of 6
Green Chemistry
Journal Name
COMMUNICATION
Table 1. Catalytic Performance of Different Catalysts in the
Hydrogenation of LAa
View Article Online
DOI: 10.1039/C8GC03529F
O
O
O
O
AI
O
OH
O
LA
O
GVL
OH
OH
HPA
Time
Conversionb
/ %
Selectivity / %
c
TOF
/ h
d
Entry
Catalysts
-
1
/
h
HPA
AI
GVL
1
2
3
4
5
6
no
4
-
>99
63
54
25
21
-
63
28
-
-
-
-
-
-
-
Ru/TiO
Ru/TiO
Ru/TiO
Ru/TiO
Ru/C
Ru/TiO
Ru/TiO
Ru/TiO
Ru/TiO
2
2
2
-n
-d
-o
8
8
8
4
4
4
8
8
8
>99 41.5
18.2 1.5 80.3 23.4
25.2 2.0 72.8 12.8
43.5
9.7
-
67.2
-
-
Fig. 4 Ru 3d5/2 XPS spectra of TiO
2 2
-supported Ru (Ru/TiO -n,
Ru/TiO -d and Ru/TiO -o).
2
2
e
2
-c
-
-
-
-
-
-
56.5 9.2
90.3
-
32.8
>99
-
-
-
-
-
-
f
In order to further study the interaction between metal
and support. The XPS showed that the enhanced activity and
7
8
9
1
2
-n
-n
-n
-n
g
2
2
2
h
stability of Ru/TiO
interaction between Ru nanoparticles and TiO
-n catalysts may be attributed to the
nanosheet.
2
0i
2
Notwithstanding, the Ru 3d3/2 signal interferes with the C 1s
signal and thus is difficult to resolve. Ru 3d5/2 was not affected
by C 1s, so we measured Ru3d5/2 to study the oxidation states
of Ru. As shown in Fig. 4, the oxidation state of Ru metal was
a
Reaction conditions: LA (1.0 mmol), H
2
O (2 mL), catalyst (20
o
mg), T (30 C), PH2(3 MPa), stirring speed (800 rpm).
b
c
Conversion of LA was determined by GC. Selectivity of GVL
d
-1
was determined by GC. TOF = mol of product/ mol of (Ru)×h
different in Ru/TiO
Ru 3d5/2 binding energy of Ru/TiO
deconvolution indicates that the surface composition is 87.1%
2
-n, Ru/TiO
2
-d and Ru/TiO
2
-o catalyst. The
e
(
2
conversion of LA is less than 10%) TiO -c is commercial
2
-o is 281.27 eV. The peak
f
g
h
i
2 2
anatase TiO . Without H . methanol. alcohol. 1,4-dioxane.
The hydrogenation and dehydration of LA was carried out Ru (IV) and 12.9% Ru (0). The Ru 3d5/2 binding energy of
in aqueous solutions (Table 1). In 4 hours, the conversion of LA Ru/TiO -d is 280.99 eV and the peak deconvolution indicates
was 65%, 41%, 32% for the Ru/TiO -n, Ru/TiO -d and Ru/TiO
-o, that the surface composition is 85.8% Ru (IV) and 14.2% Ru (0).
respectively (Fig. S5). More importantly, the selectivity of GVL These results show that Ru nanoparticles are easily oxidized.
was about 90% over Ru/TiO
-n. However, the selectivity of GVL The other hand, the degree of oxidation is different on the
is only 76.5%, 60.0% for Ru/TiO -d and Ru/TiO
-o, the different crystal surfaces. More interesting, the Ru 3d5/2
byproduct is AI and HPA. When the reaction time was binding energy of Ru/TiO -n is 280.39 eV and the peak
extended to 8 hours, the yield of GVL could be 99% over deconvolution indicates that the surface is composed of 61.8%
Ru/TiO
-n, LA could completely transform into the desired Ru (IV) and 38.2% Ru (0). These results indicate that the
products. However, In the same reaction conditions, Ru/TiO
-d surface of Ru/TiO -n contains more Ru (0). It may be that the
and Ru/TiO
-o need more reaction time for the hydrogenation surface of TiO -n has more defect sites, which leads to
2
2
2
2
2
2
2
2
2
2
2
2
2
and dehydration of LA reaction, the conversion of LA and the stronger metal interaction with the support. Because TEM
selectivity of GVL were 63%/80.3% and 54%/72.8%, already showed that the nanoparticles size of Ru are similar for
respectively (entry 3 and entry 4, Table 1). As a comparison, Ru/TiO
the conversion of GVL was only 25% over Ru/TiO
-com. under higher activity is attributed to the presence of more surface Ru
the same conditions for the hydrogenation and dehydration of (0) for Ru/TiO -n.
LA (entry 5, Table 1). Surprisingly, the Ru/TiO -n catalysts
2 2 2
-o, Ru/TiO -d and Ru/TiO -n catalyst. It means that
2
2
2
prepared in this work could catalyze the reaction very
efficiently with the higher TOF (entry 2, Table 1). The
commercial-Ru/C(Ru/C-com.) also showed poor catalytic
activity (entry 6, Table 1). The reaction results of these
catalysts proved that TiO -n as support had high catalytic
2
activity for hydrogenation of LA. When the hydrogen
atmosphere absent, the GVL was not produced (entry 7, Table
1
). This shows that hydrogen was indispensable. Furthermore,
the influence of different solvent on the hydrogenation of LA
was studied and the results were shown in Table 1(entry 8-10).
It can be seen that methanol and alcohol exhibited very low
conversion of LA(63%, 28%), respectively. There is almost no
2
Fig. 5 (A) Reusability of Ru/TiO -n under the condition given
as entries 1-4 in Table 1. (B) TEM images of the catalyst after
cycling.
reaction in 1,4-dioxane solvent. H
among the solvents we checked. The yield of GVL could reach
9% in H O.
2
O was the best solvent
2
To verify the durability of the Ru/TiO -n catalyst, the
reusability was tested for the hydrogenation and dehydration
of LA to GVL. After the reaction, the reaction mixture was
9
2
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
Green Chemistry
Page 4 of 6
COMMUNICATION
Journal Name
centrifuged and the solid Ru/TiO
2
-n catalyst was recovered, 10.
J. Q. Bond, D. M. Alonso, D. Wang, R. M. WVieewstAraticnledOJn.liAne.
Dumesic, Science, 2010, 327, 1110D-1O1I1: 140..1039/C8GC03529F
C.-H. Zhou, X. Xia, C.-X. Lin, D.-S. Tong and J. Beltramini,
Chemical Society Reviews, 2011, 40, 5588-5617.
J. Q. Bond, A. A. Upadhye, H. Olcay, G. A. Tompsett, J. Jae,
R. Xing, D. M. Alonso, D. Wang, T. Zhang, R. Kumar, A.
Foster, S. M. Sen, C. T. Maravelias, R. Malina, S. R. H.
Barrett, R. Lobo, C. E. Wyman, J. A. Dumesic and G. W.
Huber, Energy & Environmental Science, 2014, 7, 1500-
followed by rinsing with THF and centrifugation (3×30 mL). The
1
1
1.
2.
Ru/TiO
2
-n catalyst was reused directly for the next run after
o
drying at 60 C for 12 h in a vacuum oven. The results in Fig. 5A
clearly showed that the catalysts can be used at least 5 times
without obvious decrease in the conversion of LA and the
reaction selectivity. The TEM image of the Ru/TiO
2
-n after used
5
times is shown in Fig. 5B. It can be seen that the Ru
nanoparticles didn’t aggregate compared with the virgin
catalyst.
1
523.
13.
B. Girisuta, L. Janssen and H. J. Heeres, Industrial &
Engineering Chemistry Research, 2007, 46, 1696-1708.
J. J. Bozell and G. R. Petersen, Green Chemistry, 2010, 12,
In summary, we have demonstrated a facile and efficient
strategy for facilitating the GVL from LA by using quantum- 14.
sized Ru dots decorated ultra-thin anatase TiO nanosheets as
the catalysts under mild conditions. The support effect has
been largely attributed to the high energy of TiO (001) which
5
39-554.
W. R. H. Wright and R. Palkovits, ChemSusChem, 2012, 5,
657-1667.
W. Li, J.-H. Xie, H. Lin and Q.-L. Zhou, Green Chemistry,
012, 14, 2388-2390.
2
1
1
1
1
1
5.
6.
7.
8.
9.
1
2
leads to the stronger interaction of the Ru nanoparticles and
the support. More Ru (0) is important for the improving
activity of the Ru/TiO -n. The results could also provide helpful
2
insights for the efficient catalyst for the other reaction using
high energy support.
2
J. Q. Bond, D. M. Alonso, R. M. West and J. A. Dumesic,
Langmuir, 2010, 26, 16291-16298.
S. G. Wettstein, D. M. Alonso, Y. Chong and J. A. Dumesic,
Energy & Environmental Science, 2012, 5, 8199-8203.
F. D. Pileidis and M.-M. Titirici, ChemSusChem, 2016, 9,
5
62-582.
Conflicts of interest
20.
P. J. Deuss, K. Barta and J. G. de Vries, Catalysis Science &
Technology, 2014, 4, 1174-1196.
The authors declare no conflicts of interest.
2
2
1.
2.
A. M. R. Galletti, C. Antonetti, V. De Luise and M.
Martinelli, Green Chemistry, 2012, 14, 688-694.
P. P. Upare, J.-M. Lee, D. W. Hwang, S. B. Halligudi, Y. K.
Hwang and J.-S. Chang, Journal of Industrial and
Engineering Chemistry, 2011, 17, 287-292.
C. Michel, J. Zaffran, A. M. Ruppert, J. Matras-Michalska,
M. Jedrzejczyk, J. Grams and P. Sautet, Chemical
Communications, 2014, 50, 12450-12453.
Acknowledgements
This work was supported by the National Key Research and
2
3.
Development
017YFA0403103), National Natural Science Foundation of China
21603235), Chinese Academy of Sciences (QYZDY-SSW-SLH013),
Program
of
China
(2018YFB0605801,
2
(
2
2
2
2
2
4.
5.
6.
7.
8.
Z.-p. Yan, L. Lin and S. Liu, Energy & Fuels, 2009, 23, 3853-
the Recruitment Program of Global Youth Experts of China.
3
858.
B. Coq, A. Bittar and F. Figueras, Applied Catalysis, 1990,
9, 103-121.
5
Notes and references
M. G. Al-Shaal, W. R. H. Wright and R. Palkovits, Green
Chemistry, 2012, 14, 1260-1263.
C. Xiao, T.-W. Goh, Z. Qi, S. Goes, K. Brashler, C. Perez and
W. Huang, Acs Catalysis, 2016, 6, 593-599.
S. Ishikawa, D. R. Jones, S. Iqbal, C. Reece, D. J. Morgan, D.
J. Willock, P. J. Miedziak, J. K. Bartley, J. K. Edwards, T.
Murayama, W. Ueda and G. J. Hutchings, Green
Chemistry, 2017, 19, 225-236.
1
.
N. Ta, J. J. Liu, S. Chenna, P. A. Crozier, Y. Li, A. Chen and
W. Shen, Journal of the American Chemical Society, 2012,
1
34, 20585-20588.
2
.
D. Zhao, Q. Huo, J. Feng, B. F. Chmelka and G. D. Stucky,
Journal of the American Chemical Society, 2014, 136,
1
0546-10546.
3
4
5
6
.
.
.
.
W. Jiang, B. Xu, Z. Xiang, X. Liu and F. Liu, Applied Catalysis
A: General, 2016, 520, 65-72.
S. Wu, Q. He, C. Zhou, X. Qi, X. Huang, Z. Yin, Y. Yang and
H. Zhang, Nanoscale, 2012, 4, 2478-2483.
J. Lee, J. C. Park and H. Song, Advanced Materials, 2008,
2
G. Chen, R. Gao, Y. Zhao, Z. Li, G. I. N. Waterhouse, R. Shi,
J. Zhao, M. Zhang, L. Shang, G. Sheng, X. Zhang, X. Wen, L.
Z. Wu, C. H. Tung and T. Zhang, Adv Mater, 2018, 30.
A. M. Ruppert, J. Grams, M. Jedrzejczyk, J. Matras-
Michalska, N. Keller, K. Ostojska and P. Sautet,
ChemSusChem, 2015, 8, 1538-1547.
2
3
9.
0.
W. Luo, M. Sankar, A. M. Beale, Q. He, C. J. Kiely, P. C. A.
Bruijnincx
and
B.
M.
Weckhuysen,
Nature
Communications, 2015, 6.
W. Luo, U. Deka, A. M. Beale, E. R. H. van Eck, P. C. A.
Bruijnincx and B. M. Weckhuysen, Journal of Catalysis,
0, 1523-1528.
2
013, 301, 175-186.
X. Q. Gong and A. Selloni, Journal of Physical Chemistry B,
005, 109, 19560-19562.
3
3
1.
2.
2
7
.
F. De Angelis, G. Vitillaro, L. Kavan, M. K. Nazeeruddin and
M. Graetzel, Journal of Physical Chemistry C, 2012, 116,
1
8124-18131.
8
9
.
.
C. Liu, X. Han, S. Xie, Q. Kuang, X. Wang, M. Jin, Z. Xie and
L. Zheng, Chemistry, an Asian journal, 2013, 8, 282-289.
F. Wang, H. Z. Wu, C. L. Liu, R. Z. Yang and W. S. Dong,
Carbohydrate research, 2013, 368, 78-83.
3
3
3.
4.
A. Selloni, Nature Materials, 2008, 7, 613-615.
S. Li, H. Hu and Y. Bi, Journal of Materials Chemistry A,
2
016, 4, 796-800.
3
5.
C. Liu, X. Han, S. Xie, Q. Kuang, X. Wang, M. Jin, Z. Xie and
L. Zheng, Chemistry-an Asian Journal, 2013, 8, 282-289.
4
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
Page 5 of 6
Green Chemistry
Journal Name
COMMUNICATION
3
6.
L. Q. Ye, J. Mao, J. Y. Liu, Z. Jiang, T. Y. Peng and L. Zan,
Journal of Materials Chemistry A, 2013, 1, 10532-10537.
View Article Online
DOI: 10.1039/C8GC03529F
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Please do not adjust margins
Green Chemistry
Page 6 of 6
COMMUNICATION
Journal Name
View Article Online
DOI: 10.1039/C8GC03529F
Shaopeng Li, Yanyan Wang, Youdi Yang,ab Bingfeng Chen, Jing
ab
ab
a
Tai, Huizhen Liu* and Buxing Han*ab
c
ab
Conversion of levulinic acid to γ valerolactone over
ultra-thin TiO nanosheets decorated with ultrasmall Ru
2
nanoparticle catalysts under mild condition
6
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins