The facet-regulated oxidative dehydrogenation of lactic acid to pyruvic acid on α-Fe2O3

Article abstract of DOI:10.1039/d0gc03468a

We propose a highly active α-Fe2O3 catalyst for the oxidative dehydrogenation of lactic acid to value-added pyruvic acid in air. The activity is determined by the utilized crystal face, due to the different adsorption energies of lactic acid molecules on different exposed planes. Furthermore, Fe sites show more preferential adsorption than crystal O sites.

Full text of DOI:10.1039/d0gc03468a

View Article Online
View Journal
Green
Chemistry
Cutting-edge research for a greener sustainable future
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: C. Yin, X. Li, Y. Dai,
Z. Chen, Y. Dingfeng, R. Liu, W. Zou, C. Tang and L. Dong, Green Chem., 2021, DOI:
10.1039/D0GC03468A.
Volume 20
This is an Accepted Manuscript, which has been through the
Number
May 2018
Pages 1919-2160
9
7
Royal Society of Chemistry peer review process and has been
accepted for publication.
Green
Chemistry
Cutting-edge research for a greener sustainable future
rsc.li/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
Information for Authors.
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 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
PAPER
Paul T. Anastas et al.
The Green ChemisTREE: 20 years after taking root with the 12
principles
rsc.li/greenchem

Please do not adjust margins
Page 1 of 6
Green Chemistry
View Article Online
DOI: 10.1039/D0GC03468A
Facet-Regulated Oxidative Dehydrogenation of Lactic Acid to
Pyruvic Acid on α-Fe2O3
Chunyu Yin,a Xinli Li,*a Yunsheng Dai,b Zhi Chen,a Dingfeng Yang,a Ruixue Liu,a Weixin Zou,c
Received 00th January 20xx,
Accepted 00th January 20xx
Congming Tang *a and Lin Dong c
DOI: 10.1039/x0xx00000
We propose
a
highly active α-Fe2O3 catalyst for oxidative conversion and 75.3% of PA selectivity14. These investigations
dehydrogenation of lactic acid to value-added pyruvic acid with air. mainly focused on the relation between activity and chemical
The activity is determined by crystal face due to different composition, and the correlation between the crystal plane
adsorption energies of lactic acid molecule on the exposed plane. structure of catalyst and the activity was peculiarly lacking.
Furthermore, Fe site is more preferentially adsorbed than crystal O Thus, it requires continuous effort to reveal the structure-
site.
activity relationship for deep understanding the mechanism on
oxidative dehydrogenation of LA to PA.
Biomass and its derivatives, as renewable resources are desired
to produce chemicals and fuels, instead of fossil resources such
as petroleum, coal and natural gas1, 2. Like ethene and
In recent years, the constructed nano-catalysts with
specific morphology, particle size and crystal structure have
displayed a promising application in whether thermal catalysis15
or cool catalysis including photocatalysis16-18 and electro-
catalysis19. Consequently, the basic principles related to
acetylene, lactic acid (LA) is acted as a platform molecule for
4
producing various chemicals such as pyruvic acid (PA)3,
,
8
propionic acid5, acetaldehyde6, acrylic acid7,
,
2,3-
structural-selectivity correlations can be directly addressed. α-
pentanedione9 and polylactic acid10. Pyruvic acid (PA), a vital
intermediate, is widely used in chemical, pharmaceutical, food,
agriculture, environmental protection and other fields3.
Compared with traditionally industrial production of PA from
tartaric acid, consuming stoichiometric amount of potassium
hydrogen sulfate and high energy, direct catalytic synthesis of
PA from LA via oxidative dehydrogenation is viewed as a
16, 17
Fe2O3
is naturally abundant and environmentally benign,
and displays a bright prospect in chemical industry. Herein, by
catalyst characterization and first-principle calculation based on
Density Functional Theory, we discuss the selective oxidative
dehydrogenation of LA on four regularly shaped α-Fe2O3
crystallites (nano-truncated hexagonal bipyramid (THB), nano-
cubes (QC), nano-plates (HS) and nano-spheres (RC)) with well-
defined facets and disclose the structure-activity relationship.
The research findings will provide a very powerful method for
catalytic synthesis of oxy-organics from biomass and its
derivatives.
In order to understand the true performance of the as-
prepared catalyst, preliminary experiments were carried out on
the internal and external diffusion limits20, 21, and the results
were shown in Fig. S1 and Fig. S2. Catalyst particle size of 20-40
meshes along with the LA flow rate of 2 mL h-1 was selected to
evaluate the catalytic performance of samples during the
catalytic oxidative dehydrogenation of LA to PA, which fully
eliminated the influence of mass transfer. Initially, over the α-
Fe2O3 with different morphologies catalytic activity for oxidative
dehydrogenation of LA to PA was investigated and the results
were shown in Table 1 and Fig. S3a-b. Conversion of LA
drastically changed with the morphology of α-Fe2O3. LA was
almost completely converted with RC and HS. However, the
conversion of LA was less than 50% for THB and QC. Similar to
the tendency of LA conversion with the morphology of α-Fe2O3,
PA selectivity decreased from 81.7% with RC to only 2.1% over
THB. The formation of other products such as acetaldehyde,
acetic acid, and acrylic acid was also influenced by α-Fe2O3 with
different morphologies (Table S1). In terms of LA conversion
and PA selectivity, RC offered more excellent performances
than other catalysts.
potential and environmental route3, 11
.
On oxidative dehydrogenation of LA to PA, iron phosphates
were firstly used, and the M phase composing of Fe2+ and Fe3+
showed the catalytic performance with LA conversion of 60%
and PA selectivity of 62%12, 13. Later, metal and its oxides were
investigated by several groups. Notably, Pb-Pt bimetallic
supported on carbon materials displayed better activity,
achieving 70.7% of LA conversion together with 80.1% of PA
selectivity3. Besides, bimetallic oxides such as Nb-Ni-O11, and
Mo-Ti-O4, have also been investigated for this reaction,
obtaining 30.5% of LA conversion and 50.3% of PA selectivity for
the former, and 60.6% of LA conversion and 80.2% of PA
selectivity for the latter. Recently, the activity on oxidative
dehydrogenation of LA to PA has been further enhanced by P
modified Fe-Mo bimetallic oxides, achieving 88.7% of LA
a. C.Y. Yin, Dr. X.L. Li, Dr. Z. Chen, Dr. D.F. Yang, R.X. Liu, Prof. Dr. C.M. Tang
School of Chemistry and Chemical Engineering
Chongqing University of Technology
Chongqing 400054, PR China
E-mail: lixinli@cqut.edu.cn (X.L. Li), tcmtang2001@cqut.edu.cn(C.M. Tang)
b. Prof. Dr. Y.S. Dai
Catalysis
Sino-Platinum Metals Co., Ltd.
Kunming 650106, PR China
c. Dr. W.X. Zou, Prof. Dr. L. Dong
Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis
Nanjing University
Nanjing 210093, PR China
Electronic Supplementary Information (ESI) available: [details of any supplementary
information available should be included here]. See DOI: 10.1039/x0xx00000x
To evaluate the reactivity of hematite architectures
quantitatively, the apparent reaction rate constant (k)22 of LA
Please do not adjust margins

Please do not adjust margins
Green Chemistry
Page 2 of 6
Journal Name
COMMUNICATION
View Article Online
DOI: 10.1039/D0GC03468A
Table 1. Comparison of reactivity in the conversion of Lactic acid to pyruvic acid over α-Fe2O3 with different morphology, along with other catalysts from the
literatures.
Catalytic performance
Entry
Catalyst
Ref.
LA Conv.
[%]
k
ks
stability
[h]
SSA
[m2 g-1] [c]
Dominant
planes[d]
PA Sel. [%]
[h-1] [a]
[h-1 m-2] [b]
1
2
3Pb-1Pt/CB
Fe(PO4)3
Mo/Fe(PO4)3
Nb-Ni-O
Mo-Ti-O
FeMoO/P
THB
70.7
60.2
70.1
30.5
60.6
88.7
36.7
43.1
94.0
94.6
80.6
62.3
63.2
50.3
80.2
75.3
2.1
N/A
N/A
N/A
N/A
N/A
N/A
1.27
1.28
7.49
13.13
N/A
N/A
N/A
N/A
N/A
N/A
0.23
0.49
0.95
2.02
N/A
N/A
N/A
10
756
N/A
N/A
48
N/A
N/A
3
12, 13
23, 24
11
3
N/A
4
N/A
5
N/A
60
N/A
23.7
12.82
7.97
21.26
16.91
N/A
4
6
N/A
14
7
N/A
N/A
N/A
100
{113}
{012}
{001}
{001}
This work
This work
This work
This work
8
QC
4.2
9
HS
55.3
81.7
10
RC
[a] The apparent reaction rate constant (k) of oxidative dehydrogenation of LA to PA on α-Fe2O3 architectures is calculated based on a pseudo-first-order
kinetic model. [b] ks represents the rate constant (k) normalized to SSA. ks=k (catalyst mass SSA)-1. [c] The specific surface area, (SSA). [d] Dominant
planes are confirmed using TEM and HRTEM. This work conditions: catalyst, 0.30-0.40g; reaction temperature 230 oC; particle size, 20-40 meshes; carrier
gas air, 3 mL min−1; LA feedstock, 10 wt% in water, feed flow rate, 2 mL h−1, TOS on 4-5 h.
to PA was calculated, and the results were also summarized in
Table 1 and Figure 1a. For the blank experiment without
catalyst, the oxidative dehydrogenation of LA to PA was
relatively slow at 230 oC, with an apparent reaction rate
constant k=0.45 h-1. Under the identical experimental
conditions, the apparent reaction rate in the presence of
catalysts was conspicuously elevated, and k was normalized to
the specific surface area in order to explore intrinsic catalytic
activity, referred to ks25, 26. RC shows the greatest catalytic
activity with ks=2.02 h-1 m-2, while ks are 0.23, 0.49 and 0.95
h-1 m-2 for THB, QC and HS, respectively. From the standpoint
of industrial application, the stability test is extremely
significant for the study of heterogeneous catalysts27. The
stability test of RC was carried out under controlling the initial
LA conversion at less than 60% by reducing the amount of
catalyst in order to realize adequately saturation of active
sites of the catalyst by reaction molecules, and ensure
authentic stability (Figure 1b). We can clearly observe that LA
conversion always remains at 50% and PA selectivity almost
maintains constant (~81%)
selectivity of PA still maintained around 80% during 100 h on
stream. For the reported FeMoO/P14, the LA conversion was
reduced by around 10% within 60 h, and no longer reaction
time was studied. In comparison, the stability of the α-Fe2O3-
RC catalyst displayed more excellent stability.
Why is obviously different for the activity of α-Fe2O3 with
different morphologies? We expected that α-Fe2O3 with
different morphologies expose different crystal facets, and the
Fe/O atomic ratio in their corresponding crystal facet is also
different, resulting in different oxidation property and
reactivity. In order to further verify the assumption, the
structure, morphology and oxidation state of the as-prepared
α-Fe2O3 architectures were characterized. Different samples
remain unanimous characteristic diffraction peaks (Fig. 2a),
suggesting a pure phase in α-Fe2O3 form (JCPDS NO. 33-0664).
Furthermore, the SEM images (Fig. 2b-e) show that four
samples present obviously different morphologies, namely,
nano-truncated hexagonal bipyramid (THB), nano-cubes (QC),
nano-plates (HS) and nano-spheres (RC).
Fig. 1. Excellent activity and stability of a-Fe2O3-RC. a), A kinetic study of LA to
PA showing activity order of RC＞HS＞QC＞THB＞Blank. The errors of each
conversion (after t hour) were evaluated to be within 2%. b), Stability test of
a-Fe2O3-RC for LA to PA, reaction conditions: reaction temperature 230 °C;
catalyst, 0.1 g; particle size, 20-40 meshes; carrier gas air, 3 mL min−1; LA
Fig. 2. XRD patterns of the α-Fe2O3 (a), SEM images of (b) α-Fe2O3-THB, (c) α-Fe2O3-
QC, (d) α-Fe2O3-HS and (e) α-Fe2O3-RC.
A TEM image for THB is shown in Fig. S4a and the
illustration of a structural model in Fig. S4b28. All of the THB
display a well-defined pseudo-hexagon shape. Based on a SEM
(Fig. 2b) and TEM analysis, the crystallites are composed of
two truncated facets and twelve side planes. A classic HRTEM
feedstock, 10 wt% in water, feed flow rate, 2 mL h−1
.
during 100 h on stream. It is generally difficult to obtain high
conversion and high selectivity simultaneously. Thus the
stability at high conversion of LA was also investigated (Figure
S3c). Encouragingly, at high LA conversion of 95%, the
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 6
Journal Name
Green Chemistry
Please do not adjust margins
COMMUNICATION
View Article Online
DOI: 10.1039/D0GC03468A
image (Fig. S4b) and fast Fourier transform (FFT; inset in exposes the {104}, {012}, and {110} family planes, and each
Figure. S4b) show that four side facets were determined to be occupies 1/3 of the whole surface28. HS exposes the {001} and
(-1-2-4), (124), (-1-24) and(12-4), belonging to the {214}; while {110} family planes, and each takes up 7/9 and 2/9 of the
the other eight side facets were confirmed to be (2−13), whole surface, respectively28. RC exposes the {001} facets,
(−123), (−21−3), (−12−3), (1−2−3), (2−1−3), (−213), and (1−23) exclusively. Thus, the dominant exposed planes on the four α-
belonging to the {113}; and the two truncated facets belong to Fe2O3 catalysts, THB, QC, HS and RC, are {113}, {012}, {001} and
{104}. A SEM (Fig. 2c) and TEM image (Fig. S4c) indicate that {001}, respectively. While the order of catalytic activity of four
nano-cubes (QC) seem to be quasi cubic in shape and the α-Fe2O3 catalysts is THB < QC < HS < RC. It is clearly concluded
diagram of a structural model in Fig. S4d. A HRTEM image (Fig. that the facet {001} is active for oxidative dehydrogenation of
S4d) and fast Fourier transform (FFT; inset in Figure. S4d) show LA to PA.
that QC consists of three pairs of parallel planes, and the
It is necessary for us to further disclose the relation
lattice fringe are 0.25 nm and 0.22 nm. Dihedral angle between activity and facets in order to understand why the
between adjacent planes are 84°, 90° and 96°. The above data facet {001} is active for production of PA from LA. The
show that the QC exposed {012}, {104} and {110}29. A SEM (Fig. adsorption energies of LA molecule on various surfaces of α-
2d) and TEM image (Fig. S4e) reveal that nano-plates (HS) Fe2O3 were evaluated by DFT calculations, and the results
seem to be a hexagonal shape and the illustration of a were shown in Table S2 and Fig. S6a. Clearly, the surface
structural model in Fig. S4f. In view of SEM and TEM analysis adsorption energy of LA on facet {001} is -0.39 eV, far lower
±
with HS, the thickness and width are confirmed to be (460
than other facets {113} and {012}, which intensifies the
±
20.3) and (14.2
2.1) nm, respectively. A representative adsorption. Lactic acid is adsorbed over α-Fe2O3, and the lower
HRTEM image (Fig. S4f) and fast Fourier transform (FFT; inset the energy required, the easier it is to adsorb on the surface
in Fig. S4f) show that HS is consistent with (110), (−120) and of the catalyst. Further calculation about adsorption energy of
(−210) planes, respectively. And the regular two hexagonal LA molecule on different sites of α-Fe2O3 {001} was
facets are confirmed to {001}. Observed (Fig. S5) vertically performed, and the results were depicted in Table S3-4 and
arranged plates are frequently wedge-shaped and the side Fig. S6b-e. The optimized adsorption structures of LA at
surfaces are determined to {110}30. Shown in Fig. 3a are the different adsorption sites on the α-Fe2O3 (001) facets show
TEM image, HRTEM (FFT; inset in Fig. 3b) and selected area two stable adsorption configurations A (Fe-O) and B (O-H),
electron diffraction (SAED) inset in Fig. 3a. The RC displays a and the adsorption energy of configuration A is lower than B,
well-defined roundness. Based on SEM image (Fig.2e), the suggesting that type A is preferentially adsorbed. It is noted
crystallites comprise of spheroidal particle. Furthermore, the that the ratios of Fe/O on facets are 0.31, 0.46, and 0.60,
TEM image (Fig. 3a) shows the RC crystallites are composed of corresponding to the {113}, {012} and {001}, respectively, and
a
large number of overlapped round particles. The the results are shown in Table 2. This further suggests that the
microcrystals grow along the c-direction ([001] axis)30, which facet {001} is more beneficial for adsorption of LA molecule
can be reflected from the SAED pattern (inset in Fig. 3a). The than other facets. The electronic structures of the four fresh
spherical surface is confirmed to be {001} family planes. A as-prepared samples were explored by diffuse-reflectance UV-
HRTEM image (Fig. 3b) and FFT (inset in Fig. 3b) suggest that Vis spectra and derived Tauc plots. Fig. S7a shows that all α-
three sets of lattice fringes (0.25 nm) match well to (-120),
Fe2O3 sample possess a comparable absorption edges around
550-600 nm.
Table 2. The atomic density of surface O and Fe atoms on the {113}, {012}, {001} planes.
Atomic density [nm-2]
{113}
{012}
{001}
Surface O
Surface Fe
Fe/O ratio
8.4
2.6
10.8
4.7
7.7
4.6
0.31
0.46
0.60
The band gaps (Eg) are confirmed to be 2.13, 2.10, 2.14, 2.15
eV for THB, QC, HS and RC, respectively. Larger band gap
indicates smaller particle size of sample, producing larger
specific area and favoring the transport of hot electron.
According to the empirical formula ECB = X-Ec -1/2Eg (1) and EVB
Fig. 3. a) TEM image of the α-Fe2O3-RC, Insets: SEAD pattern; b) HRTEM image of the
α-Fe2O3-RC, Insets: FFT pattern.
(-210), (110) planes, respectively. Therefore, the base plane of
the α-Fe2O3 nano-sphere is {001}16. The physical parameters = ECB + Eg (2), where ECB is the conduction band (CB) energy,
EVB the valence band energy (VB), X absolute electronegativity
of α-Fe2O3, and Ec a constant relative to the NHE. EVB values
have been obtained as 2.455, 2.440, 2.460 and 2.465 eV for
THB, QC, HS, RC, respectively, by using Ec = 4.50 eV (seen in
Table S5). Larger EVB suggests stronger oxidizability. Binding
energy of RC is the highest among four catalysts from the XPS
of the prepared samples, including specific surface area and
main planes are also summarized in Table 1.
THB exposes the {113}, {214} and {104} family planes, and
each takes up 4/7, 2/7, 1/7 of the whole surface, respectively,
judged from the area fraction of each crystal surface28. QC
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
Journal Name
COMMUNICATION
View Article Online
DOI: 10.1039/D0GC03468A
of Fe 2p shown in Fig. S7b, which has the strongest oxidation
accordingly. At the same time, the type A is preferentially
adsorptive location. As a result, the adsorbed LA molecule can
be effortlessly oxidized by the located Fe (III). In the four
catalysts, RC revealed the lowest reduction peak, centered at
385oC from the result of H2-TPR shown in Fig.S7c,
demonstrating that hydrogen easily reduces surface Fe-O of
catalyst. Similarly, proton transferred from –OH group of LA
easily combined with surface Fe-O of catalyst, leading to form
product of pyruvic acid by removal of H2O, promoting the
oxidative dehydrogenation of LA during the catalytic reaction.
reduction peak temperature, which is not conducive to the
process. If the reaction temperature is increased, it is
beneficial to enhance the oxygen departure on the iron oxide
surface and promote the process. In order to verify the
assumption, we enhanced the reaction temperatures to
observe the activity on THB and QC. As a result, catalytic
performance of THB and QC was improved (Table S6), which
demonstrated that this step has an extent influence in the
oxidative dehydrogenation of lactic acid. The Fe2+ is oxidized
to Fe3+ by O2 in air. Meanwhile the lost lattice oxygen is
replenished. The catalyst returns to the initial state and
completes the catalytic cycle. In the blank experiment, PA was
almost not detected under the condition of lactic acid and air
without catalyst, indicating that molecular oxygen could not
directly oxidize LA to PA. In addition, under the only lactic acid
and catalyst, the PA was observed and the amount of PA
decreased rapidly over time without air, indicating that the
process of oxidative dehydrogenation of PA consumed lattice
oxygen in the catalyst. The departure of lattice oxygen directly
affects the oxidation dehydrogenation of LA, and it is related
to the exposed crystal surface of iron oxide. Therefore, the
crystal surface of iron oxide can effectively regulate the
activity on oxidative dehydrogenation of lactic acid.
Comparing to previous work focusing on amorphous and
non-stoichiometric catalysts in the oxidative dehydrogenation
of LA to PA3, 4, 31, this work reveals that the structure of the
thermo-catalysts on the nanoscale with exclusive
constructions and their corresponding facets are crucial for
the design of high-performance nano-catalysts. The
arrangement and coordination state of the surface atoms have
important influence on the surface properties, including
stability, hydrophilicity, adsorption capacity, etc., and these
properties determine the catalytic activity.
Scheme 1. Reaction mechanism for the oxidative dehydrogenation of LA to PA over the
RC catalyst.
On the basis of the above observations and DFT
calculations on adsorption of lactic acid molecule on the facet
(001), we propose the mechanism on the oxidative
dehydrogenation of LA to PA (Scheme 1). The adsorption
energies of iron and oxygen located at different positions on
the (001) plane for the hydroxyl and carboxyl functional
groups of the lactic acid molecule were calculated (The
detailed adsorption model and results were shown in (Figure
S6a-e and Table S2-4). It is found that the top iron species
(Fe3+) attacks the hydroxyl group of the lactic acid molecule
with the lower adsorption energy, indicating that lactic acid
molecules are adsorbed and activated at the top iron site (1A),
so that O-H bond is broken, and H+ is transferred to the
adjacent oxygen at the iron site to form new Fe-OH. In this
process, the enhancement of iron oxidation state contributes
significantly to activate hydroxyl group. Among four shaped α-
Fe2O3 catalysts, the iron species in RC has a higher electron
binding energy, which means stronger oxidizability. At the
same time, the UV-Vis spectra and valence band analysis show
that RC has a higher valence band, indicating stronger
oxidation, which is consistent with the XPS results. In addition,
the RC mainly exposed with crystal plane (001) has a higher
Fe/O atomic ratio, which also conduces to the Fe site to adsorb
and activate the hydroxyl group in the lactic acid molecule.
Then the formed Fe-OH attacks C-H to break the C-H bond and
form PA. At the same time, the dissociated H+ combines with
Fe-OH to
Conclusions
In summary, the oxidative dehydrogenation of LA to PA with
O2 at 230 oC over hematite is powerfully structural-dependent
and the reactivity trend can be reasonably interpreted as
enclosed facets in the sequence of {001} > {012} > {113}. The
hematite α-Fe2O3 (RC with dominant enclosed {001}) exhibited
remarkable
activity
and
stability
for
oxidative
dehydrogenation of LA to PA. This study demonstrates a
prospective way for thermally catalytic conversion of lactic
acid. In addition, this study has broadened applications of
hematite α-Fe2O3 in biomass and its derivatives.
Conflicts of interest
The authors declare no conflicts of interest.
Acknowledgements
This work was supported by National Natural Science
Foundation of China (22078033), Opening Foundation of
Jiangsu Key Laboratory of Vehicle Emissions Control (OVEC
form water. And the Fe3+ is reduced to Fe2+, supported by H2-
TPR results, since RC has a lower reduction peak, which is
conducive to C-H activation and dissociation. Iron oxides with
other morphologies such as THB and QC have a higher
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 6
Journal Name
Green Chemistry
Please do not adjust margins
COMMUNICATION
View Article Online
DOI: 10.1039/D0GC03468A
049), the fund of the State Key Laboratory of Advanced
Technologies for Comprehensive Utilization of Platinum
Metals (SKL-SPM-202010), Youth/Key Project of Science and
Technology Research Program of Chongqing Education
Commission of China (KJZD-K201901104, KJQN201801109),
Natural Science Foundation of Chongqing (cstc2019jcyj-
msxmX0198) and Special Project of Technology Innovation
and Application Development of Chongqing (cstc2019jscx-
msxmX0002).
Notes and references
1 L. J. Lei, Y. H. Wang, Z. X. Zhang, J. H. An, F. Wang, ACS Catal.
2020, 10, 8788-8814.
2 M. Sayed, N. Warlin, C. Hulteberg, I. Munslow, S. Lundmark,
O. Pajalic, P. Tuna, B. Z. Zhang, S. H. Pyo, R. Hatti-Kaul, Green
Chem. 2020, 22, 5402-5413.
3 C. Zhang, T. Wang, Y. Ding, Appl. Catal. A-Gen. 2017, 533,
59-65.
4 K. Liu, X. Huang, E. A. Pidko, E. J. M. Hensen, Green Chem.
2017, 19, 3014-3022.
5 X. L. Li, J. Pang, J. Zhang, C. Y. Yin, W. X. Zou, C. M. Tang, L.
Dong, Ind. Eng. Chem. Res. 2019, 58, 101-109.
6 C. Tang, Z. Zhai, X. Li, L. Sun, B. Wei, J. Catal. 2015, 329, 206-
217.
7
J. Peng, X. Li, C. Tang, W. Bai, Green Chem. 2014, 16, 108-
111.
8 B. Yan, L.-Z. Tao, Y. Liang, B.-Q. Xu, ACS Catal. 2014, 4, 1931-
1943.
9 X. L. Li, L. W. Sun, W. X. Zou, P. Cao, Z. Chen, C. M. Tang, L.
Dong, ChemCatChem. 2017, 9, 4621-4627.
10 X. H. Zhao, K. Li, Y. Wang, H. Tekinalp, G. Larsen, D.
Rasmussen, R. S. Ginder, L. Wang, D. J. Gardner, M. Tajvidi,
E. Webb, S. Ozcan, ACS Sustain. Chem. Eng. 2020, 8, 13236-
13247.
11 S. Lomate, T. Bonnotte, S. Paul, F. Dumeignil, B. Katryniok,
J. Mol. Catal: A-Chem. 2013, 377, 123-128.
12 M. Ai, K. Ohdan, Appl. Catal. A-Gen. 1997, 165, 461-465.
13 M. Ai, K. Ohdan, Appl. Catal. A-Gen. 1997, 150, 13-20.
14 C. Yin, X. Li, Z. Chen, W. Zou, Y. Peng, S. Wei, C. Tang, L.
Dong, New J. Chem. 2020, 44, 5884-5894.
15 G. Liu, A. W. Robertson, M. M. Li, W. C. H. Kuo, M. T. Darby,
M. H. Muhieddine, Y. C. Lin, K. Suenaga, M. Stamatakis, J.
H. Warner, S. C. E. Tsang, Nat. Chem. 2017, 9, 810-816.
16 X. Zhou, J. Lan, G. Liu, K. Deng, Y. Yang, G. Nie, J. Yu, L. Zhi,
Angew. Chem. Int. Edit. 2012, 51, 178-182.
17 X. Zhou, Q. Xu, W. Lei, T. Zhang, X. Qi, G. Liu, K. Deng, J. Yu,
Small 2014, 10, 674-679.
18 K. Sivula, F. Le Formal, M. Gratzel, ChemSusChem. 2011,
4, 432-449.
19 Y. Z. Zhang, Q. Y. Chen, L. F. Liu, Y. Wang, M. K. H. Leung,
Chem. Eng. J. 2020, 399, 11.
20 S. T. Oyama, X. M. Zhang, J. Q. Lu, Y. F. Gu, T. Fujitani, J.
Catal. 2008, 257, 1-4.
21 A. Sachse, V. Hulea, A. Finiels, B. Coq, F. Fajula, A.
Galarneau, J. Catal. 2012, 287, 62-67.
22 Z. R. Sheng, Y. Watanabe, H. H. Kim, S. L. Yao, T. Nozaki,
Chem. Eng. J. 2020, 399, 14.
23 M. Ai, Appl. Catal. A-Gen. 2002, 234, 235-243.
24 K. Jerabek, L. Hankova, Z. Prokop, E. G. Lundquist, Appl.
Catal. A-Gen. 2002, 232, 181-188.
25 J. J. Erbs, B. Gilbert, R. L. Penn, J. Phys. Chem. C 2008, 112,
12127-12133.
26 A. J. Anschutz, R. L. Penn, Geochem. Trans. 2005, 6, 60-66.
27 P. Liu, E. J. Hensen, J. Am. Chem. Soc. 2013, 135, 14032-
14035.
28 L. Gu, Q. Su, W. Jiang, Y. Yao, Y. Pang, W. Ji, C.-T. Au, Catal.
Sci. Technol. 2018, 8, 5782-5793.
29 G. S. Park, D. Shindo, Y. Waseda, T. Sugimoto, J. Colloid.
Interf. Sci. 1996, 177, 198-207.
30 L. Chen, X. Yang, J. Chen, J. Liu, H. Wu, H. Zhan, C. Liang,
M. Wu, Inorg. Chem. 2010, 49, 8411-8420.
31 C. Gao, J. Qiu, J. Li, C. Ma, H. Tang, P. Xu, Bioresource
Technol. 2009, 100, 1878-1880.
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
View Article Online
DOI: 10.1039/D0GC03468A
Please do not adjust margins