One-Step Encapsulation of Bimetallic Pd–Co Nanoparticles Within UiO-66 for Selective Conversion of Furfural to Cyclopentanone

Article abstract of DOI:10.1007/s10562-020-03133-y

Abstract: The design of efficient catalysts is of important significance for the transformation of biomass into chemicals. In this work, bimetallic Pd–Co nanoparticles were encapsulated within UiO-66 to form a core–shell Pd–Co@UiO-66 catalyst via a facile one-step strategy. The as-synthesized Pd–Co@UiO-66 catalysts were characterized and applied to the selective hydrogenation of furfural (FUR) to cyclopentanone (CPO). Compared with the monometallic Pd@UiO-66, the Pd–Co@UiO-66 could demonstrate excellent performance with 96% CPO selectivity and 99% FUR conversion at 120?°C under 3?MPa H₂ pressure for 12?h. It was found that trace Co had synergetic and promoting effects on the catalytic performance. The core–shell catalysts showed more outstanding recyclability than the supported catalysts, which could maintain high CPO yield after 5th runs. Graphic Abstract: [Figure not available: see fulltext.].

Full text of DOI:10.1007/s10562-020-03133-y

Catalysis Letters
https://doi.org/10.1007/s10562-020-03133-y
One‑Step Encapsulation of Bimetallic Pd–Co Nanoparticles Within
UiO‑66 for Selective Conversion of Furfural to Cyclopentanone
Yanling Wang1 · Cun Liu1 · Xiongfu Zhang1
Received: 2 December 2019 / Accepted: 31 January 2020
© Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract
The design of efcient catalysts is of important signifcance for the transformation of biomass into chemicals. In this work,
bimetallic Pd–Co nanoparticles were encapsulated within UiO-66 to form a core–shell Pd–Co@UiO-66 catalyst via a facile
one-step strategy. The as-synthesized Pd–Co@UiO-66 catalysts were characterized and applied to the selective hydrogena-
tion of furfural (FUR) to cyclopentanone (CPO). Compared with the monometallic Pd@UiO-66, the Pd–Co@UiO-66 could
demonstrate excellent performance with 96% CPO selectivity and 99% FUR conversion at 120 °C under 3 MPa H2 pressure
for 12 h. It was found that trace Co had synergetic and promoting efects on the catalytic performance. The core–shell catalysts
showed more outstanding recyclability than the supported catalysts, which could maintain high CPO yield after 5th runs.
Graphic Abstract
Keywords Selective hydrogenation · Biomass conversion · Heterogeneous catalysis · Hydrothermal synthesis ·
Encapsulation · Nanoparticles
1 Introduction
As the energy crisis and environmental problems become
more prominent, the utilization and subsequent conver-
sion of biomass energy have received more attention to
* Xiongfu Zhang
reduce the dependence on fossil energy efectively [1–3].
xfzhang@dlut.edu.cn
Furfural (FUR), a biomass-based platform compound [4],
1
can be converted into a series of C4 and C5 molecules by a
series of catalytic reactions, e.g. oxidation, hydrogenation,
State Key Laboratory of Fine Chemicals, School
of Chemical Engineering, Dalian University of Technology,
Dalian 116024, China
Vol.:(0123456789)
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Y. Wang et al.
hydrogenolysis, decarboxylation, etc.[5–7]. Among them,
the hydrogenation of FUR can obtain many signifcant prod-
ucts including cyclopentanone (CPO), furfural alcohol (FA),
tetrahydrofurfuryl alcohol (THFA), 2-methylfuran (2-MF),
2-methyltetrahydrofuran (2-MTHF), cyclopentanol (CPL),
etc.[8, 9].
have extensive applications in the catalysis, especially the
catalyst carriers. In order to prevent the aggregation of
metal nanoparticles (MNPs) and improve recyclability,
MOFs materials as the underlying supports were used to
construct supported MNP/MOF or core–shell MNP@MOF
catalysts [29], showing well performance in the hydro-
genation of FUR to CPO. Fang et al. [30] reported the
Ru/MIL-101 which was applied to the hydrogenation of
FUR at 160 °C and 4 MPa H2 for 2.5 h, obtaining the high
CPO selectivity over 96%. In this reaction, MIL-101 could
provide the Lewis acid sites for the required dehydration
step of 4-hydroxy-2-cyclopentenonen (HCP), which was
the key intermediate in the rearrangement of FUR to CPO.
Although the great progress has been made, it is still nec-
essary to develop an efcient and stable catalyst for the
selective conversion of FUR to CPO.
Cyclopentanone (CPO), one of essential downstream
products derived from FUR, has a broad application in
the perfumery, medicine, pesticides and rubber additives
[10, 11]. At present, the industrial preparations of CPO are
mainly through the pyrolysis of adipic acid and oxidation
of cyclopentene which more or less have some drawbacks,
such as complex production processes, energy-extensive
consumption, high input costs and poor economic proft
[12–14]. Therefore, it is urgent to accelerate the develop-
ment of one-pot hydrogenation of FUR to CPO, as a green
environment-friendly preparation method.
UiO-66 [31], which consists of an octahedral central
cage (about 11 Å) and a tetrahedral cage (about 8 Å), con-
tains the regular octahedral [Zr6O4(OH)4] inorganic metal
cluster coordinated with 12 H2BDC organic ligands. The
three-dimensional porous structure and two cage struc-
tures are connected by a triangular window (about 6 Å)
[32]. Due to its structural feature, UiO-66 material exhib-
its excellent thermal and chemical stability, which are the
prerequisites as the suitable catalytic supports [33]. In this
work, UiO-66 was used as the host to encapsulate bime-
tallic Pd-Co to form a core–shell Pd–Co@UiO-66 cata-
lyst via a temperature control program as shown in Fig. 1
[34]. The synthesis route involved the two-step procedure
including frst both the formation of UiO-66 skeleton and
simultaneously the encapsulation of Pd–Co NPs within
UiO-66 at the lower temperature (75 °C), and then subse-
quently the in-situ reduction of Pd–Co NPs at the elevated
temperature (120 °C) by the weak reducibility of the sol-
vent DMF [35]. Compared with monometallic Pd@UiO-
66, the as-synthesized Pd–Co@UiO-66 catalysts with the
loading of trace Co showed excellent catalytic properties
under milder reaction conditions in the selective conver-
sion of FUR to CPO.
Many metals which are used as catalytically active com-
ponents and can be applied in the hydrogenation of FUR,
showing high catalytic activity and selectivity. Generally, the
noble metals (Pd, Pt, Ru, Au, etc.) [15–17] showed excellent
catalytic performance compared with the non-noble ones
(Cu, Co, Ni, etc.) [18–22] on account of high hydrogena-
tion activity and mild reaction conditions. However, the high
costs and low reserves of noble metals limit their widespread
applications [23]. Therefore, it is an admirable strategy for
the introduction of non-noble metals to form bimetallic cat-
alysts which can achieve synergetic efect. For examples,
Hronec et al. [24] prepared the bimetallic 5%Pd-10%Cu/C
catalysts using electroless plating procedure and obtained
98% FUR conversion and 92% CPO yield after 1 h at 160 °C
and 3 MPa H2. The copper existing in Cu+ oxidation state
as Cu2O played essential role in binding and activating the
C=Cbond in FUR.
Moreover, compared with traditional porous materials,
metal–organic frameworks (MOFs) with excellent proper-
ties (such as controllable surface modifcation, abundant
functionality, large specifc surface area, etc.) [25–28]
Fig. 1 The synthetic route of Pd-Co@UiO-66
1 3

One-Step Encapsulation of Bimetallic Pd–Co Nanoparticles Within UiO-66 for Selective Conversion…
2.4 Characterization of Catalysts
2 Experimental
X-ray difractometer (XRD) patterns were obtained on a
D/max-2400X-ray difractometer using Cu-Ka radiation at
40 kV and 100 mA. Scanning electron microscopy (SEM)
images were investigated using QUANTA 450 (FEI Cor-
poration) with an accelerating voltage of 30 kV. The sam-
ples need metal spraying before the tests. The morphol-
ogy and structure of prepared samples were characterized
by transmission electron microscope (TEM) experiments
employing a Tecnai F30 microscope (FEI Company).
Elemental analysis was performed by inductively coupled
plasma-atomic emission spectroscopy (ICP–AES) using
an Optima 2000 DV spectrometer. X-ray photoelectron
spectroscopy (XPS) measurements were performed on an
ESCALAB 250 (Thermo Fisher Company).
2.1 Materials
Zirconium tetrachloride (ZrCl4) was supplied by the
Sigma-Aldrich. Terephthalic acid (H2BDC), acetic acid
(CH3COOH), furfural (FUR), ethanol, methylene chloride
(CH2Cl2), cobaltous nitrate (Co(NO3)2·6H2O), sodium
borohydride (NaBH4) and N, N-dimethylformamide
(DMF) were ofered by the Sinopharm Chemical Reagents
Co. Ltd. (Beijing, China). Palladium (II) acetylacetonate
(Pd(OAc)2) was purchased from the Shanxi Kaida Chemi-
cal Co. Ltd. (Shanxi, China). Cobalt (II) acetylacetonate
(Co(OAc)2) was provided by the Tianjin Guangfu Chemi-
cal Co. Ltd. (Tianjin, China). Palladium Chloride (PdCl2)
was obtained from Shanghai Jiuling Chemical Co. Ltd.
(Shanghai, China). All chemicals above were of analytical
grade and used without further purifcation. The deionized
water (DI water) was home-made.
2.5 Performance of Catalysts
The hydrogenation of FUR was carried out in a 100 mL
stainless steel autoclave equipped with a magnetic stir-
rer and an electric heating jacket. In a typical reaction,
catalysts (30 mg) and FUR (1.8 mmol) were dispersed in
the H2O (20 mL). After replacing the air with H2 for fve
times, the autoclave was heated at 120 °C and pressur-
ized with H2 pressure to 3.0 MPa. After the reaction was
completed, the catalyst was collected by centrifugation
and the supernatant was extracted with dichloromethane
(CH2Cl2). The composition of products was examined
by gas chromatography (GC-7890F, FID, FFAP column
30 m × 0.32 mm × 0.5 μm). The quantitative analysis was
determined by the area normalization. The conversion of
FUR and the selectivity of products in the reaction were
calculated using the following equations:
2.2 Preparation of Core–Shell Catalysts
The synthetic route was as follows: ZrCl4 (0.075 g) and
H2BDC (0.053 g) were added in the DMF (40 mL).
Pd(OAc)2 (0.0065 g) was dissolved in the acetic acid
(3 mL). Above two solutions were mixed. After stirred at
35 °C for 10 h, the solution was reacted at 75 °C for 15 h
and then heated to 120 °C for 4 h. After cooled to room
temperature, the solid was washed with DMF three times
to remove the unreacted precursors and immersed in etha-
nol for 3 days to replace the solvent. In the end, the gray
powders were obtained after drying in vacuum at 60 °C
overnight. The synthesis of Pd–Co@UiO-66 was similar
to that of Pd@UiO-66 except that Co(OAc)2 (0.0013 g)
was added to the synthesis solution.
nFUR − nFUR
Conv. (%) =
× 100%
nFUR
2.3 Preparation of Supported Catalysts
nproduct
Sel. (%) =
× 100%
For comparison, the supported catalysts were also pre-
pared. UiO-66 powders were obtained according to our
previous research [36]. The prepared UiO-66 (0.150 g)
and 2 mg/L H2PdCl4 (12 mL) were mixed and stirred for
3 h. Besides, quantitative Co(NO3)2·6H2O was added in
the mixture to form the bimetallic supported Pd-Co/UiO-
66 catalysts. Finally, 5 mM NaBH4 (10 mL) was used to
reduce MNPs. The solid was washed with water three
times and dried in vacuum at 60 °C for 12 h.
Σnproduct
where nFUR is the number of moles of FUR before the
reaction, nFUR is the number of moles of FUR after the
reaction, nproduct is the number of moles of specifc product,
and Σnproduct is the number of moles of all products.
1 3

Y. Wang et al.
Fig. 2 SEM images of Pd-Co@UiO-66 (a), XRD pattern (b) and XPS spectra (c, d) of diferent catalysts
of electronic structure of Pd atoms, which could be indica-
tive of the formation of Pd-Co alloy [23].
3 Results and Discussion
From the TEM images of Pd-Co@UiO-66 (Pd loading
was 2.4 wt%), Pd–Co alloy was uniformly dispersed within
the UiO-66 framework with an average particle size of ca.
2.1 nm (Fig. 3). Moreover, no conglomerations of Pd–Co
alloy could be detected on the UiO-66 surface, further con-
frming that MNPs were encapsulated into the UiO-66 [39].
But there was no any information about Co detected by ICP
experiments probably because the loading of trace Co in the
catalyst was not within the detection limits.
3.1 Characterization of Catalysts
Figure 2 presents the characterization results of diferent
samples. It was clearly seen that Pd–Co@UiO-66 particles
exhibited a regular octahedron with the size of ca. 600 nm,
which was a typical crystal morphology of UiO-66 mate-
rial despite the diferent metal loadings (Fig. 2a). Accord-
ing to the X-ray difraction (XRD) patterns (Fig. 2b), the
loading of MNPs has no obvious impact on the crystallin-
ity of UiO-66. However, on account of the small particle
sizes of Pd and Co NPs and the low metal loadings, it
is difcult to observe the characteristic peak of both Pd
and Co phase [37]. X-Ray photoelectron spectroscopy
(XPS) was used to determine the electronic environment
of metals (Fig. 2c, d). The Pd 3d3/2 and 3d5/2 peaks were
located around 341.9 eV and 336.6 eV over Pd@UiO-66,
confrming the existence of zero-valent Pd species [38].
Furthermore, the Pd 3d characteristic peaks transferred
to higher binding energy increasing by 0.6 eV over the
bimetallic catalysts. The results refected the modifcation
3.2 Catalytic Performance
As illustrated in Fig. 4, the hydrogenation of FUR has
many reaction pathways. Firstly, both the C=O bond in the
side chain and the C=C bond on the furan ring of FUR, as
unsaturated functional groups, can be theoretically hydro-
genated. However, the C= C bond easily conjugates with
the lone pair electrons of oxygen atom to form the pi bond
and has better stability than the C=O bond [40]. Thus,
the C=O bond is preferentially hydrogenated to form FA.
Next, there are three diferent routes in the conversion of
1 3

One-Step Encapsulation of Bimetallic Pd–Co Nanoparticles Within UiO-66 for Selective Conversion…
Fig. 3 TEM images of Pd-Co@UiO-66 (a–c) and the corresponding size distribution
Fig. 4 Reaction pathways of the hydrogenation of furfural
FA among which the rearrangement of FA to CPO is our
target route. Simultaneously, although a small amount of
2-MF and 2-MTHF are formed by the C-O bond breaking
at high temperature, THFA produced by the hydrogena-
tion of the C=C bond is the major by-product. In addition,
there are some ring-opening products such as 1,5-Pentan-
ediol (1,5-PDO), 1,2-Pentanediol (1,2-PDO), 5-hydroxy-
2-pentanone, etc. CPO is not easily further hydrogenated
to form more stable CPL since the furan polymer covers
on the catalyst surface [41].
Table 1 lists the hydrogenation results of FUR over dif-
ferent catalysts. The conversions of FUR remained at nearly
100% as the Pd contents varied from 1.5 wt% to 3 wt%
over the Pd@UiO-66 (Entries 1–3). When Pd content was
increased to 4% (Entry 4), it was possible that Pd NPs aggre-
gated on the catalyst surface, leading to the decrease in the
1 3

Y. Wang et al.
Table 1 Hydrogenation of FUR
over diferent catalystsa
Entry
Catalysts
Conv. (%)
Sel. (%)
CPO
FA
THFA
Othersb
1
2
3
4
5
6
7
8
9
Pd@UiO-66(1.5wt%)
Pd@UiO-66(2.4wt%)
Pd@UiO-66(3.0wt%)
Pd@UiO-66(4.0wt%)
Pd-Co@UiO-66(1.5wt%)
Pd-Co@UiO-66(2.4wt%)
Pd-Co@UiO-66(3.0wt%)
Pd/UiO-66(2.4wt%)
100
100
100
95
100
100
100
100
100
62
76
83
92
83
96
93
75
72
1
0.5
1
1
2
0.3
1
2
31
18
12
6
14
3
4
20
19.5
6
5.5
4
1
1
0.7
2
3
Pd-Co/UiO-66(2.4wt%)
3
5.5
aReaction conditions: FUR (1.8 mmol), Pd (0.0067 mmol), H2O (20 mL), 120 °C, 3 MPa
bOthers products included 2-MF, 2-MTHF, etc.
FUR conversion [42]. With the increase of Pd content, the
CPO selectivity also increased from 62 to 92% (Entries 1–4).
Over the Pd–Co@UiO-66 catalyst, however, it increased
initially and decreased afterwards (Entries 5–7), reaching
the highest point (96%) when the Pd loading was 2.4 wt%
(Entry 6). By contrast, the CPO selectivity over Pd@UiO-66
was only 76% under the same conditions (Entry 2). It was
found that the bimetallic Pd–Co@UiO-66 catalysts exhibited
higher selectivity than monometallic Pd@UiO-66 catalysts
based on the same Pd content. Over the supported Pd/UiO-
66 catalyst prepared by the impregnation method, the CPO
selectivity was nearly the same as that of the core–shell Pd@
UiO-66 catalyst (Entries 2, 8). Surprisingly, Pd–Co/UiO-66
did not show well catalytic activity and had little impact
on the catalytic performance compared with the core–shell
counterpart (Entry 9). The reason was that the confnement
of UiO-66 structure could facilitate the formation of Pd–Co
alloy, while Pd and Co NPs on the supported catalysts were
seemingly more difcult to form the alloy due to the lack of
confnement efect within the UiO-66 framework [43].
As shown in Fig. 5a, FUR was completely converted after
6 h over the Pd@UiO-66 and the products were mainly FA
and CPO. The CPO selectivity (72%) was substantially no
longer increasing after 8 h. But the remaining FA was almost
completely converted to the undesired THFA (18% selec-
tivity). However, over the Pd–Co@UiO-66 (Fig. 5b), the
reaction was completed after 12 h and the CPO selectivity
increased with the time until it reached as high as 96% due
to the conversion of FA. It was obvious that the bimetal-
lic catalyst took more time for the complete conversion of
FUR, indicating that the catalytic activity of Pd@UiO-66
was higher than that of Pd–Co@UiO-66. Nevertheless,
almost all of the intermediate FA was converted to CPO over
the Pd–Co@UiO-66, resulting in a high CPO selectivity.
This slowdown of the reactivity would lead to a decelerated
growth of the important intermediate FA in the initial stage
which was benefcial to keep the FA at a low concentration
to suppress the production of by-products. Subsequently, it
was undoubtedly conducive to the formation of CPO [16]. It
seems that the trace Co encapsulated into Pd–Co@UiO-66
Fig. 5 Hydrogenation of FUR over Pd@UiO-66 (a) and Pd–Co@UiO-66 (b) with diferent time. Others products included 2-MF, 2-MTHF, etc.
Reaction conditions: FUR (1.8 mmol), catalysts (30 mg), H2O (20 mL), 120 °C, 3 MPa
1 3

One-Step Encapsulation of Bimetallic Pd–Co Nanoparticles Within UiO-66 for Selective Conversion…
Fig. 6 Infuence of temperature and H2 pressure on the hydrogenation
of FUR over Pd@UiO-66 (a, c) and Pd–Co@UiO-66 (b, d). Others
products included 2-MF, 2-MTHF, etc. Reaction conditions: FUR
(1.8 mmol), catalysts (30 mg), H2O (20 mL), 12 h, 3 MPa (a, b);
FUR (1.8 mmol), catalysts (30 mg), H2O (20 mL), 12 h, 120 °C (c, d)
adjusted the activity of Pd and thus restrained the hydro-
genation of FA to THFA.
UiO-66, while only about 75% CPO selectivity could be
obtained over the Pd@UiO-66 [44]. Finally, when the H2
pressure was adjusted to 3 MPa, the highest CPO selectivity
(96%) could be achieved over the bimetallic Pd–Co@UiO-
66 core–shell catalyst.
The efects of temperature (Fig. 6a, b) and H2 pressure
(Fig. 6c, d) on the two core–shell catalysts were investigated,
respectively. With the increase of temperature from 110 °C
to 150 °C, more FA underwent the rearrangement to gener-
ate CPO over the Pd@UiO-66. Instead, the selectivity of
CPO increased frst and then decreased over the bimetallic
catalysts, indicating that the appropriate increase of tempera-
ture in the reaction favored the conversion of FUR to CPO.
However, when the temperature increased above 130 °C over
both Pd@UiO-66 and Pd–Co@UiO-66 catalysts, the FUR
conversions had a slight decrease, probably resulting in the
polymerization of unreacted FUR and subsequent produc-
tion of organic polymers [40]. Meanwhile, Pd@UiO-66
achieved the highest yield of CPO at 150 °C while Pd–Co@
UiO-66 at 120 °C. It is indicated that the bimetallic catalyst
could achieve high yield under the milder reaction condition.
It is reasonably speculated that the formation of Pd–Co alloy
could afect dispersion or particle size of MNPs, thereby
improving catalytic performance [23]. However, Fig. 6c, d
demonstrated that H2 pressure had little efect on the reac-
tion. As the pressure varied from 2.0 MPa to 4.0 MPa, the
CPO selectivity remained above 90% over the Pd–Co@
The stability and leaching resistance of the catalysts were
tested by evaluating the recyclability under the same reac-
tion conditions. During each cycle of the reaction, catalysts
were washed directly with water three times and then dried
under vacuum without additional reduction [45]. As demon-
strated in Fig. 7, the core–shell catalysts maintained better
recyclability than the supported catalysts. After fve cycles,
the average selectivity of CPO over the Pd@UiO-66 was
above 75% in spite of the slight decreases in the conversion
(2%) and selectivity (5%) as illustrated in Fig. 7a. Especially,
the CPO selectivity of Pd–Co@UiO-66 nearly remained
unchanged (Fig. 7b). The XRD pattern of Pd–Co@UiO-66
catalyst had no visible change after 5th run, showing that
the crystal framework of UiO-66 remained well (Fig. 7(e)).
On the contrast, the CPO selectivities of Pd/UiO-66 and
Pd–Co/UiO-66 were signifcantly reduced by 20% and 19%,
respectively (Fig. 7c, d). After multiple cycles, not only did
more FA remain unconverted, but the undesired selectivity
of THFA gradually increased.
1 3

Y. Wang et al.
Fig. 7 Recyclability of Pd@UiO-66 (a) Pd-Co@UiO-66 (b), Pd/UiO-66 (c) and Pd–Co/UiO-66 (d). Reaction conditions: FUR (1.8 mmol), cata-
lysts (30 mg), H2O (20 mL), 120 °C, 3 MPa H2, 12 h. XRD pattern of Pd–Co@UiO-66 before and after the reaction (e)
Table 2 Pd content of catalysts measured before and after reactions
supernatant (Table 2). The results showed that the Pd con-
tents in the core–shell catalysts had no apparent change and
no detectable Pd was found in the reaction solution, which
proved the excellent leaching resistance of core–shell cata-
lysts. On the other hand, over the supported catalysts, the
Pd contents were slightly reduced, resulting in the decrease
of CPO selectivity.
Catalysts
Content of Pd(wt%)a
Before recycled
After reused
for fve times
Pd@UiO-66
Pd–Co@UiO-66
Pd/UiO-66
2.4
2.4
2.4
2.4
2.4
2.4
2.2
2.3
Pd–Co/UiO-66
4 Conclusion
aThe Pd content was tested by the ICP experiments
In summary, a bimetallic core–shell Pd–Co@UiO-66 cata-
lyst was successfully synthesized by in-situ incorporation
of bimetallic Pd–Co NPs and moderate reduction via a
temperature control program. The Pd–Co@UiO-66 catalyst
To explain the different recyclability between the
core–shell catalysts and supported ones, ICP experi-
ments were carried out using the reacted catalysts and the
1 3

One-Step Encapsulation of Bimetallic Pd–Co Nanoparticles Within UiO-66 for Selective Conversion…
18. Yang Y, Du Z, Huang Y, Lu F, Wang F, Gao J, Xu J (2013) Green
with the 2.4 wt% Pd loading and trace Co showed excellent
catalytic performance in the selective conversion of FUR
to CPO. Strikingly, 99% FUR conversion and meanwhile
96% CPO selectivity were achieved at 120 °C under 3 MPa
H2 pressure for 12 h. The high yield of CPO resulted from
the confnement of core–shell structure and bimetallic syn-
ergistic efect. Moreover, this kind of core–shell catalyst
could also exhibit excellent stability and recyclability. This
strategy of the non-noble metal partially replacing the noble
metal can not only reduce catalyst costs, but also arouse
unique properties. The research reveals that the introduction
of bimetals can broaden the applications of MNP @ MOF
composites on the efcient biomass conversion.
Chem 15:1932
19. Guo J, Xu G, Han Z, Zhang Y, Fu Y, Guo Q (2014) ACS Sustain
Chem Eng 2:2259
20. Zhu H, Zhou M, Zeng Z, Xiao G, Xiao R (2014) Korean J Chem
Eng 31:593
21. Wang Y, Sang S, Zhu W, Gao L, Xiao G (2016) Chem Eng J
299:104
22. Liu CY, Wei RP, Geng GL, Zhou MH, Gao LJ, Xiao GM (2016)
Fuel Process Technol 134:168
23. Chang L, Li Y (2017) Mol Catal 433:77
24. Hronec M, Fulajtárová K, Vávra I, Soták T, Dobročka E, Mičušík
M (2016) Appl Catal B: Environ 181:210
25. Li H, Eddaoudi M, O’Keefe M, Yaghi OM (1999) Nature 402:276
26. Chae HK, Siberio Pérez DY, Kim J, Go Y, Eddaoudi M, Matzger
AJ, Yaghi OM (2004) Nature 427:523
27. Férey G, Mellot-Draznieks C, Serre C, Millange F, Dutour J, Sur-
blé S, Margiolaki I (2005) Science 309:2040
28. Park KS, Ni Z, Côté AP, Choi JY, Huang R, Uribe-Romo FJ,
Chae HK, ÓKeefe M, Yaghi OM (2006) P Natl Acad Sci USA
103:10186
Acknowledgements This work was supported by the National Natu-
ral Science and China National Petroleum Corporation (CNPC) Joint
Foundation (No. U1662101); National Natural Science Foundation
(No: 21173030).
29. Lin L, Liu H, Zhang X (2018) Appl Surf Sci 433:602
30. Fang R, Liu H, Luque R, Li Y (2015) Green Chem 17:4183
31. Cavka JH, Jakobsen S, Olsbye U, Guillou N, Lamberti C, Bordiga
S, Lillerud K (2008) J Am Chem Soc 130:13850
32. Ramsahye NA, Gao J, Jobic H, Llewellyn PL, Yang Q, Wiersum
AD, Koza MM, Guillerm V, Serre C, Zhong CL, Maurin G (2014)
J Phys Chem C 118:27470
Compliance with Ethical Standards
Conflict of interest The authors declare no confict of interest.
33. Bai Y, Dou Y, Xie L, Rutledge W, Li J, Zhou H (2016) Chem Soc
Rev 45:2327
References
34. Chen L, Chen X, Liu H, Bai C, Li Y (2015) J Mater Chem A
3:15259
1. Klass DL (1998) Biomass for renewable energy, fuels, and chemi-
cals. Elsevier, London
35. Pastoriza-Santos I, Liz-Marzán LM (2009) Adv Funct Mater
19:679
2. Demirbaş A (2001) Energ Convers Manage 42:1357
3. Corma A, Iborra S, Velty A (2007) Chem Rev 107:2411
4. Lange JP, Van Der Heide E, Van Buijtenen J, Price R (2012)
Chemsuschem 5:150
36. Wu F, Lin L, Liu H, Wang H, Qiu J, Zhang X (2017) J Membrane
Sci 544:342
37. Zheng S, Yang P, Zhang F, Chen D, Zhu W (2017) Chem Eng J
328:977
5. Li JQ (2001) Chem Eng J 1:338
38. Krawczyk M, Sobczak JW (2004) Appl Surf Sci 235:49
39. Li H, Zhu Z, Zhang F, Xie S, Li H, Li P, Zhou X (2011) ACS Catal
1:1604
6. Yan K, Wu G, Lafeur T, Jarvis C (2014) Renew Sust Energ Rev
38:663
7. Li X, Jia P, Wang T (2016) ACS Catal 6:7621
8. Pushkarev VV, Musselwhite N, An K, Alayoglu S, Somorjai GA
(2012) Nano Lett 12:5196
40. Yin D, Ren H, Li C, Liu J, Liang C (2018) Chinese J Catal 39:319
41. Hronec M, Fulajtárova K, Mičušík M (2013) App Catal A: Gen
468:426
9. Biradar NS, Hengne AM, Birajdar SN, Niphadkar PS, Joshi PN,
Rode CV (2012) ACS Sustain Chem Eng 2:272
10. Taber DF (1977) J Am Chem Soc 99:3513
11. Tiziana G, Emanuela E, Emanuela M, Rosanna DP, Carmelo M,
Rosaria M, Placido B, Salvatore C (2008) Shock 30:142
12. Nagashima O, Sato S, Takahashi R, Sodesawa T, Akashi T (2006)
Appl Catal A: Gen 312:175
42. Yu W, Porosof MD, Chen JG (2012) Chem Rev 112:5780
43. Chen L, Chen H, Luque R, Li Y (2014) Chem Sci 5:3708
44. Maheswari S, Karthikeyan S, Murugan P, Sridhar P, Pitchumani
S (2012) Phys Chem Chem Phys 14:9683
45. Hronec M, Katarina F, Liptaj T (2012) Appl Catal A: Gen 437:104
Publisher’s Note Springer Nature remains neutral with regard to
jurisdictional claims in published maps and institutional afliations.
13. Zhan BZ, Thompson A (2004) Tetrahedron 13:2917
14. Takehira K, Hayakawa T, Orita H, Shimizu M (1989) J Mol Catal
53:15
15. Hronec M, Fulajtarová K (2012) Catal Commun 24:100
16. Zhang GS, Zhu MM, Zhang Q, Liu YM, He HY, Gao Y (2016)
Green Chem 18:2155
17. Liu X, Zhang B, Fei B, Chen X, Zhang J, Mu X (2017) Faraday
Discuss 202:79
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