Porous Zr–Thiophenedicarboxylate Hybrid for Catalytic Transfer Hydrogenation of Bio-Based Furfural to Furfuryl Alcohol

Article abstract of DOI:10.1007/s10562-019-02748-0

Furfural (FAL) is one of the most important biomass-derived platform compounds. The catalytic transformation of FAL was investigated with three porous Zr–thiophenedicarboxylate hybrids for the production of furfuryl alcohol (FOL). Three Zr-based catalysts, including DUT-67(Zr), DUT-68(Zr) and DUT-69(Zr) were synthesized through a facile assembly of 2,5-thiophenedicarboxylate acid with ZrCl₄ using the acetic acid as a modulator under hydrothermal conditions. These catalysts were also characterized using FT-IR, XRD, SEM, TEM, N₂ adsorption–desorption, XPS and TG. The specific surface area of the DUT-69(Zr) is smaller than that of the DUT-68(Zr) and slightly larger than that of the DUT-67(Zr), but it has a relatively large pore volume and pore diameter. Although all three catalysts showed excellent catalytic activity towards the catalytic transfer hydrogenation of FAL into FOL, the DUT-69(Zr) material has slightly higher catalytic activity than the other two catalysts. Besides, considering the cost of catalyst preparation, the DUT-69(Zr) material was used as the optimal catalyst and studied in detail. A high FOL yield of 92.2% at 95.9% FAL conversion was achieved at 120?°C for 4?h over DUT-69(Zr). Meanwhile, the DUT-69(Zr) could be reused more than six times with a minor decrease in catalytic activity. Finally, a plausible mechanism for catalytic transfer hydrogenation of carbonyl compounds to produce corresponding alcohols was presented based on the results of the experiments and previous reports. Graphical Abstract: [Figure not available: see fulltext.].

Full text of DOI:10.1007/s10562-019-02748-0

Catalysis Letters
https://doi.org/10.1007/s10562-019-02748-0
Porous Zr–Thiophenedicarboxylate Hybrid for Catalytic Transfer
Hydrogenation of Bio-Based Furfural to Furfuryl Alcohol
Tao Wang1 · Aiyun Hu1 · Guangzhi Xu1 · Chen Liu1 · Haijun Wang1 · Yongmei Xia2
Received: 18 January 2019 / Accepted: 11 March 2019
© Springer Science+Business Media, LLC, part of Springer Nature 2019
Abstract
Furfural (FAL) is one of the most important biomass-derived platform compounds. The catalytic transformation of FAL
was investigated with three porous Zr–thiophenedicarboxylate hybrids for the production of furfuryl alcohol (FOL). Three
Zr-based catalysts, including DUT-67(Zr), DUT-68(Zr) and DUT-69(Zr) were synthesized through a facile assembly of
2,5-thiophenedicarboxylate acid with ZrCl4 using the acetic acid as a modulator under hydrothermal conditions. These cata-
lysts were also characterized using FT-IR, XRD, SEM, TEM, N2 adsorption–desorption, XPS and TG. The specifc surface
area of the DUT-69(Zr) is smaller than that of the DUT-68(Zr) and slightly larger than that of the DUT-67(Zr), but it has a
relatively large pore volume and pore diameter. Although all three catalysts showed excellent catalytic activity towards the
catalytic transfer hydrogenation of FAL into FOL, the DUT-69(Zr) material has slightly higher catalytic activity than the
other two catalysts. Besides, considering the cost of catalyst preparation, the DUT-69(Zr) material was used as the optimal
catalyst and studied in detail. A high FOL yield of 92.2% at 95.9% FAL conversion was achieved at 120 °C for 4 h over DUT-
69(Zr). Meanwhile, the DUT-69(Zr) could be reused more than six times with a minor decrease in catalytic activity. Finally,
a plausible mechanism for catalytic transfer hydrogenation of carbonyl compounds to produce corresponding alcohols was
presented based on the results of the experiments and previous reports.
Graphical Abstract
Keywords Furfural · Carbonyl compounds · Furfuryl alcohol · Catalytic transfer hydrogenation · Zr–
thiophenedicarboxylate hybrid · DUT-69(Zr)
Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s10562-019-02748-0) contains
supplementary material, which is available to authorized users.
Extended author information available on the last page of the article
Vol.:(0123456789)
1 3

T. Wang et al.
For the last few years, it has been a more reasonable
approach for the CTH of FAL to produce FOL by using
alcohols as the hydrogen source and solvent. These alcohols
are safe and abundant. More importantly, these reactions
could be carried out in a relatively simple device without
dangerous hydrogen. The CTH procedure with alcohols
depend on Meerwein–Ponndorf–Verley (MPV) reduction
reaction, where carbonyl compounds were converted to cor-
responding alcohols [30]. Recently, various catalytic sys-
tems have been developed for the conversion of FAL–FOL.
For example, earth-abundant metal nanoparticles, such as
Al–Zr@Fe3O4, B–Al2O3, Cu/MgO–Al2O3, γ-Fe2O3@HAP,
NiFe2O4, Fe–L1/C-800, Co/SBA-15 and NiFe/SiO2 were
used as catalysts to obtain high yield of FOL [31–38]. In
addition, Zr- and Hf-based phosphate hybrid materials, such
as Zr-PhyA, ZrPN and PhP-Hf (1:1.5) had been prepared
to catalyze the CTH of FAL–FOL efciently [39–41]. In
particular, several Zr- and Hf-based metal–organic compos-
ites showed pronounced catalytic performances in the MPV
reaction [42–46]. Zirconium and hafnium have multi-coor-
dination sites. In addition to coordination with large organic
ligands (e.g. 1,4-benzenedicarboxylic acid, 1,3,5-benzenet-
ricarboxylic acid and 2,5-furandicarboxylic acid) [42, 44,
46], Zr4+ and Hf4+combine some small solvent molecules
to meet their coordination number requirements, such as
water, ethanol, DMF, etc. When these guest molecules are
removed, the vacancies left can produce permanent pores.
These combined factors contribute to their porosity and high
specifc surface area, which can facilitate the efective dif-
fusion of reactant molecules and provide a large number
of easily accessible catalytic active sites, resulting in their
highly efcient catalytic performances. Fortunately, these
catalysts exhibited robustness, thermal and chemical stabil-
ity owing to the higher co-ordination number of Zr or Hf in
their structure.
1 Introduction
The massive depletion of non-renewable fossil fuels, such
as oil, coal and natural gas, has caused serious environ-
mental pollution problems, which is irreconcilable with
people’s growing health and environmental awareness
[1–3]. In addition to the unstable factors of oil price and
supply worldwide, it is of great practical signifcance to
explore sustainable resources in the long term. Biomass,
as one of the potential substitutes of fossil fuels, has been
identifed as an ideal feedstock for the production of liquid
fuels and high-valued chemicals [4–6]. In industry, Fur-
fural (FAL) can be produced by direct catalytic degrada-
tion of lignocellulose biomass (e.g. corncob and straw)
with dilute acid. It has been considered as one of the most
significant biomass-based platform compounds [7–9].
FAL is a cheap, readily available renewable resource, and
its downstream products are not only rich but also have
high economic value [10, 11]. It has aldehyde functional
groups, which can be oxidized, hydrogenated and conden-
sated to produce various derivatives because of its active
chemical properties.
Hydrogenation reaction of FAL is a very important
technology for production of high-added value products
like furfuryl alcohol, tetrahydrofurfural, tetrahydrofurfuryl
alcohol, furan, 2-methylfuran [12–16]. Among these com-
pounds, furfuryl alcohol (FOL) is recognized as a momen-
tous intermediate that can be prepared various products
such as resins, adhesives, lubricants and fbers [17, 18].
Therefore, the conversion of FAL–FOL is considered to be
one of the key steps in the transformation of biomass. Not
only can this solve the technical bottleneck problem that
restricts the development of furfural industrial chain, but
also has far-reaching signifcance to the national economic
green and sustainable development strategy [19, 20].
Concerning the synthesis of FOL, two main methods have
been reported. Cu–Cr oxide was widely used as a commer-
cial catalyst for the production of FOL [21]. This method
may achieve high selectivity of FOL, but high toxicity of
Cr6+ can lead to serious environmental pollution after the
ultima treatment of the catalyst [22]. Therefore, research-
ers focus on exploring the use of chromium-free catalysts
in the reaction of FAL to produce FOL. These reactions,
which were catalyzed by precious metal catalysts such as
Re, Pt, Ru and Pd [23–27], generally were carried out in
the atmosphere of external molecular hydrogen. Although
these catalysts showed excellent catalytic activities in the
process from FAL to FOL via catalytic transfer hydrogena-
tion (CTH). The shortcomings of high cost, fammable and
explosive nature of hydrogen limited their wide applications
[28, 29]. Consequently, we are looking forward to fnding
an appropriate hydrogen source for the synthesis of FOL.
Similar to the structure of 2,5-furandicarboxylic acid that
is used as an organic ligand for MOFs preparation [42, 46],
2,5-thiophenedicarboxylate acid (H2tdc) also contains two
-COOH groups at the same position, making it conducive to
the manufacture of MOFs. In the present work, three porous
Zr–thiophenedicarboxylate hybrids, including DUT-67(Zr),
DUT-68(Zr) and DUT-69(Zr) were obtained through a fac-
ile assembly of H2tdc with ZrCl4 using the acetic acid as a
modulator under hydrothermal conditions [47, 48]. Difer-
ent materials were prepared by varying the thermal reaction
time, reaction solvent and the proportion between materi-
als, resulting in the diference in their physical properties.
Among the three Zr-based catalysts, the specifc surface area
of the DUT-69(Zr) is smaller than that of the DUT-68(Zr)
and slightly larger than that of the DUT-67(Zr), but it has
a relatively large pore volume and pore diameter. It is well
known that the specifc surface area and pore size of the
catalyst afect the catalytic activity of the catalyst. Although
1 3

Porous Zr–Thiophenedicarboxylate Hybrid for Catalytic Transfer Hydrogenation of Bio-Based…
all three catalysts showed excellent catalytic activity on the
CTH of FAL into FOL, DUT-69(Zr) has a slightly higher
activity than the other two catalysts and is cheaper to pre-
pare. Based on the above-mentioned factors, the DUT-69(Zr)
material was used as the most ideal catalyst and studied in
detail. To the best of our knowledge, the application of
DUT-69(Zr) in CTH reaction had never been reported. The
optimal reaction conditions were investigated systematically
and a plausible reaction mechanism was put forward based
on the fndings acquired from the experiments and previous
reports.
Then, 1.29 g (7.50 mmol) of H2tdc was added to the mix-
ture and sonicated for another 10 min. Thereafter, 55 mL
(915 mmol) of acetic acid was added to the above mixture
and sonicated additional 20 min. After that, the resulting
mixture was transferred to a 200 mL Tefon-lined pres-
sure reactor and heated in an oven for 72 h at 120 °C.
Finally, the generated precipitates were fltered, washed
initially with DMF and then with ethanol twice, and dried
at 120 °C under vacuum conditions for 12 h.
2.2.3 Preparation of DUT-69(Zr)
2 Experimental
In a typical procedure, 0.69 g (3 mmol) of ZrCl4 was frst
dissolved in DMF (150 mL) by sonication for 20 min.
Then, 0.52 g (3 mmol) of H2tdc was added to the mix-
ture and sonicated for another 10 min. Thereafter, 9 mL
(150 mmol) of acetic acid was added to the above mixture
and sonicated additional 20 min. After that, the reaction
mixture was transferred to a 200 mL Tefon-lined pres-
sure reactor and heated in an oven for 12 h at 120 °C.
Finally, the generated precipitates were fltered, washed
initially with DMF and then with ethanol twice, and dried
at 120 °C under vacuum conditions for 12 h.
2.1 Chemicals
Furfuryl alcohol and ZrCl4 (98%) were purchased from
Aladdin Reagent Co. Ltd. (Shanghai, China). 2,5-thiophen-
edicarboxylic acid (H2tdc, 98%) was supplied by Adamas-
beta. N,N-dimethylformamide (DMF), acetic acid (99.7%),
1-methyl-2-pyrrolidone (NMP), zirconium dioxide, fur-
fural, ethanol, 2-propanol, naphthalene and other chemicals
were obtained from Sinopharm Chemical Reagent Co. Ltd.
(Shanghai, China). Commercial chemicals were of analytical
grade and used directly without further purifcation. Deion-
ized water was produced by using a laboratory water-purif-
cation system (RO DI Digital plus).
2.3 Catalyst Characterization
FT-IR measurements of all the catalysts were recorded
using a Nicolet iS50 FT-IR spectrometer with the KBr pel-
let technique in the range of 4000–400 cm−1 at room tem-
perature. Powder X-ray difraction (XRD) patterns were
carried out on a Bruker D2 Phaser instrument employ-
ing Cu Kα radiation (λ = 0.15406 nm) in the 2θ range of
4°–80° with a step size of 0.01° at 30 kV and 10 mA.
SEM images of the as-prepared samples were performed
on a HITACHI S-4800 feld-emission scanning electron
microscope at 3 KV. All the catalysts were coated with a
thin layer of gold to prevent the accumulation of negative
charges. TEM images of all the samples were recorded
by using a JEM-2100plus with an accelerating voltage
of 200 kV. Thermal gravimetric analysis (TGA) of the
samples was performed on a TGA/DSC1/1100SF thermal
analyzer. The analysis started at 50 °C with a heating rate
of 10 °C/min until 700 °C in nitrogen atmosphere (50 mL/
min). Texture properties including specifc surface areas,
pore volumes and pore diameters were tested at − 196 °C
using the Micromeritics ASAP 2020 msystem, the samples
were degassed at 120 °C for 12 h in a vacuum before N2
adsorption. The chemical composition and the chemical
state of the elements in the samples were determined using
a Thermo Scientifc Escalab 250Xi X-ray photoelectron
spectrometer.
2.2 Catalyst Preparation
Three porous Zr–thiophenedicarboxylate hybrids were syn-
thesized by solvothermal method with appropriate modif-
cations according to previously reported procedures [47].
2.2.1 Preparation of DUT-67(Zr)
In a typical procedure, 0.92 g (4 mmol) of ZrCl4 was frst
dissolved in the mixture of DMF (50 mL) and NMP (50 mL)
by sonication for 20 min. Then, 0.44 g (2.68 mmol) of H2tdc
was added to the mixture and sonicated for another 10 min.
Thereafter, 28 mL (468 mmol) of acetic acid was added to
the above mixture and sonicated additional 20 min. After
that, the resulting mixture was transferred to a 200 mL
Tefon-lined pressure vessel and heated in an oven for 48 h
at 120 °C. Finally, the generated precipitates were fltered,
washed initially with DMF and then with ethanol twice, and
dried at 120 °C under vacuum conditions for 12 h.
2.2.2 Preparation of DUT-68(Zr)
In a typical procedure, 1.15 g (5 mmol) of ZrCl4 was frst
dissolved in DMF (125.0 mL) by sonication for 20 min.
1 3

T. Wang et al.
2.4 Catalytic Tests
3 Results and Discussion
In a typical experiment, the cylindrical stainless steel high-
pressure vessel was loaded with FAL (1 mmol), 2-propanol
(5 mL) and the catalyst (0.1 g), and then heated at a certain
designated temperature for the desired reaction time with
magnetic stirring. Upon completion, the resulting liquid
products were analyzed quantitatively by gas chromatogra-
phy (GC 9790 II) using naphthalene as the internal stand-
ard, and identifcation of the products was done by GC-MS
(GCMS-QP2010 Ultra). The yield of FOL, the conversion
of FAL and the selectivity to FOL were calculated on the
basis of the following formula.
3.1 Catalyst Characterization
The prepared DUT-69(Zr) was characterized by FT-IR,
XRD, SEM, TEM, N2 adsorption–desorption isotherm,
XPS and TGA techniques. The FT-IR spectrum of the
DUT-69(Zr) was shown in Fig. 1a. It can be seen that DUT-
69(Zr) displayed the characteristic symmetric (1393 cm−1)
and asymmetric vibrations (1500–1700 cm−1) of carboxylate
anions [49]. The spacing between these two peaks is about
190 cm−1, indicating that the coordination mode of H2tdc to
Zr is bridging [43, 50]. By comparison, FT-IR spectrum of
H2tdc showed a splitting of approximately 250 cm−1 between
these two peaks, which further confrmed the tight combina-
tion between Zr and carboxyl groups of H2tdc. The powder
XRD pattern of the DUT-69(Zr) was shown in Fig. 1b. It
has been clearly observed that the DUT-69(Zr) material is
amorphous owing to a few wide difraction peaks, despite
one sharp difraction peak at 2θ=8.6°, which is analogous
Final moles of FOL
Yield =
× 100%
(1)
Initial moles of FAL
Initial moles of FAL − Final moles of FAL
Conversion =
× 100%
Initial moles of FAL
(2)
Final moles of FOL
Selectivity =
× 100%
Initial moles of FAL − Final moles of FAL
(3)
Fig. 1 Characterization of the as-prepared DUT-69(Zr) by a FT-IR spectra, b Powder XRD pattern, c SEM image and d TEM image
1 3

Porous Zr–Thiophenedicarboxylate Hybrid for Catalytic Transfer Hydrogenation of Bio-Based…
to difraction of Zr-FDCA-T [42]. Especially, the SEM and
TEM images indicated that nanoparticles (100–120 nm)
of the DUT-69(Zr) are slightly aggregated (Fig. 1c, d).
As shown in Fig. 2a, the N2 adsorption–desorption iso-
therm of the DUT-69(Zr) belonged to type III mode with
a large amount of adsorption between the relative pressure
of 0.75–1.0. In addition, the DUT-69(Zr) was porous with
mesoporous centered about 12.0 nm, and the specifc sur-
face area and pore volume were 158.1 m2/g and 0.60 cm3/g,
respectively. This may increase the accessibility of cata-
lytic sites for the reactant compared with ZrO2 [51, 52]. We
inspected the local environment of Zr species in DUT-69(Zr)
and ZrO2 by the Zr 3d XPS. As shown in Fig. 2b, the binding
energies of Zr 3d in DUT-69(Zr) were higher in comparison
with ZrO2, which illustrated a higher positive charge on the
Zr atoms in DUT-69(Zr) and led to a stronger Lewis acidity
of Zr. The higher Lewis acidity of Zr species was helpful to
improve the performance of DUT-69(Zr) catalyst. TG analy-
sis of the catalyst was performed to gain an insight into the
thermal stability of the DUT-69(Zr). As shown in Fig. S1,
the weight loss in the temperature range from 350 to 500 °C
could be ascribed to the elimination of TDC ligand from
the structure, thus resulting in the destruction of catalyst
structure and the formation of zirconium oxide [47, 48]. It
proved that the DUT-69(Zr) catalyst had pronounced sta-
bility at the reaction temperatures (below 140 °C). DUT-
67(Zr) and DUT-68(Zr) catalysts were also synthesized and
characterized to explore their diferences. No obvious dif-
ferences among DUT-67(Zr), DUT-68(Zr) and DUT-69(Zr)
were found from FT-IR spectra and XRD patterns (Figs. S2,
S3). The SEM images demonstrate that they have diferent
sizes of nanoparticles (Fig. S4). The particle size of DUT-
67(Zr) is below 100 nm, while those of DUT-68(Zr) and
DUT-69(Zr) are relatively larger. The specifc surface area
of the DUT-69(Zr) is smaller than that of the DUT-68(Zr)
and slightly larger than that of the DUT-67(Zr), but it has a
relatively large pore volume and pore diameter (Table S1).
3.2 Catalytic Activity of Various Catalysts
for the CTH Reaction of FAL
In the initial experiment, we chose FAL as the model sub-
strate to examine the catalytic performance of various cata-
lysts for the formation of FOL through CTH reactions. As
summarized in Table 1, it can be seen that the reaction could
not be conducted in the absence of any catalysts (Table 1,
entry 1). All the synthesized porous Zr–thiophenedicarbo-
xylate hybrids catalysts showed pronounced catalytic activ-
ity on the CTH of FAL into FOL (Table 1, entries 2–4).
Especially, the prepared DUT-69(Zr) catalyst showed the
highest activity with the FOL yield of 92.2% at 120 °C with
Table 1 CTH reaction of FAL to produce FOL catalyzed by various
catalysts.
Entry Catalyst
Conversion (%) Yield (%) Selectivity (%)
1
2
3
4
5
6
7
None
0
0
0
DUT-69(Zr) 95.9
DUT-68(Zr) 91.6
DUT-67(Zr) 92.7
H2tdc
ZrCl4
ZrO2
92.2
87.7
89.5
0
1.1
7.1
96.1
95.7
96.5
0
5.4
42.8
8.8
20.2
16.6
Reaction conditions: 0.1 g catalyst, 1 mmol FAL, 5 mL 2-propanol,
reaction temperature=120 °C, reaction time=4 h
Fig. 2 Characterization of the as-prepared DUT-69(Zr) by a N2 adsorption–desorption isotherms and b Zr 3d XPS spectra
1 3

T. Wang et al.
a reaction time of 4 h (Table 1, entry 2). However, H2tdc
alone, which possessed two carboxyl functional groups, was
not active for the production of FOL (Table 1, entry 5). This
showed that the Brønsted acidity of the carboxylic acid had
no catalytic performance for the CTH reaction of FAL–FOL.
The precursor ZrCl4 used for Zr–thiophenedicarboxylate
hybrids synthesis yielded less than 2% of FOL (Table 1,
entry 6). In addition, the commercial ZrO2 showed inferior
performance with a FOL yield of 7.1% (Table 1, entry 7).
These results revealed that three porous Zr–thiophenedicar-
boxylate hybrids could be used to catalyze the CTH of FAL
and the DUT-69(Zr) prepared in this study was an excellent
catalyst for CTH of FAL.
3.3 Efect of Catalyst Amount
The efect of the amount of DUT-69(Zr) on the transfor-
mation of FAL into FOL was investigated in 2-propanol at
120 °C with a reaction time of 4 h (Fig. 3). The amount of
catalyst plays a key role in the CTH of FAL, where more
DUT-69(Zr) could increase the conversion of FAL and the
yield of FOL at the beginning. FAL conversion and FOL
yield substantially increase from 67.2 and 65.3% to 86.0
and 83.3% respectively when the amount of DUT-69(Zr)
increases from 0.025 to 0.05 g. Greater than 95% conver-
sion of FAL and 92% yield of FOL were obtained when
the DUT-69(Zr) dosage was 0.1 g. After which, FOL yield
and selectivity declined slightly with a catalyst dosage of
0.125 g, largely because more catalytic sites promoted the
production of more by-products including 5-methylfurfural
and 2-acetylfuran as revealed from GC-MS spectra (Fig. S7),
these by-products are observed in the CTH of FAL–FOL
in other literature [53]. Given the above, 0.1 g of the cat-
alyst would be an appropriate amount under our reaction
conditions.
3.4 Efect of Reaction Temperature and Time
Figure 4 showed the efect of the reaction temperature and
time on FOL synthesis. It was clear that the reaction tem-
perature and time infuenced the activity of the DUT-69(Zr)
catalyst. Especially in the time range of 1–2 h, the FAL
Fig. 3 Efect of catalyst amount on the CTH reaction of FAL to pro-
duce FOL. Reaction conditions: 1 mmol FAL, 5 mL 2-propanol, reac-
tion temperature=120 °C, reaction time=4 h
Fig. 4 Efect of reaction temperature and time on the FOL yield (a) and FAL conversion (b). Reaction conditions: 0.1 g catalyst, 1 mmol FAL,
5 mL 2-propanol
1 3

Porous Zr–Thiophenedicarboxylate Hybrid for Catalytic Transfer Hydrogenation of Bio-Based…
conversion and FOL yield greatly increased with increasing
temperature. However, FOL yield hardly relied on the reac-
tion temperature above 120 °C and reaction time surpass-
ing 4 h. GC detection showed peak enhancement of side-
products at higher temperatures and longer times. From the
standpoint of efciency, the optimum reaction temperature
and reaction time were selected at 120 °C and 4 h, respec-
tively, under our reaction conditions.
was also studied. As shown in Fig. 6b, it was observed that
DUT-69(Zr) could be reused more than six cycles with only
a slight decline in its catalytic performance. Meanwhile, the
recovered DUT-69(Zr) after six cycles was also character-
ized by SEM, XRD, FT-IR and TG (Fig. S8), and the results
indicated that the structures of the catalyst had not changed
signifcantly after reused for six cycles. These results dem-
onstrated that the as-prepared DUT-69(Zr) was stable under
the studied reaction conditions.
The CTH of FAL has been reported to be pseudo-frst
order with regard to FAL concentration [54]. As shown in
Fig. 5a, increasing the reaction temperature from 110 to
130 °C promoted FAL conversion, leading to an elevated
reaction rate constant (k) from 0.01151 to 0.01822 min−1,
matching well with the above analysis results (Fig. 4). From
an Arrhenius plot of the data (Fig. 5b), the activation energy
(Ea) of CTH of FAL–FOL over DUT-69(Zr) in 2-propanol
was evaluated to be 29.5 kJ/mol, which is close to and even
lower than values previously reported in literature [34, 35,
54]. The results demonstrate that the as-synthesized DUT-
69(Zr) is highly active in the CTH of FAL–FOL.
3.6 Catalytic Efect of DUT‑69(Zr) on Diferent
Substrates
Delighted by the remarkable activity of the catalyst for the
transformation of FAL, we also tested CTH of other car-
bonyl compounds catalyzed by the DUT-69(Zr) using 2-pro-
panol as the solvent (Table 2). The results demonstrated that
the DUT-69(Zr) could also exhibited good performance
for all selected aldehydes and ketones. Biomass-derived
5-hydroxymethyl furfural and 5-methyl furfural yielded
86.2% 2,5-dihydroxymethylfuran and 91.5% 5-methyl fur-
furyl alcohol respectively, although this required a longer
reaction time and relatively higher reaction temperature
(Table 2, entries 2 and 3). Compared with benzaldehyde,
the reaction conditions of acetophenone are more demand-
ing, which resulted from the steric hindrance and electron-
donating properties of methyl (Table 2, entries 4 and 5)
[51]. Especially, the C=O bond of cinnamaldehyde could
be selectively reduced, while the C=C bond outside the
benzene ring was retained (Table 2, entry 6). Hence, the
DUT-69(Zr) catalyst exhibited good universality for CTH
of carbonyl compounds.
3.5 Heterogeneity and Reusability of the Catalyst
To examine the heterogeneity of DUT-69(Zr), the catalyst
was removed from the reaction mixture via fltering after
the reaction was carried out at 120 °C for 2 h, and the reac-
tion was continued to 5 h in the absence of catalyst under
the identical reaction conditions to observe if the yield of
FOL further increased. As shown in Fig. 6a, it was found
that FOL yield remained unchanged around 76.5% after
removing DUT-69(Zr), confrming that there was no loss of
active sites in DUT-69(Zr) and the reaction was conducted
under heterogeneous catalyst. The reusability of the catalyst
Fig. 5 –ln(1−Xa) versus time (min) (a) and ln(k) versus reciprocal of reaction temperature (b) in CTH of FAL over DUT-69(Zr) (where
Xa=FAL conversion). Reaction conditions: 0.1 g catalyst, 1 mmol FAL, 5 mL 2-propanol, reaction time=0.5–5 h
1 3

T. Wang et al.
Fig. 6 a Time-yield plots for CTH reaction of FAL to FOL with
DUT-69(Zr) (black line) or removing DUT-69(Zr) after 2 h (red line)
and b reusability of the DUT-69(Zr). Reaction conditions: 1 mmol
FAL, 5 mL 2-propanol, 0.1 g catalyst, reaction temperature=120 °C,
reaction time=3 h
Table 2 CTH of diferent carbonyl compounds to produce corresponding alcohols catalyzed by DUT-69(Zr)
Reaction conditions: 1 mmol substrate, 0.1 g DUT-69(Zr), and 5 mL 2-propanol
It was reported that acidic and basic sites in the catalysts
3.7 Mechanism Analysis
were critical for their high performance in MPV reduction
[39, 51]. In Zr-based MOFs catalysts, the acid and basic
sites derived from the Zr4+ and O2− (carboxylate groups),
respectively [42–44]. Typically, a pair of acid-base sites
(Zr4+–O2−) helps to adsorb 2-propanol onto DUT-69(Zr)
and could result in the generation of corresponding alkoxide
In combination with the experimental results and some pre-
vious reports [40, 41, 55–58], we put forward a possible
reaction mechanism of the DUT-69(Zr)-catalyzed hydrogen
transfer reaction of carbonyl compounds to produce corre-
sponding alcohols based on MPV reduction (Scheme 1).
1 3

Porous Zr–Thiophenedicarboxylate Hybrid for Catalytic Transfer Hydrogenation of Bio-Based…
Scheme 1 Possible mechanism
for CTH of carbonyl compounds
to produce corresponding alco-
hols catalyzed by DUT-69(Zr)
Acknowledgements This work was fnancial supported by the MOE
and hydrogen by dissociation. Simultaneously, the carbonyl
groups in reactant molecules were activated by acidic Zr4+
species, thus leading to six-link intermediates to generate
the corresponding products and acetone.
& SAFEA for the 111 Project (B13025).
Compliance with Ethical Standards
Conflict of interest All authors declare that they have no conficts of
interest.
4 Conclusions
In summary, three porous Zr–thiophenedicarboxylate
hybrids, namely DUT-67(Zr), DUT-68(Zr), and DUT-69(Zr)
were constructed through a facile assembly of 2,5-thiophen-
edicarboxylate acid with ZrCl4 using the acetic acid as a
modulator under hydrothermal conditions. These three dif-
ferent materials were prepared by varying the thermal reac-
tion time, reaction solvent and the proportion between mate-
rials. All three catalysts were verifed to be highly efcient
for the conversion of FAL into FOL. Considering the cost
of catalyst preparation, the DUT-69(Zr) material was used
as the most ideal catalyst and systematically studied. In the
presence of DUT-69(Zr), 95.9% FAL conversion and 92.2%
FOL yield were attained under optimal reaction conditions.
Moreover, it has been proved that the DUT-69(Zr) was a
heterogeneous catalyst in the reaction process, and the high
performance of DUT-69(Zr) might be attributed to the syn-
ergistic efect the Lewis acid sites (originating from Zr4+)
and basic sites (resulting from O2− in carboxylate groups).
Besides, DUT-69(Zr) could be reused more than six suc-
cessive cycles with minor decrease of catalytic activity. In
addition, a possible reaction mechanism of the DUT-69(Zr)
catalyst for the CTH reactions of carboxyl compounds was
proposed. We believe that the prepared porous Zr–thiophen-
edicarboxylate hybrids have great potential for application
in the CTH of carbonyl compounds, whether or not they are
derived from biomass.
References
1. Climent MJ, Corma A, Iborra S (2014) Conversion of biomass
platform molecules into fuel additives and liquid hydrocarbon
fuels. Green Chem 16:516–547
2. Besson M, Gallezot P, Pinel C (2014) Conversion of biomass into
chemicals over metal catalysts. Chem Rev 114:1827–1870
3. Zhou CH, Xia X, Lin CX, Tong DS, Beltramini J (2011) Catalytic
conversion of lignocellulosic biomass to fne chemicals and fuels.
Chem Soc Rev 40:5588–5617
4. Chatterjee C, Pong F, Sen A (2015) Chemical conversion path-
ways for carbohydrates. Green Chem 17:40–71
5. Binder JB, Raines RT (2009) Simple chemical transformation of
lignocellulosic biomass into furans for fuels and chemicals. J Am
Chem Soc 131:1979–1985
6. Dutta S, Pal S (2014) Promises in direct conversion of cellulose
and lignocellulosic biomass to chemicals and fuels: combined
solvent-nanocatalysis approach for biorefnary. Biomass Bioen-
ergy 62:182–197
7. Li XD, Jia P, Wang TF (2016) Furfural: a promising platform
compound for sustainable production of C4 and C5 chemicals.
ACS Catal 6:7621–7640
8. Yan K, Wu GS, Lafeur T, Jarvis C (2014) Production, properties
and catalytic hydrogenation of furfural to fuel additives and value-
added chemicals. Renew Sust Energy Rev 38:663–676
9. Gallezot P (2012) Conversion of biomass to selected chemical
products. Chem Soc Rev 41:1538–1558
10. Nandi S, Saha A, Patel P, Khan NH, Kureshy RI, Panda AB
(2018) Hydrogenation of furfural with nickel nanoparti-
cles stabilized on nitrogen-rich carbon core-shell and its
1 3

T. Wang et al.
transformations for the synthesis of γ-valerolactone in aqueous
conditions. ACS Appl Mater Interfaces 10:24480–24490
11. Lange JP, van der Heide E, van Buijtenen J, Price R (2012)
Furfural-a promising platform for lignocellulosic biofuels.
ChemSusChem 5:150–166
29. Vaidya PD, Mahajani VV (2013) Kinetics of liquid-phase hydro-
genation of furfuraldehyde to furfuryl alcohol over a Pt/C cata-
lyst. Ind Eng Chem Res 42:3881–3885
30. Corma A, Domine ME, Nemeth L, Valencia S (2002) Al-free
Sn-beta zeolite as a catalyst for the selective reduction of car-
bonyl compounds (Meerwein-Ponndorf-Verley Reaction). J Am
Chem Soc 124:3194–3195
12. Yan YX, Bu CY, He Q, Zheng ZJ, Ouyang J (2018) Efcient
bioconversion of furfural to furfuryl alcohol by Bacillus coagu-
lans NL01. RSC Adv 8:26720–26727
31. He J, Li H, Riisager A, Yang S (2017) Catalytic transfer hydro-
genation of furfural to furfuryl alcohol with recyclable Al-Zr@
Fe mixed oxides. ChemCatChem 9:1–10
13. Rodiansono R, Khairi S, Hara T, Ichikuni N, Shimazu S (2012)
Highly efcient and selective hydrogenation of unsaturated car-
bonyl compounds using Ni-Sn alloy catalysts. Catal Sci Technol
2:2139–2145
32. López-Asensio R, Cecilia JA, Jiménez-Gómez CP, García-
Sancho C, Moreno-Tost R, Maireles-Torres P (2018) Selec-
tive production of furfuryl alcohol from furfural by catalytic
transfer hydrogenation over commercial aluminas. Appl Catal
A 556:1–9
14. Huang RJ, Cui QQ, Yuan QQ, Wu HH, Guan YJ, Wu P (2018)
Total hydrogenation of furfural over Pd/Al2O3 and Ru/ZrO2
mixture under mild conditions: essential role of tetrahydrofur-
fural as an intermediate and support efect. ACS Sustain Chem
Eng 6:6957–6964
33. Chen H, Ruan HH, Lu XL, Fu J, Langrish T, Lu XY (2018) Ef-
cient catalytic transfer hydrogenation of furfural to furfuryl alco-
hol in near-critical isopropanol over Cu/MgO-Al
Catal 445:94–101
15. Wang CT, Liu ZQ, Wang L, Dong X, Zhang J, Wang GX, Han
SC, Meng XJ, Zheng AM, Xiao FS (2018) Importance of zeolite
wettability for selective hydrogenation of furfural over Pd@
Zeolite catalysts. ACS Catal 8:474–481
2O3 catalyst. Mol
34. Wang F, Zhang ZH (2017) Catalytic transfer hydrogenation of fur-
fural into furfuryl alcohol over magnetic γ–Fe2O3@HAP Catalyst.
ACS Sustain Chem Eng 5:942–947
16. Zheng HY, Zhu YL, Teng BT, Bai ZQ, Zhang CH, Xiang HW,
Li YW (2006) Towards understanding the reaction pathway in
vapour phase hydrogenation of furfural to 2-methylfuran. J Mol
Catal A 246:18–23
35. He J, Yang S, Riisager A (2018) Magnetic nickel ferrite nanoparti-
cles as highly durable catalyst for catalytic transfer hydrogenation
of bio-based aldehydes. Catal Sci Technol 8:790–797
36. Li J, Liu JL, Zhou HJ, Fu Y (2016) Catalytic transfer hydrogena-
tion of furfural to furfuryl alcohol over nitrogen-doped carbon-
supported iron catalysts. ChemSusChem 9:1339–1347
37. Audemar M, Ciotonea C, Vigier KDO, Royer S, Ungureanu A,
Dragoi B, Dumitriu E, Jérôme F (2015) Selective hydrogena-
tion of furfural to furfuryl alcohol in the presence of a recyclable
cobalt/SBA-15 catalyst. ChemSusChem 8:1885–1891
38. Jia P, Lan XC, Li XD, Wang TF (2018) Highly active and selective
NiFe/SiO2 bimetallic catalyst with optimized solvent efect for the
liquid-phase hydrogenation of furfural to furfuryl alcohol. ACS
Sustain Chem Eng 6:13287–13295
17. Reddy BM, Reddy GK, Rao KN, Khan A, Ganesh I (2007)
Silica supported transition metal-based bimetallic catalysts for
vapour phase selective hydrogenation of furfuraldehyde. J Mol
Catal A 265:276–282
18. Chen XF, Zhang LG, Zhang B, Guo XC, Mu XD (2016) Highly
selective hydrogenation of furfural to furfuryl alcohol over
Pt nanoparticles supported on g-C3N4 nanosheets catalysts in
water. Sci Rep 6:28558
19. Bui L, Luo H, Gunther WR, Román-Leshkov Y (2013) Domino
reaction catalyzed by zeolites with Brønsted and Lewis acid
sites for the production of γ-valerolactone from furfural. Angew
Chem Int Ed 52:8022–8025
39. Song JL, Zhou BW, Zhou HC, Wu LQ, Meng QL, Liu ZM, Han
BX (2015) Porous zirconium-phytic acid hybrid: a highly efcient
catalyst for Meerwein-Ponndorf-Verley reductions. Angew Chem
Int Ed 54:9399–9403
20. Jiménez-Gómez CP, Cecilia JA, Durán-Martín D, Moreno-
Tost R, Santamaría-González J, Mérida-Robles J, Mariscal R,
Maireles-Torres P (2016) Gas-phase hydrogenation of furfural
to furfuryl alcohol over Cu/ZnO catalysts. J Catal 336:107–115
21. Corma A, Iborra S, Velty A (2007) Chemical routes for
the transformation of biomass into chemicals. Chem Rev
107:2411–2502
40. Li H, He J, Riisager A, Saravanamurugan S, Song BA, Yang S
(2016) Acid-base bifunctional zirconium N–alkyltriphosphate
nanohybrid for hydrogen transfer of biomass-derived carboxides.
ACS Catal 6:7722–7727
22. Nagaraja BM, Padmasri AH, Raju BD, Rama Rao KS (2007)
Vapor phase selective hydrogenation of furfural to furfuryl
alcohol over Cu-MgO coprecipitated catalysts. J Mol Catal A
265:90–97
41. Li H, Li Y, Fang Z, Smith RL (2019) Efcient catalytic trans-
fer hydrogenation of biomass-based furfural to furfuryl alcohol
with recyclable Hf-phenylphosphonate nanohybrids. Catal Today
319:84–92
23. Tamura M, Tokonami K, Nakagawa Y, Tomishige K (2013) Rapid
synthesis of unsaturated alcohols under mild conditions by highly
selective hydrogenation. Chem Commun 49:7034–7036
24. Merlo AB, Vetere V, Ruggera JF, Casella ML (2009) Bimetallic
PtSn catalyst for the selective hydrogenation of furfural to furfuryl
alcohol in liquid-phase. Catal Commun 10:1665–1669
25. Yuan QQ, Zhang DM, Haandel LV, Ye FY, Xue T, Hensen EJM,
Guan YJ (2015) Selective liquid phase hydrogenation of furfural
to furfuryl alcohol by Ru/Zr-MOFs. J Mol Catal A 406:58–64
26. Fulajtárova K, Soták T, Hronec M, Vávra I, Dobročka E, Omas-
tová M (2015) Aqueous phase hydrogenation of furfural to furfu-
ryl alcohol over Pd-Cu catalysts. Appl Catal A 502:78–85
27. Pang SH, Medlin JW (2011) Adsorption and reaction of furfural
and furfuryl alcohol on Pd (111): unique reaction pathways for
multifunctional reagents. ACS Catal 1:1272–1283
42. Li H, Liu XF, Yang TT, Zhao WF, Saravanamurugan S, Yang
S (2017) Porous zirconium-furandicarboxylate microspheres
for efcient redox conversion of biofuranics. ChemSusChem
10:1761–1770
43. Kuwahara Y, Kango H, Yamashita H (2017) Catalytic transfer
hydrogenation of biomass-derived levulinic acid and its esters to
γ–valerolactone over sulfonic acid-functionalized UiO-66. ACS
Sustain Chem Eng 5:1141–1152
44. Valekar AH, Cho KH, Chitale SK, Hong DY, Cha GY, Lee UH,
Hwang DW, Serre C, Chang JS, Hwang YK (2016) Catalytic
transfer hydrogenation of ethyl levulinate to γ-valerolactone
over zirconium-based metal-organic frameworks. Green Chem
18:4542–4552
45. Song JL, Wu LQ, Zhou BW, Zhou HC, Fan HL, Yang YY, Meng
QL, Han BX (2015) A new porous Zr-containing catalyst with
a phenate group: an efcient catalyst for the catalytic transfer
hydrogenation of ethyl levulinate to γ-valerolactone. Green Chem
17:1626–1632
28. Gilkey MJ, Xu BJ (2016) Heterogeneous catalytic transfer hydro-
genation as an efective pathway in biomass upgrading. ACS Catal
6:1420–1436
1 3

Porous Zr–Thiophenedicarboxylate Hybrid for Catalytic Transfer Hydrogenation of Bio-Based…
46. Li H, Yang TT, Fang Z (2018) Biomass-derived mesoporous Hf-
containing hybrid for efcient Meerwein-Ponndorf-Verley reduc-
tion at low temperatures. Appl Catal B 227:79–89
with high activity for hydrogenation of furfural to furfuryl alcohol.
Catal Lett 147:318–327
54. Srivastava S, Solanki N, Mohanty P, Shah KA, Parikh JK, Dalai
AK (2015) Optimization and kinetic studies on hydrogenation
of furfural to furfuryl alcohol over SBA-15 supported bimetallic
copper-cobalt catalyst. Catal Lett 145:816–823
47. Bon V, Senkovska I, Baburin IA, Kaskel S (2013) Zr- and Hf-
based metal-organic frameworks: tracking down the polymor-
phism. Cryst Growth Des 13:1231–1237
48. Drache F, Bon V, Senkovska I, Marschelke C, Synytska A, Kaskel
S (2016) Postsynthetic inner-surface functionalization of the
highly stable zirconium-based metal-organic framework DUT-
67. Inorg Chem 55:7206–7213
55. Sha YF, Xiao ZH, Zhou HC, Yang KL, Song YM, Li N, He RX,
Zhi KD, Liu QS (2017) Direct use of humic acid mixtures to
construct efcient Zr-containing catalysts for Meerwein-Ponndorf-
Verley reactions. Green Chem 19:4829–4837
49. Verpoort F, Haemers T, Roose P, Maes JP (1999) Characterization
of a surface coating formed from carboxylic acid-based coolants.
Appl Spectrosc 53:1528–1534
56. Natsir TA, Hara T, Ichikuni N, Shimazu S (2018) Highly selective
transfer hydrogenation of carbonyl compounds using La2O3. Bull
Chem Soc Jpn 91:1561–1569
50. Lausund KB, Nilsen O (2016) All-gas-phase synthesis of UiO-66
through modulated atomic layer deposition. Nat Commun 7:13578
51. Xue ZM, Jiang JY, Li GF, Zhao WC, Wang JF, Mu TC (2016)
Zirconium-cyanuric acid coordination polymer: highly efcient
catalyst for conversion of levulinic acid to γ-valerolactone. Catal
Sci Technol 6:5374–5379
57. He J, Schill L, Yang S, Riisager A (2018) Catalytic transfer hydro-
genation of bio-based furfural with NiO nanoparticles. ACS Sus-
tain Chem Eng 6:17220–17229
58. Puthiaraj P, Kim K, Ahn W (2019) Catalytic transfer hydrogena-
tion of bio-based furfural by palladium supported on nitrogen-
doped porous carbon. Catal Today 324:49–58
52. Xie YD, Li F, Wang JJ, Wang RY, Wang HJ, Liu X, Xia YM
(2017) Catalytic transfer hydrogenation of ethyl levulinate to
γ-valerolactone over a novel porous zirconium trimetaphosphate.
Mol Catal 442:107–114
Publisher’s Note Springer Nature remains neutral with regard to
jurisdictional claims in published maps and institutional afliations.
53. Ghashghaee M, Sadjadi S, Shirvani S, Farzaneh V (2017) A novel
consecutive approach for the preparation of Cu-MgO catalysts
Afliations
Tao Wang1 · Aiyun Hu1 · Guangzhi Xu1 · Chen Liu1 · Haijun Wang1 · Yongmei Xia2
2
* Haijun Wang
State Key Laboratory of Food Science & Technology,
Jiangnan University, Wuxi 214122, China
wanghj329@outlook.com
1
Key Laboratory of Synthetic and Biological Colloids,
Ministry of Education, School of Chemical and Material
Engineering, Jiangnan University, Wuxi 214122, China
1 3