Valeric Biofuel Production from γ-Valerolactone over Bifunctional Catalysts with Moderate Noble-Metal Loading

Article abstract of DOI:10.1002/cplu.202100249

SiO₂-Al₂O₃-supported Ru, Ir and Pt-based catalysts with moderate metal loading (1 %) were tested for the first time in the production of pentyl valerate (PV) in liquid phase from γ-valerolactone, pentanol (in excess) and H₂. The acidity of these bifunctional catalysts, plays a key role in the one-pot process comprising two consecutive acid-catalyzed reactions and a metal-catalyzed one. Metal dispersion also shown to be relevant for the conversion of the pentyl pentenoate intermediate into PV by hydrogenation over the metal sites. Pt/SA catalyst with the highest surface acidity and metal dispersion reached optimal GVL conversion with a PV yield of 90.0 % after 10 h, exhibiting a PV productivity of 300 mmol/g_M.h, i. e. a value between three and four times higher than the best result reported until now (91.8 mmol/g_M.h). These findings highlight the potential that noble metal-based catalyst with moderate metal loading have in the valorization of biomass-derived platform molecules such as γ-valerolactone.

Full text of DOI:10.1002/cplu.202100249

A Multidisciplinary Journal Centering on Chemistry
Accepted Article
Title: Valeric Biofuel Production from γ-Valerolactone over Bifunctional
Catalysts with Moderate Noble-Metal Loading
Authors: Karla G. Martínez Figueredo, Emanuel M. Virgilio, Darío J.
Segobia, and Nicolás Maximiliano Bertero
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To be cited as: ChemPlusChem 10.1002/cplu.202100249
Link to VoR: https://doi.org/10.1002/cplu.202100249
01/2020

10.1002/cplu.202100249
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Valeric Biofuel Production from -Valerolactone over Bifunctional
Catalysts with Moderate Noble-Metal Loading
BSc. Karla G. Martínez Figueredo [a], B.Ch.E. Emanuel M. Virgilio [a], Dr. Darío J. Segobia [a] and Dr.
Nicolás M. Bertero *[a]
[a]
Grupo de Investigaciones en Ciencia e Ingeniería Catalíticas (GICIC)
Instituto de Investigaciones en Catálisis y Petroquímica (INCAPE)-CONICET-UNL
Ruta Nac. 168 KM 0, Paraje El Pozo, Santa Fe (3000), Argentina.
E-mail: nbertero@fiq.unl.edu.ar
Supporting information for this article is given via a link at the end of the document.
catalyst surface into pentanoic acid [4]. Then, along ROUTE 1, Yan
et al. reported PV production in combination with pentanol and
pentane (regarded as a biofuel mixture) from GVL without using
pentanol as reagent over Pd(5%)/HY [6]. Although this work
showed certain novelty, severe reaction conditions and a very
high Pd-content were used to reach 60% yield of PV after 30 h.
Abstract: SiO2-Al2O3-supported Ru, Ir and Pt-based catalysts with
moderate metal loading (1%) were tested for the first time in the
production of pentyl valerate (PV) in liquid phase from -valerolactone,
pentanol (in excess) and H2. The acidity of these bifunctional catalysts,
plays a key role in the one-pot process comprising two consecutive
acid-catalyzed reactions and a metal-catalyzed one. Metal dispersion
also shown to be relevant for the conversion of the pentyl pentenoate
intermediate into PV by hydrogenation over the metal sites. Pt/SA
catalyst with the highest surface acidity and metal dispersion reached
total GVL conversion with a PV yield of 90.0% after 10 h, exhibiting a
PV productivity of 300 mmol/gM.h, i.e. a value between three and four
times higher than the best result reported until now. These findings
highlight the potential that noble metal-based catalyst with moderate
metal loading have in the valorization of biomass-derived platform
molecules such as -valerolactone.
A significant fraction of the worldwide energy demand comes from
the transportation sector. In 2018, 28% of the whole energy
[1]
produced in U.S. was used for transportation purposes
.
However, 92% of this energy was supplied by fossil fuels and this
is causing a serious global warming. Lignocellulosic biomass has
been targeted as a promising raw material for the production of
biofuels because: 1) is a kind of non-food-derived biomass; 2) is
an abundant and inexpensive form of biomass; 3) it offers the
energy of 30-160 billion barrels of oil equivalent (bboe) per year
worldwide [2]. The well-known strategy for the production of
biofuels from biomass comprises: (a) deconstruction of
lignocellulose into platform molecules such as levulinic acid (LA)
and -valerolactone (GVL); (b) transformation of these platform
chemicals into biofuels [3]
.
Figure 1. Reaction network, showing the two possible routes, for the one-pot
production of pentyl valerate (PV) from biomass-derived γ-valerolactone (GVL)
over bifunctional metal/acid catalysts [ acid sites;  metal sites].
Valeric esters have been regarded as attractive biofuels due to
their considerably energy density, good volatility-ignition
properties and appropriate polarity in comparison with current
biofuels such as ethanol. Even more, depending on the alkyl
group (ethyl or pentyl), these esters are perfectly compatible for
gasoline or diesel pools, respectively, passing satisfactorily a
250,000 km road trial in 2010 [4]. Particularly, pentyl valerate (PV)
has a higher volatility and better cold-flow properties and lubricity
than fatty acid methyl esters (FAME), i.e. biodiesel. Besides,
engine efficiency and emissions are not significantly affected
when diesel is blended with PV up to 20% [5]. In a pioneering work,
Lange et al. reported 20-50% selectivity to PV from GVL at 548-
573 K and 10 bar of H2 over Pt or Pd/TiO2 catalysts through the
hydrogenation/hydrogenolysis of GVL to pentanoic acid (PA) and
subsequent esterification of PA with pentanol (PL) (ROUTE 1 of
Figure 1) [4]. In this route, the ring-opening of GVL forms initially
pentenoic acid, a very reactive key intermediate that, in the
presence of metal sites and H2, is rapidly hydrogenated over the
On the other hand, a novel route for PV production was proposed
by Chan-Thaw et al. involving the reaction of GVL, PL and H2 over
Cu-based catalysts [7]. In this alternative reaction path (ROUTE 2
of Figure 1), the one-pot process begins with the acid-catalyzed
nucleophilic addition of PL to the carboxylic group of GVL and
ring-opening giving 4-hydroxy pentyl valerate (HPV). Then, the
acid-catalyzed dehydration of HPV leads to pentyl 2-pentenoate
(PP), which can be hydrogenated over metallic sites to PV [7]
.
However, depending on the catalyst and reaction conditions, HPV
can also react with other PL molecule to form 4-pentoxy pentyl
valerate (PPV) and GVL can be converted initially into 2-methyl
tetrahydrofurane (MTHF) by hydrogenation/hydrogenolysis.
To the best of our knowledge, the production of PV through
[7-10]
ROUTE 2 has only been studied over Cu
and Ni-based
1
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10.1002/cplu.202100249
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catalysts [11], whereas bifunctional catalysts based on noble metal
have not been tested yet. The aim of this work was to explore the
potential of SiO2-Al2O3-supported Ru, Ir and Pt-based catalysts
with moderate metal loadings (1%) to carry out this one-pot
catalytic process along ROUTE 2. The main motivation of this
work relies on the necessity of boosting the PV productivity in
these batch one-pot processes, improving the process integration,
before moving to continuous processes for a large-scale PV
(a)

Pt/SA


Ir/SA
production [12]
.
Ru/SA
Specific details regarding preparation, characterization and
catalytic tests are given in Supporting Information SI.1-3. The
characterization results of the bifunctional samples are presented
in Table 1. The metal loading, determined by XRF, was between
0.94% and 1%. Regarding the chlorine content of M/SA samples,
important differences were detected by XRF, following the
pattern: Ru/SA >> Ir/SA > Pt/SA. The pattern for the specific
surface area (Sg) of the samples and the support was: SA > Pt/SA
> Ir/SA > Ru/SA, whereas the pattern for the pore volume was:
SA > Pt/SA  Ir/SA > Ru/SA, indicating a partial blockage of the
pore structure of SA after impregnation with the metal precursors.
The X-Ray diffractograms of calcined samples are shown in
Figure 2.a. For calcined Ru/SA, Ir/SA and Pt/SA samples, only
the diffraction signals of RuO2 (PDF-731469), IrO2 (PDF- 431019)
and PtO2 (PDF-431045), respectively were observed (more
details in section SI.4) with crystalline domains smaller than 4 nm,
10 20 30 40 50 60 70 80
2.
513 K
Pt/SA
503 K
683 K
Ir/SA
463 K
(b)
10
in agreement with other authors [13-15]
.
Table 1. Characterization results.
Ru/SA
Metal
load[a]
(wt%)
Cl
[c]
[d]
Sg[b]
VP
dM
nA TPD[e]
Solid
content[a]
(wt%)
L/(L+B)[f]
(m2/g) (cm3/g) (nm) (mol/m2)
300
500
700
900
1100
Temperature (K)
SA
-
-
460
409
413
425
0.74
0.57
0.62
0.63
-
0.59
0.52
0.65
0.86
0.78
0.65
0.71
0.73
Ru/SA
Ir/SA
Pt/SA
0.98
1.00
0.94
0.737
0.059
0.002
7.4
6.7
2.8
-2
(c)
10
Pt/SA
863 K
Ir/SA
Values determined by: [a] EDXRF; [b-c] N2 physisorption; [d] TEM; [e] TPD of
NH3; [f] FTIR of adsorbed pyridine.
Ru/SA
SA
The TPR profiles of the calcined samples are presented in Figure
2.b. For Ru/SA a sharp reduction peak appeared between 403-
513 K with the maximum at 463 K attributed to RuO2, detected by
XRD [13]. In the case of Ir/SA, the consumption of H2 took place
mainly between 423-583 K with a maximum at 503 K, and
between 623-733 K with a maximum at 683 K, suggesting a
higher heterogeneity of the IrO2 oxide than in the case of Ru/SA
[14]. Finally, in Pt/SA a single and broad reduction peak appeared
between 433-633 K showing its maximum at about 513 K related
to reduction of PtOx species showing different interactions with
the SA support, in agreement with other authors over Pt/SA
533 K
703 K
400
600
800
1000
Temperature (K)
catalysts, prepared from PtClO6 and with a similar Pt loading [15]
.
The metal dispersion (DM) of Ir/SA and Pt/SA samples was
estimated by CO chemisorption at room temperature. DM values
were calculated assuming a stoichiometry (CO):M0SUP=1 [13]. DM
values of about 12.6 and 27.4% were obtained for Ir/SA and Pt/SA,
respectively. Assuming a cubic metal particle model, the average
metal particle size for Ir/SA and Pt/SA was 8.4 nm and 4.1 nm,
respectively. However, for Ru-based catalysts CO chemisorption
is not a suitable technique for determining metal dispersion at the
light of the possible linear and bridged CO adsorption [16]. Besides,
it has been well documented that residual chloride coming from
RuCl3 precursor blocks the CO and H2 adsorption, leading to an
underestimated metal dispersion using chemisorption techniques
Figure 2. Catalyst characterization: (a) XRD pattern of calcined samples [()
RuO2; () IrO2; () PtO2]; (b) TPR profiles of calcined samples; (c) TPD of NH3
profiles from activated samples and SA; (d) TEM images of activated samples.
[17]
.
2
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Additionally, TEM results (Figure 2.d) showed the presence of
metal nanoparticles for the three supported catalysts, in the
ranges 1-13, 2-14 and 1-5 nm for Ru/SA, Ir/SA and Pt/SA,
respectively (Fig. SI.4 of Supporting Information). The pattern for
the average size of metal particles was: Ru/SA (7.4 nm)  Ir/SA
(6.7 nm) > Pt/SA (2.8 nm) (Table 1).
conversion of HPV and PP was higher than over Ru/SA and Ir/SA,
showing HPV<3.1% and PP<3.0% during the run (Figure SI.7.d).
The PV rate formation was appreciable higher over Pt/SA than
over Ru/SA and Ir/SA catalysts, reaching a final value of


PV=51.0% after 8 h with a selectivity of 73.5%, keeping the
PPV<10%. Besides, the C balance was 94.7%, suggesting that
the surface concentration of adsorbed GVL/intermediates is lower
than for Ru/SA.
Acid site density and relative acid strength of reduced samples
and SA support were probed by TPD of NH3. Results are shown
in Figure 2.c and are summarized in Table 1. The evolved NH3
from SA support was evidenced by a broad band between 393 K
and 1073 K, with its maximum at 520 K and a shoulder at 703 K,
indicating the presence of surface sites of different acid strength.
For the three bifunctional catalysts, a broad distribution of acid
strength was also observed, comprising a main band with its
maximum at about 533 K and a shoulder at about 863 K. The
surface acid site density (nA) followed the pattern: Pt/SA > Ir/SA >
SA > Ru/SA (Table 1). This is in agreement with the findings of
other authors, reporting a higher nA value over Ir/SA and Pt/SA
compared to the SA support when the chlorine content is relatively
low [14,18]. In contrast, over Ru/SA the considerable chlorine
content could block not only metal sites, but also support acid
sites, modifying the L/(L+B) ratio and also the strength of the
minority Brönsted acid sites [17,19]. The nature of surface acid sites
Figure 3. Catalytic performance of () Ru/SA; () Ir/SA and () Pt/SA [T=523
K, p=10 bar H2, WC=0.25 g, VPL=40 mL, C0GVL= 0.37 M, stirring rate= 650 rpm,
time= 8 h].
over the samples was determined by FTIR of chemisorbed
[11]
pyridine
and the spectra are presented in Fig. SI.5 of
Supplementary Information. The pattern for the L/(L+B) ratio
(Table 1) followed: SA > Pt/SA  Ir/SA > Ru/SA, showing the
Ru/SA sample a value 17% lower than SA support, indicating that
the higher the chlorine content, the lower the L/(L+B) ratio.
From the characterization and catalytic tests results it is clear that
the three catalysts do not have significantly different textural
properties (differences of about 3.9% in Sg and 10.5% for VP
between Ru/SA and Pt/SA) and all of them are mesoporous
materials as well, where a shape selectivity phenomenon cannot
take place. Thus, differences in activity and selectivity to PV must
be ascribed to the acid/metal site balance at the catalyst surface,
where the chlorine residues can also play a role. The XGVL over
Ru/SA and Ir/SA after 8 h (60.6% and 57.7% shown in Figure 3)
was not significantly higher than the value obtained over SA
support in the absence of metal and H2 (55.5%). This strongly
suggests that the final reaction of the one-pot system, the
hydrogenation of PP into PV, is not so efficiently promoted over
Ru/SA and Ir/SA. Based on the values of the ratio between the
initial GVL moles and the amount of acid sites n°GVL/(nA.Sg.Wc)=
294, 233 and 171 for Ru, Ir and Pt, respectively, it is possible to
infer that the catalyst surface works at a very high coverage in
these samples. The final PPV at 8 h was between 10 and 14.3%
for the three M/SA and SA support, indicating that the undesirable
acid-catalyzed reaction HPV + PL  PPV + H2O is not strongly
affected by the acid site density and metal dispersion. In contrast,
(PP+PV) values at 8 h were equal to 20.5, 26.2, 36.8 and 54.0%
for SA, Ru/SA, Ir/SA and Pt/SA, respectively. This is showing that
the tandem involving the dehydration of HPV into PP and the
subsequently PP hydrogenation into PV was promoted following
the pattern: Pt/SA > Ir/SA > Ru/SA > SA. Taking into account the
metal particle size and the chlorine content of bifunctional
samples (Table 1), it is expected that the dissociative H2
chemisorption would follow the pattern: Pt/SA > Ir/SA > Ru/SA. A
possible and reasonable explanation of the appreciably better
catalytic performance of Pt/SA can be found considering not only
that each acid site must convert a significantly lower amount of
GVL molecules on Pt/SA than on Ru/SA and Ir/SA, but also the
fact that Pt/SA catalyst has smaller metal particles that promotes
more efficiently the H2 chemisorption and PP hydrogenation.
Besides, the chlorine residues, as shown by FTIR in Fig. SI.6,
modify the density and nature of surface acid sites (Table 1),
leading to a lower C balance and a higher TOF over Ru/SA than
over Ir/SA and Pt/SA (Figure 3), suggesting a stronger GVL
adsorption that diminishes PV productivity. Particularly, this new
kind of acid sites are created by the action of residual chlorine on
the -OH groups of SA, as FTIR results showed. Furthermore, a
modification of the H2 chemisorption capacity of the metal
The M/SA samples and the SA support were tested in the one-pot
conversion of GVL into PV, performing previously a “blank”
experiment (section SI.5). When GVL was contacted with PL for
8 h in the presence of SA, at 10 bar of H2 and 523 K, a GVL
conversion of 55.5%, with a PP and PPV yield of 20.5% and
12.2%, respectively (Fig. SI.7.a). However, after 8 h the carbon
balance only reached 77.0%, suggesting the presence of a
relatively high concentration of intermediates adsorbed on SA
support [11]. The catalytic results of the one-pot production of PV
from GVL, PL and H2 through ROUTE 2 over the three bifunctional
catalysts are shown in Figure SI.7 of Supporting Information and
summarized in Figure 3. Due to the fact that the first two reactions
of the one-pot scheme are acid-catalyzed reactions, the TOF
values (Figure 3) were estimated with nA values (Table 1) and the
pattern was Ru/SA (159.6 h-1) > Ir/SA (130.6 h-1)  Pt/SA (124.1
h-1). Ru/SA showed a relatively high initial GVL conversion,
reaching XGVL=60.6% after 8 h. The yield of the intermediate HPV
was lower than 5%, whereas the PP intermediate showed an
increasing yield that reached a value of PP=10.2% (Figure SI.7.b).
The conversion of HPV into PP and consecutive PV (PV=16.0%)
was slightly faster than the undesirable conversion of HPV into
PPV (PPV=11.2%). However, after 8 h the final PV selectivity was
only 26.4% and the C balance reached 78.4%, suggesting that
GVL and/or intermediates remain adsorbed on the catalyst
surface. In the case of Ir/SA catalyst, the GVL conversion after 8
h was 57.7%, i.e. a value slightly lower than with Ru/SA. The HPV
was also lower than 5% during the run due to fast conversion into
PP. However, the rate of PP conversion into PV over Ir/SA was
lower than over Ru/SA, observing a PP=24.9% after 8 h (Figure
SI.7.c). The HPV conversion into PPV was slightly faster than
over Ru/SA (PPV=14.3%). This fact, combined with a lower
hydrogenation activity of PP into PV (PV=11.9%), led to a discrete
final PV selectivity of 20.6%. However, over Ir/SA the C balance
reached 95.0%, a value considerable higher than over Ru/SA.
Finally, Pt/SA showed an initial GVL conversion rate similar to that
of Ru, but reaching a final conversion of 69.4% after 8 h, i.e. the
highest value of the series of catalysts tested. The rate of
3
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10.1002/cplu.202100249
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particles by electronic effects due to this new acid sites and the
after 10 h, a value between three and four times higher than
previously reported values (Table 2). The highest value of PV
productivity reported until now obtained in this work shows clearly
the potential that Pt/SA catalysts with low-moderate Pt loadings
have in the transformation of biomass-derived GVL into valuable
biofuels. Not only the acid/metal balance, but also the
Lewis/Brönsted nature of acid sites play a key role for boosting
the PV productivity. Future approaches focused on the precise
tuning of nA (but with mainly Lewis nature) and DM values appear
to be a suitable road to success for designing continuous
processes for a larger biofuel production.
residual chlorine cannot be discarded, deserving
a future
investigation [19]
.
In summary, Pt/SA with the highest acidity and metal dispersion
of the series was the best catalyst for the PV production from GVL,
PL and H2. Additional experiments varying temperature, H2
pressure, initial concentration of GVL and catalyst/GVL ratio were
carried out over this sample in order to improve GVL conversion
and PV yield. Figure 4 shows the best catalytic performance
obtained over Pt/SA after 10 h and using 0.5 g of catalyst, keeping
constant the rest of the reported experimental conditions. In this
catalytic run, a final GVL conversion of 100% and a PV yield and
selectivity of 90.0% after 10 h were obtained (Figure 4).
Acknowledgements
The authors thank CONICET (Grant PIP 767-2015) and ANPCyT
(Grant PICT-2015-3545) from Argentina for financial support.
Keywords: batch processes • bifunctional catalysts •
heterogeneous catalysis • noble metals • valeric biofuels
[1]
B.A. Babb, M.K. Pruett, U.S. Energy Information Administration, Monthly
Energy Review 2019, April.
[2]
[3]
G.W. Huber, B.E. Dale, Sci. Am. 2009, 301, 52-59.
(a) S.N. Derle, P.A. Parikh, Biomass Convers. Biorefinery 2014, 4, 293-
299; (b) Z. Yi, D. Hu, H. Xu, Z. Wu, M. Zhang, K. Yan, Fuel 2020, 59,
116208; (c) Z. Yu, X. Lu, J. Xiong, N. Ji, ChemSusChem 2019,
10.1002/cssc.201901522.
Figure 4. (a) Evolution with time of the reactant and product concentration over
Pt/SA; (b) Catalytic performance of Pt/SA [T=523 K, p=10 bar H2, WC=0.5 g,
VPL=40 mL, C0GVL= 0.37 M, stirring rate= 650 rpm, time= 10 h].
[4]
[5]
[6]
[7]
[8]
[9]
J.P. Lange, R. Price, P.M. Ayoub, J. Louis, L. Petrus, L. Clarke, H.
Gosselink, Angew. Chemie - Int. Ed. 2010, 49, 4479-4483.
F. Contino, P. Dagaut, G. Dayma, F. Halter, F. Foucher, C. Mounaïm-
Rousselle, J. Energy Eng. 2014, 140, 1-7.
Table 2 compares the previously reported catalytic performance,
PV productivity and operative conditions in batch processes with
our results. Although a PV selectivity higher than 90% has already
been reported by other authors, in this work the PV productivity
during the batch process over Pt/SA reached the highest value.
K. Yan, T. Lafleur, X. Wu, J. Chai, G. Wu, X. Xie, Chem. Commun. 2015,
51, 6984-6987.
C.E. Chan-Thaw, M. Marelli, R. Psaro, N. Ravasio, F. Zaccheria, RSC
Adv. 2013, 3, 1302-1306.
N. Scotti, M. Dangate, A. Gervasini, C. Evangelisti, N. Ravasio, F.
Zaccheria, ACS Catal. 2014, 4, 2818-2826.
Table 2. Comparison of catalytic performance in batch processes for the PV
production in liquid phase reported by other authors with this work.
W. Li, Y. Li, G. Fan, L. Yang, F. Li, ACS Sustain. Chem. Eng. 2017, 5,
2282-2291.
[10] S. Liu, G. Fan, L. Yang, F. Li, Appl. Catal. A: Gen. 2017, 543, 180-188.
[11] K.G. Martínez Figueredo, D.J. Segobia, N.M. Bertero, Catal. Commun.,
2020, 144, 106087.
[b]
[d]
[e]
[f]
T[a]
(K)
pH2
t[c]
(h)
XGVL
SPV
PPV
Catalyst
Ref.
(bar)
(%)
%)
(mmol/gM.h)
[6]
[7]
[12] K. Yan, Y. Yang, J. Chai,Y. Lu, Appl. Catal. B: Environm. 2015, 179, 292-
304.
Pd(5%)/HY
533
523
80
10
30
20
99
90
60
83
88.8
47.7
Cu(8%)/SiO2-
ZrO2
[13] L. Chen, Y. Li, X. Zhang, Q. Zhang, T. Wang, L. Ma, Appl. Catal. A Gen.
2014, 478, 117-128.
[8]
[9]
[14] S.A. D’Ippolito, A.D. Ballarini, C.L. Pieck, Energy and Fuels 2017, 31,
5461-5471.
Cu(16%)/SiO2
523
523
10
10
10
10
91
92
52.3
91.8
Cu(10%)/ZrO2-
ZnAl2O4
91.0
99.0
[15] (a) L.S. Carvalho, C.L. Pieck, M.C. Rangel, N.S. Fígoli, C.R. Vera, J.M.
Parera, Appl. Catal. A Gen. 2004, 269, 105-116; (b) M. Vicerich, V.
Benitez, M. Sánchez, C. Especel, F. Epron, C. Pieck, Can. J. Chem. Eng.
2019, 98, 749-756.
[10]
Cu(10%)/ZrO2
503
523
15
10
10
10
85.4
100
98.1
90.0
87.5
Pt(1%)/SiO2-
Al2O3
300.1
This
work
[16] (a) M. Kobayashi, T. Shirasaki, J. Catal. 1973, 28, 289-295; (b) C.
Gutierrez, J.A. Caram, J. Electroanal. Chem. 1991, 305, 289-299; (c) G.
Corro, R. Gomez, React. Kinet. Catal. Lett. 1979, 12, 145-150.
[17] (a) B. Lin, R. Wang, J. Lin, J. Ni, K. Wei, Catal. Lett. 2011, 141, 1557-
1568 (b) T. Narita, H. Miura, K. Sugiyama, T. Matsuda, R.D. Gonzalez,
J. Catal. 1987, 103, 492-495; (b) T. Narita, H. Miura, M. Ohira, H. Hondou,
K. Sugiyama, T. Matsuda, R.D. Gonzalez, Appl. Catal. 1987, 32, 185-
190; (c) P.G.J. Koopman, A.P.G. Kieboom, H. van Bekkum, J. Catal.
1981, 69, 172-179.
[a] Reaction temperature; [b] H2 pressure; [c] reaction time; [d] GVL conversion;
[e] PV selectivity; [f] PV productivity per gram of metal.
As Table 2 shows, the works employing Cu-based catalyst
involving the ROUTE 2 (Figure 1)[7-10] have shown as advantages
an appreciable activity and remarkable selectivity with a relatively
cheap metal but with a catalyst preparation not so simple, except
the work of Liu et al. [9]. On the other hand, in the work of Yan et
al. [6], involving the ROUTE 1, a Pd-based catalyst with high metal
loading (5%) was employed and more severe reaction conditions.
In contrast, in our case, with low-moderate (1%) noble metal
loading a PV productivity of about 300 mmol/gM.h was reached
[18] A. Giroir-Fendler, P. Denton, A. Boreave, H. Praliaud, M. Primet, Top.
Catal. 2001, 16/17, 1-4.
[19] (a) J.B. Peri, J. Phys. Chem. 1966, 70, 3168-3179; (b) N.B. Muddada, U.
Olsbye, T. Fuglerud, S. Vidotto, A. Marsella, S. Bordiga, D. Gianolio, G.
Leofanti, C. Lamberti, J. Cat. 2011, 284, 236-246.
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10.1002/cplu.202100249
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Bifunctional noble metal-based catalysts of Ru, Ir and Pt/SiO2-Al2O3, with moderate metal content, were tested for the first time in the
one-pot production of pentyl valerate (PV) from -valerolactone (GVL), pentanol and H2. Pt(1%)/SiO2-Al2O3 converted 100% of GVL
with a PV selectivity of 90% after only 10 h at 523 K and 10 bar of H2, leading to the highest PV productivity reported until now in a
batch process.
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10.1002/cplu.202100249
ChemPlusChem
COMMUNICATION
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This article is protected by copyright. All rights reserved.