Study of the versatility of CuBTC?IL-derived materials for heterogeneous catalysis

Article abstract of DOI:10.1039/c9ce01157a

The versatility of CuBTC (or HKUST-1) MOF materials to be functionalized to tune their catalytic activity performance was evaluated. The MOFs were functionalized with ionic liquids (ILs) to give rise to catalysts able to adsorb CO₂and react with epoxides to produce carbonates. The materials are active for this reaction and show good conversion rates at 100 °C and 7 bar CO₂, confirming their ability to fix this gas and transform it into valuable products. In addition, the MOF?IL composite material1can be functionalized to give rise to a bimetallic catalyst, taking advantage of the N-heterocyclic carbene present in the imidazolium-based ILs. Therefore, the material was reacted with palladium dichloride, yielding CuBTC?IL-(NHC)Pd (1Pd) which has been tested for homocoupling of alkynes and imination of benzyl alcohol reactions. The recyclability of the catalysts has been studied and hot filtration tests have been made.

Full text of DOI:10.1039/c9ce01157a

View Article Online
View Journal
CrystEngComm
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: E. S. Larrea, R.
Fernández de Luis, A. Fidalgo-Marijuan, E. M. Maya, M. Iglesias and M. Arriortua, CrystEngComm, 2020,
DOI: 10.1039/C9CE01157A.
Volume 20
Number 15
21 April 2018
Pages 2071-2202
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
CrystEngComm
Accepted Manuscripts are published online shortly after acceptance,
rsc.li/crystengcomm
before technical editing, formatting and proof reading. Using this free
service, authors can make their results available to the community, in
citable form, before we publish the edited article. We will replace this
Accepted Manuscript with the edited and formatted Advance Article as
soon as it is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes to the
text and/or graphics, which may alter content. The journal’s standard
Terms & Conditions and the Ethical guidelines still apply. In no event
PAPER
shall the Royal Society of Chemistry be held responsible for any errors
Yuan Zhuang et al.
Structural study on PVA assisted self-assembled 3D
hierarchical iron (hydr)oxides
or omissions in this Accepted Manuscript or any consequences arising
from the use of any information it contains.
rsc.li/crystengcomm

Please do not adjust margins
Page 1 of 10
CrystEngComm
View Article Online
DOI: 10.1039/C9CE01157A
ARTICLE
Study of the versatility of CuBTC@IL derived materials for
heterogeneous catalysis
Received 00th January 20xx,
Accepted 00th January 20xx
c
a,c
d
Edurne S. Larrea,*a,b Roberto Fernández de Luis, Arkaitz Fidalgo-Marijuan,
Eva M. Maya,
Marta Iglesias d and Maria I. Arriortua a,c
DOI: 10.1039/x0xx00000x
The versatility of CuBTC (or HKUST-1) MOF material to be functionalized to tune its catalytic activity performance was
evaluated. The MOF was functionalized with ionic liquids (IL) to give rise to catalysts able to adsorb CO2 and react with
epoxides to give rise to carbonates. The materials are active for this reaction and show good conversion rates at 100 ºC
and 7 bar of CO2, confirming their ability to fix this gas and transform it into valuable products. In addition, the MOF@IL
composite material 1, can be functionalized to give rise to a bimetallic catalyst taking advantage of the N-heterocyclic
carbene present in the imidazolium based ILs. Therefore, the material was reacted with palladium dichloride yielding
CuBTC@IL-(NHC)Pd (1Pd) which has been tested for homocoupling of alkynes and imination of benzyl alcohol reactions.
The recyclability of the catalysts has been studied and hot filtration tests have been made.
organic linkers, post-synthetic cluster modification,
incorporation or attachment of inorganic catalytically active
species, or generation of metal nanoparticles in the interior of
Introduction
The development of new porous multifunctional materials is
one of the most important research areas within Materials
Science and Technology field. The impact of these materials in
the industrial and social ambits is undoubted, since they have
overcome the performance of classic materials in application
fields such as gas storage, separation and water purification,
among others. During the last two decades, the design of new
porous coordination polymers or MOFs (Metal-Organic
Frameworks) has experienced an outstanding increase. MOFs
offer incomparable advantages for numerous applications due
to their ordered structures, high thermal stability, tuneable
chemical functionality, ultra-high porosity and the availability
of thousands of well-known porous structures with different
pore window apertures, surface areas and chemistry, as well
as chemically tuneable points within their pores network.1
Indeed, MOFs can be easily functionalized modifying the
nature of their pores’ surface to enhance their properties
related with the desired applications.2–4 Some of the most
relevant examples of MOFs porous framework modification
strategies are the post or pre synthesis MOF decoration of the
the pore cages of the material. Recently,
a
new
functionalization strategy has been described, consisting of the
insertion of ionic liquids (IL) into the MOFs as active
components encapsulated within the free space of the MOFs
materials; a combination able to modify and improve their
properties due to the host-guest synergetic interactions of the
solid matrix and liquid encapsulated components.5
ILs are salts with a melting point under the water boiling point.
Cations composing these salts are mainly organic, while anions
can be both organic and inorganic. Possible combinations
between cations and anions make the potential number of ILs
huge6 enabling the selection of the cation-anion pair with
specific characteristics to enhance the MOFs properties.
Indeed, the main physical properties of ILs are, among others:
a wide liquid phase temperature range (in some cases
between -50 ºC and 400 ºC), low vapor pressure, negligible
inflammability and high thermal stability. The progress in IL
knowledge has evidenced their great potential for the sorption
of gases such as CO27 or their great ionic conduction capacity.
The insertion of ILs into MOFs has also given rise to a new
generation of materials, with properties due to both the
coordination polymer and the IL.8–10 In 2011, the first
computational studies about CO2 capture into composite
materials MOF@IL have been published.11,12 The results
suggest that MOF@IL membranes could overcome the
polymeric membranes and the SILP membranes (supported
ionic liquid phase) for the separation of CO2/N2. From this
moment, several MOFs functionalized with ILs have been
prepared and showed an increase on the CO2 sorption and
separation capacity from gas mixtures.5,13–16
a. Dpto. Mineralogía y Petrología, Universidad del País Vasco, UPV/EHU, Sarriena
s/n, 48940 Leioa, Spain.
b. Le Studium Research Fellow, Loire Valley Institute for Advanced Studies, Orléans
& Tours, France.
c. BCMaterials (Basque Center for Materials, Applications & Nanostructures),
UPV/EHU Scientific Park, Martina Casiano Building, 3th floor, Sarriena s/n, Leioa.
d. Instituto de Ciencia de Materiales de Madrid-CSIC, Sor Juana Inés de la Cruz 3,
Cantoblanco, 28049, Madrid, Spain.
Electronic Supplementary Information (ESI) available: [DRX patterns, IR spectra,
thermogravimetric curves of 1, 2 and 3; N2 isotherms of 1, 1Pd, 2 and 3, SEM and
TEM micrographs of 1Pd, XPS survey and deconvolution data, IR, DRX of the
recovered catalysts and hot filtration tests profiles]. See DOI: 10.1039/x0xx00000x
Please do not adjust margins

Please do not adjust margins
CrystEngComm
Page 2 of 10
ARTICLE
Journal Name
The combination of ILs supported on porous materials could
mean also a qualitative leap in their use as catalysts to develop
more efficient and sustainable industrial processes.17 ILs have
been widely used as high efficient catalysts for CO2 conversion;
View Article Online
DOI: 10.1039/C9CE01157A
18–21
and MOF@IL systems have been successfully used as
heterogeneous catalysts for reactions on which CO2 is used to
obtain useful products,22,23 another strategy of CO2 capture
and utilization. Incorporating or encapsulating ILs into MOFs
has important advantages, for instance, the increase of the
CO2 sorption capacity of the system, as well as being easier to
separate and reuse due to the heterogeneity of the MOF@IL
catalysts.22
In addition, the introduction of ILs into MOFs allows further
modifications of the composite material, since second metal
species such as palladium can be incorporated into the pores
of the MOF by means of chemical anchoring to IL molecules. 24
In this work, we have studied the functionalization of CuBTC
with various imidazolium based ionic liquids which act, in some
cases, as ligand for palladium(II), yielding a multifunctional
material CuBTC-IL-(NHC)Pd-complex with catalytic activity for
significant reactions in organic chemical industry and
environmental remediation.
Figure 2 Diffraction patterns of CuBTC (Basolite® C300), 1 and 1Pd.
This way, a Pd functionalized MOF, 1Pd, was obtained with a
1% of Pd loading. In the work of Luo et al.24 a similar approach
to immobilize PdCl2 into the same MOF with the aid of an ionic
liquid was studied. In this work, the authors firstly formed the
Pd-NCH complex, and then inserted it into the pores of CuBTC.
On the contrary, in the present work, we have firstly inserted
the IL to obtain a MOF@IL composite, 1, and then in situ
generated the carbene to finally add the Pd.
Results and discussion
Materials preparation and characterization
After the impregnation with the IL and the functionalization
with Pd, the material was characterized firstly by powder X-ray
diffraction, to confirm that the treatments do not induce any
structural change in the MOF. As it can be seen in figures 1 and
S.1, the diffraction patterns of 1, 2, 3 and 1Pd show the
diffraction maxima corresponding to the CuBTC precursor,
maintaining the initial cell parameters and cubic Fm-3m
symmetry, as concluded by the pattern matching analyses.
Nevertheless, an appreciable variation of the intensity of
specific reflections suggests that, after the incorporation to the
MOF, the IL keeps some degree of order, and is not randomly
distributed within the pores of the material.
To confirm this hypothesis, difference envelope density (DED)
analyses have been performed for 1. DED shows extra electron
density regions ascribed to the ionic liquid molecules within
the MOF, concretely located between the four copper paddle
wheels and near the pore windows defining the dodecahedral
pores of the CuBTC framework (Fig. 2). The similarities
between the DED maps of 1 and 1Pd samples indicate that the
chemical anchoring of the Pd atoms to the ionic liquids does
not modify the general location of the ILs within the porous
framework.
With the aim of studying the easy tunnability of MOFs to
prepare composite materials with catalytic activity, CuBTC
MOF was selected to accomplish various functionalizations. In
a first step, three ionic liquids have been incorporated into the
MOF pores. The introduction of ionic liquids is a simple process
consisting on the impregnation of the MOF with a solution of
the ionic liquid.5,25 The amount of ionic liquid that gets into the
pores of the MOF is variable and depends on the
concentration of the solution used for the impregnation and
on the size of its ions.5 The XRD patterns of the MOF@IL
composites show that the MOF structure does not change
because of the insertion of the ionic liquids(Fig. S.1). The IR
spectroscopy (Fig. S.2), thermogravimetric analyses and
surface area calculations of the IL-loaded materials confirm the
incorporation of the IL into the porous framework, as it will be
discussed in the following sections.
Taking advantage of the fact that the imidazolium anion of the
used ILs could form an N-heterocyclic carbene (NHC), 1 has
been functionalized with palladium. First, the in-situ
preparation of the free carbene was carried out by a basic
treatment of 1, and then addition of a Pd salt (Scheme 1).
Bu
Bu
Bu
Cl
Cl
N
N
N
N
N
N
PdCl2
Base
Pd
Scheme 1. In situ formation of CuTC-IL-(NHC)Pd (1Pd).
Figure 1 Difference envelope density maps of 1 (yellow contours) and CuBTC
structure representation (Cu atoms= yellow spheres, O atoms = red spheres,
trimesate linker= light purple sticks) in the (a) [100] and (b) [110]
crystallographic directions.
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 10
CrystEngComm
Please do not adjust margins
Journal Name
ARTICLE
Previously reported theoretical studies11,26,27 concluded that IL
molecules confined into MOFs are packed more ordered than
those in the bulk, with a tendency of the anions to be
accommodated around the metal centers. In addition, it has
been detected a lower mobility of the anion than the cation,
suggesting that the chemical interactions established between
the framework and the anion are stronger than those
established with the cation. Despite the general tendencies
reported by these studies, the DED analyses do not allow
discerning the position of the anion/cation components of the
IL within the MOF. Nevertheless, the color change observed
for 2 after the impregnation of activated CuBTC with chloride
IL, from light blue to light green, suggests that open metal sites
of the copper paddle wheel clusters are occupied by the
cholride of the IL molecules, in good agreement with the
general rules of IL locations within MOFs indicated by
computational studies. This color change is not appreciable for
CuBTC loaded with [BMIM][BF4] and [BMIM][Br], since
tetrafluoroborate and bromide are bigger and less
coordinative than chloride anion.
Thermogravimetric curves of the IL loaded materials show two
extra weight loss stages with the regard to CuBTC: one
occurring approximately between 100 and 300 ˚C ascribed to
the thermal displacement of the anions linked to the copper
cations, and the second one an extra calcination process at
high temperatures (300 – 500 ˚C), partially overlapped with
the trimesate organic ligand calcination (Fig. S.3). The blocking
of copper axial positions by the ILs’ anions is further confirmed
by the decrease of the weight loss associated with the
coordinated water molecules release, before 80 ˚C.
View Article Online
DOI: 10.1039/C9CE01157A
Figure 4 High-resolution Pd 3d XPS spectra of 1Pd.
Once we have confirmed the presence of the IL, we have
quantified the amount by two techniques: thermogravimetric
analysis and elemental analysis. Comparing the TG curves of
CuBTC and 1 (Fig. S.3), there are two additional mass loss
stages, one before and the other one after the ligand
calcination. Taking into account this mass loss we have
determined the amount of [BMIM][BF4] into the CuBTC, 0.4
mol per 1 mol of MOF for 1. This result is in agreement with
chemical data obtained by CHN elemental analysis. The same
procedure was followed for 2 and 3, being the calculated
formulas in table 1. The amount of Pd present in 1Pd was
determined by ICP-AES, being approximately 0.1 mol per 1 mol
of CuBTC.
Finally, the surface areas of all the compounds have been
determined by BET analysis (Table 1) of N2 adsorption
isotherms (Fig. S.4). When inserting the ionic liquid into the
MOF a notable decrease on the surface area is observed.
When 1 is functionalized with palladium to form 1Pd, the
decrease on the surface area is less appreciable but also
important (Fig. S.4). As expected, the ionic liquids are located
at the pores reducing the accessible porosity. With the
addition of palladium, this effect is increased because of the
linkage between the palladium and the imidazolium cation.
Palladium functionalized material 1Pd was also characterized
by electron microscopy and X-ray photoelectron spectroscopy
The material was also characterized by IR spectroscopy to
determine the presence of the IL into the structure. In figures
3 and S.2 the IR spectra of CuBTC and compounds 1, 2, 3 and
1Pd are displayed. The presence of the IL into the pores of the
MOF produced some absorption bands that are not present in
the CuBTC spectrum. There is a group of bands between 3000
and 2850 cm-1 due to alkyl C-H bonds corresponding to the
alkyl substituents of the imidazolium cation. At 1160 and 1030
cm-1 two bands corresponding to the vibration of C-N bonds of
imidazolium cation are observed. Finally, the band due to the
-
B-F bonds corresponding to the BF4 anion present in 1 and
(XPS). SEM micrographs show that the sample has
a
1Pd appears at 1080 cm-1.
homogeneous particle size distribution (Fig. S.5). EDX analyses
show that the particles are composed by copper and
palladium. TEM images reveal that palladium nanoparticles
have been also generated during the Pd incorporation process
in the particle surface (Fig. S.6). These particles have a size of
5-15 nm, much larger than the crystallographic pore diameter
of CuBTC (1.4 nm), so the growth of these Pd-NP must be over
the surface and not inside the pores. Nonetheless, palladium is
present along the whole material and taking into account the
BET surface area decrease observed from 1 to 1Pd, we can say
that the Pd cations have been also incorporated to the
imidazole molecules encapsulated within the MOF material.
XPS analyses (Fig S.7 and table S.1) of 1Pd shows two different
signals for Pd (Fig. 4), one of Pd(0) corresponding to the Pd-
NPs at the surface of the catalyst, and another of Pd(II)
Figure 3 Details of the FT-IR spectra of of CuBTC (Basolite® C300), 1 and 1Pd.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
CrystEngComm
Page 4 of 10
ARTICLE
corresponding to the palladium coordinated to the IL. The
Journal Name
Table 2. Total conversion rates and yield of the reaction forVieepwicAhrltoicrloehOyndlirnine
DOI: 10.1039/C9CE01157A
signal of Pd(II) is a 60 % of the palladium total content at the carbonate (ECHC).
surface.
Catalyst
CuBTC
C (%)[a]
83
90
100
75
ECHC yield (%)
52
75
85
55
Table 1. Formulas and surface area (BET) of compounds 1, 2, 3 and 1Pd.
1
2
3
Formula
Cu3(BTC)2
SA
MV
MA
ESA
CuBTC
1838 0.7563 1488 350
1
2
3
Cu3(BTC)2@0.4[BMIM][BF4]
Cu3(BTC)2@1.2[BMIM][Cl]
Cu3(BTC)2@0.3[BMIM][Br]
Cu3(BTC)2@0.4[BMIM][BF4]·0.1Pd
1058 0.4408
1027 0.6222
851
855
905
627
207
172
59
Reaction conditions: dichloroethane as solvent, 100 ºC, 7 bar of CO2, 10 mol% of
catalyst (based on Cu); [a] 20 h.
964
693
0.5842
0.8334
1Pd
66
The reaction carried out over not functionalized CuBTC in the
same conditions is less selective towards the formation of the
carbonate, being the yield 52%. This result is in good
agreement with the one reported by Macias et al.30, who used
3 mol % of CuBTC (100 ⁰C, 7 bar of CO2) obtaining a ECHC yield
of 33 %. Therefore, the insertion of the ionic liquids enhances
the catalytic activity of this MOF.
After the reaction, the catalyst were recovered, washed and
characterized by powder X-ray diffraction and IR spectroscopy.
The diffraction patterns do not change after the catalytic
reaction as can be seen in figure S.8. In the IR spectra the
bands corresponding to the ionic liquids are observed after the
catalytic reactions (Fig. S.9) and one additional band appears in
the range of 1800-1820 cm-1 due to the cyclic carbonate that
SA: BET surface area (m2/g); MV: Micropore volume (cm3/g); MA: Micropore area
(m2/g); ESA: External surface area (m2/g)
Catalytic activity tests
The insertion of ionic liquids into MOFs changes the surface
and chemical properties of these, giving rise to new
functionalities, such as enhanced catalytic activity. In addition,
the ILs based on imidazolium salts allow introducing another
metal center at the N-carberne position, giving rise to
multifunctional catalysts. Therefore, MOF@IL composites 1, 2
and 3 and palladium functionalized MOF@IL composite 1Pd,
were studied as catalysts.
1. Cycloaddition of CO2 to epoxides. In the cases of 1, 2 and 3, has got retained into the pores of the catalysts.
Recycling Test. Reutilization is one of the greatest advantages
the combination of a porous structure with the ability to
adsorb CO2 of CuBTC, with the good catalytic properties of
ionic liquids in the cycloaddition of CO2 to epoxides,18 could
give rise to suitable heterogeneous catalysts for the addition of
CO2 to epoxides. As model, we have selected the
epichlorohydrin epoxide as subtract (Scheme 2) and results are
shown in Table 2. All materials result effective for the reaction
being 2 the more active and selective as can be expected by
the higher load of IL (entry 2). All the reactions were carried
out in dichloroethane as solvent and 7 bar of CO2, with 10
mol% of catalyst (based on Cu). The conversion after 20 hours
was determined by GC-MS (Table 2).
of heterogeneous catalysts, and can also provide useful
information about the anchoring process and catalyst stability
along the catalytic cycle. Five cycles of reaction were carried
out with catalyst 2 to test its recyclability. The conversion of
the reaction was 100% in all the cycles. In addition, the yield of
the epichlorohydrin carbonate increases from the first cycle to
the third, being 100% in the consecutive cycles (Fig. 5).
2. Alkyne homocoupling. Heterogeneous homocoupling of
alkynes (Scheme 3) offers important advantages as simple
reuse and recovery with respect to the soluble counterparts.
Different palladium−copper cocatalyzed homocoupling of
terminal alkynes have been applied as efficient catalysts
O
O
10% cat
O
(PdCl2/PS-PEG-PPh2
resin
/CuI,
SBA-15@DABCO)-
O
Pd(OAc)2/CuI, Pd/C−CuI, etc.).31 Thus, we have used the
multifunctional CuBTC-IL-Palladium material (1Pd) as catalyst
for C-C coupling reactions.
R
7 bar CO2
100ºC
R
ECHO
ECHC
Scheme 2. Cycloaddition of CO2 to epichlorohydrin (ECHO).
As it can be expected, the best performance is obtained for
catalyst 2. On one hand, this is the catalyst with the highest
amount of ionic liquid inside the pores. This can be explained
by the smaller size of the anion Cl-, which allows a higher
loading of the MOF. On the other hand, it has been previously
observed that the IL anion could play an important role on the
catalytic activity, as it has been reported for ionic liquids and
poly(ionic liquids) containing Cl-, PF6- or BF4.19,28,29 The chloride
anion is more reactive because it is more nucleophilic and
smaller than the other anions.
Figure 5 Recycling of catalyst 2 for the formation of epichlorohydrin carbonate
(ECHC).
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 10
CrystEngComm
Please do not adjust margins
Journal Name
ARTICLE
6 % cat
View Article Online
DOI: 10.1039/C9CE01157A
Toluene
Et3N, 100ºC
Scheme 3. Ethynylbenzene homocoupling reaction.
Toluene has been used as solvent, trimethylamine as base, and
the catalyst proportion was 6 mol% based on Pd in 1Pd, and
the temperature was set at 100 ºC. For ethynylbenzene, a
conversion of 70 % has been obtained at 7 h being 99% after
24 hours (Fig. 6). When using parent CuBTC-IL (1) as catalyst at
the same conditions no conversion is observed. Therefore,
palladium is the catalytic active species in 1Pd.
Figure 7 Conversion rates for the successive cycles of alkyne homocoupling
with catalyst 1Pd.
was about 10% after 24 h, meaning that it was necessary to
add the cocatalyst to obtain reasonable product yields. The
same reaction can be also catalyzed by Pd0, as demonstrated
by Li et al.33 more recently. In this case, Pd nanoparticles were
supported over Al(OH)3 and the use of an oxidant was needed
to obtain good conversions. The highest yield of the diyne was
obtained when using 0.1 mol% of Pd, 1 eq of NaOAc as base
and 30 mol% of Ag2SO4 as oxidant in DMSO. After 16 hours at
90 ºC, the yield was 99%. In absence of the oxidant and at the
same reaction conditions, the yield was of 55 %. Although for
1Pd the dosage of catalyst is higher than in other previously
reported studies, there is no need to add other cocatalyst or
oxidants to obtain good yields.
Figure 6 Kinetic profile for the ethynylbenzene homocoupling with 1Pd.
After the reactions, all the catalysts have been recovered,
washed and characterized by powder X-ray diffraction, IR
spectroscopy, ICP-AES and transmission electron microscopy.
The diffractograms of the recovered catalyst show the same
pattern of the fresh catalyst (Fig. S.10). The chemical analysis
shows that the recovered catalyst has lost a 22% of the initial
Pd content for the reaction with ethynylbenzene.
To study the scope of the reaction, various alkynes have been
used as substrates in the same conditions described for
ethynylbenzene. The conversion has been measured after 24
hours and the results are collected in table 3. Good conversion
rates were obtained with almost all kind of R substituents,
except for the p-aminophenyl. In this case, no conversion is
observed.
Recycling Test. Recycling tests were carried out over 1Pd for
the ethynylbenzene homocoupling. As can be seen in figure 7,
from the first to the second cycle there is a drastic decrease of
the conversion. In the following cycles, however, the
conversion is maintained approximately at 30%.
Hot Filtration. In order to confirm the heterogeneity of the
catalyst, a leaching test has been performed by hot filtration
method. After 1 hour of reaction, when the conversion rate
has reached the 11 %, the catalyst has been removed by
filtration and reaction was maintaned until 48 hours. Aliquots
of the reaction have been analyzed by GC-MS to determine the
conversion at various times (Fig. S.11). Although, just after the
filtration, the reaction seems to be stopped, after 6 hours, the
conversion rate increases again, being the total conversion
after 24 hours 92 %, and, after 48 hours, 98 %. These results
confirm that there is a leakage of the active species from the
solid to the reaction solvents.
Table 3. 1Pd-catalyzed alkyne homocoupling.
R
R
R
Entry
R
CT % (24 h)
99
1
2
3
4
5
6
Ph
4-F
4-OMe
4-NH2
cyclohexyl
C6H13
100
61
traces
99
100
Reaction conditions: 6 mol% cat, Et3N, 100 ºC, Toluene
As mentioned before, in several studies PdII containing
heterogeneous catalysts were used with CuI acting as
cocatalyst. Li et al.32 obtained a yield of 100 % of dyine with a
mesoporous silica SBA-15-supported palladium catalyst,
SBA15@DABCO-Pd, when using 0.23 mol% of Pd, 1 mol% of
The leaching of the active species from the solid catalyst to the
reaction solvent, could explain the activity decrease from the
first to the second cycle when the catalyst is recycled.
However, the fact that in the subsequent cycles the conversion
CuI as cocatalyst,
1
eq of DABCO (1,4-diaza-
bicyclo[2.2.2]octane) as base at room temperature and after 4
h of reaction in acetonitrile. Without CuI the yield of the diyne
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Please do not adjust margins
CrystEngComm
Page 6 of 10
ARTICLE
Journal Name
rates are very similar, suggests that the leaching takes place in
the first stage of the first reaction, and then the catalyst
chemical content is maintained stable along the subsequent
cycles.
View Article Online
DOI: 10.1039/C9CE01157A
3. Imination of benzyl alcohol. Imination proccess from
unreactive alcohols without an oxidant is an important non-
polluting route to provide aldehydes and related products.34,35
The resultant imines are important key intermediates in the
synthesis of nitrogen containing heterocyclic compounds. In
this sense, palladium containing catalysts have shown a good
catalytic activity in this kind of reactions.36–39 Therefore, the
palladium functionalized CuBTC@IL, 1Pd, has been evaluated
for the imination of anilines with benzyl alcohol.
Figure 8 Recycling test for the alkylation of aniline. In blue, yield of product a; in
orange, yield of product b; in green, yield of product c.
solvent. After 24 h the yield of the imine was 51 %. After
screening various ligands and bases they succeeded in
decreasing the amount of Pd and the temperature, obtaining a
yield of 99 % of the imine when using 1 mol% of PdII, 15 mol%
Thus, aniline and benzyl alcohol were used as model reactants
in order to set the most convenient reaction conditions for the
catalyst. The temperature was set at 100 ºC and the catalyst
percentage in 2 mol%, with regard to the palladium content.
After 24 hours, a total conversion of 95 % has been obtained
t
of Et3N, 4 mol% of TEMPO, 20 mol% of BuOK in toluene, at
room temperature and after 3 days. Kwon et al.37, on the other
hand, used Pd nanoparticles entrapped in boehtite nanofibers.
The reaction was carried out in heptane with 2 mol% of Pd, 1
atm of O2. After 20 h at 90 ºC the conversion of 90% was
reached. In the case of 1Pd we have palladium in both
oxidation states, Pd0 as nanoparticles at the surface and PdII
into the MOF channels. Although the reaction conditions used
in this study are not the same as those reported before, the
yield of the iminie obtained is higher than that reached by
Pd(OAc)237 in harder conditions of temperature. Therefore, it is
expected that the Pd-NPs have and important contribution to
catalytic activity of the material.
Recycling Test. The recyclability of the catalyst was studied for
the aniline and benzyl alcohol reaction. Between each cycle,
the catalyst was washed with toluene and dried under vacuum
to remove all the solvent and water molecules from the pores.
As it can be observed in figure 8, the conversion decreased
from one cycle to another gradually, indicating an activity loss
of the catalyst. When decreasing the total conversion, the
yield of the byproducts decreases until zero in the fourth cycle.
When the diffraction pattern of the catalyst recovered after 4
cycles is analyzed, the diffraction pattern of the fresh catalyst
is observed. However, some new peaks are present in the
pattern. The formation of a new compound takes place;
however, it could not be identified by the extra diffraction
peaks. In the FT-IR spectra, there are also some additional
absorption bands at 1550, 1490 and 1272 cm-1. Therefore, the
successive use of the catalyst gives rise to its gradual
decomposition.
with
81%
selectivity
to
the
corresponding
diphenylmethanimine (a) (table 4, entry 1) and N-benzylaniline
(b) and 1,2-diphenyldiazene (c) as side product (Scheme 4).
NH2
+
H
2mol% cat
100 ºC
OH
N
N
N
+
+
N
a
b
c
Scheme 4. Reaction catalyzed by 1Pd between aniline and benzyl alcohol.
The scope of the reaction was studied with different p-
substituted anilines. As can be observed in table 4 the imine
was obtained as main product. Good conversion rate was
observed for the 4-anisidine (entry 3), because of the
activating effect of the methoxy group. After the reactions, the
catalyst was recovered, washed thoroughly and characterized
by powder XRD and ICP-AES. The X-ray diffraction spectra
show no structure alteration of the catalyst (Fig. S.12).
However, the ICP-AES analysis shows that the after the
reaction the recovered catalyst has lost a 45 % of the initial Pd
content.
Table 4. Total conversion rates, conversion and selectivity of each product for
the amine alkylation of various amines.
-R
-H
-Me
-OMe
-Cl
CT (24 h)
95%
20%
88%
36%
Ca (Sa)
Cb (Sb)
9% (9.5%)
Cc (Sc)
9% (9.5%)
0
17% (19 %)
6% (17%)
77% (81%)
20% (100 %)
71% (81%)
30% (83%)
0
0
0
The reaction carried out with 1 in the same conditions yielded
1.5 % of the imination product after 24 hours, confirming that
the catalytic active species in the material is the palladium.
Both Pd0 and PdII can catalyse the imination reaction of benzyl
alcohol. Jiang et al.36 used Pd(OAc)2 as catalyst and they
improved the system by adding TEMPO radical as cocatalyst, a
ligand and a base to develop one-pot and green imine
synthesis. For the reaction with Pd(OAc)2, the reaction
conditions were set as 2 mol% of PdII, 120 ºC and toluene as
Hot Filtration. The hot filtration test clearly shows that there is
leaching of palladium to the reaction medium. The test was
done for the reaction between aniline and benzyl alcohol and
the catalyst was filtered after 30 minutes of reaction, when the
total conversion rate was 9 %. The kinetic profiles of the
reaction with catalyst and that of the hot filtered reaction are
almost the same (Fig. S.13); therefore, the catalysis process is
mainly homogeneous and due to the palladium that leaks from
the material to the reaction medium. The leaching of
6 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 7 of 10
CrystEngComm
Please do not adjust margins
Journal Name
ARTICLE
palladium seems to take place gradually, since the chemical The materials were characterized by powder X-ray diffraction
View Article Online
DOI: 10.1039/C9CE01157A
analysis of the catalyst removed from the reaction medium at (XRD), FT-IR spectroscopy, elemental analysis and inductively
half an hour shows a loss of palladium content of 17%, while coupled plasma atomic emission spectroscopy (ICP-AES). XRD
after 24 hours it is 45%.
data were recorded on a Philips X’Pert diffractometer with
secondary monochromator. Profile pattern matching analyses
were carried out with the X-ray diffraction patterns of the
pristine CuBTC sample, and those loaded with ionic liquids and
palladium. After extracting the structure factors from the final
fittings, difference envelope density maps were constructed
taking into account the structural factors for the {420}, {422},
{200}, {220}, {222} and {440} reflections of the CuBTC structure
and the experimental data obtained after encapsulating the
ionic liquids within the pores. To this end, the procedure
described previously by Yakovenko. et. al. was applied.40
The IR spectra (KBr pellets, 1% wt) were obtained with a Jasco
FTIR 6100 spectrometer in the 400–4000 cm–1 range.
Elemental analyses were performed on an EuroVector Euro EA
Elemental Analyzer (CHNS) and ICP-AES analysis on a Horiba
Yobin Yvon Activa spectrometer.
Thermogravimetric analyses were carried out in order to
determine the ionic liquid loading and the water content of
the MOF under synthetic air atmosphere with a NETZSCH STA
449F3 DSC–TGA instrument. A crucible containing the sample
(ca. 10 mg) was heated at 5 °Cmin–1 in the temperature range
30–80 °C, then an isotherm step of 1 hour at 80 °C was carried
out in order to remove all the water from the compounds and
finally another heating step at 5 °Cmin–1 from 80 – 600 °C was
performed. The gas flow was 60 mL/min for the whole
measure.
Experimental
Materials and methods
All starting materials and solvents were obtained from reliable
commercial sources and used without further purification.
Metal-organic framework CuBTC was purchased from Sigma-
Aldrich as Basolite® C300. Ionic liquids 1-Butyl-3-
methylimidazolium tetrafluoroborate ([BMIM][BF4]) and 1-
Butyl-3-methylimidazolium chloride ([BMIM][Cl]) were
purchased
from
Sigma-Aldrich,
while
1-Butyl-3-
methylimidazolium bromide ([BMIM][Br]) was purchased from
Abcr GmbH. LiN(Si(CH3)3)2, PdCl2, toluene, acetonitrile,
trimethylamine, biphenyl, benzyl alcohol, 1,2-dichloroethane
and all substrates used for catalytic reactions were purchased
from Sigma-Aldrich. Acetone was purchased from Panreac.
Synthesis of CuBTC@IL (1 – 3)
To introduce the ionic liquids [BMIM][BF4], [BMIM][Cl] and
[BMIM][Br] into the MOF pores, an impregnation method
previously described by Sezginel et al. was used5. In a typical
synthesis, 350 mg of CuBTC (Basolite® C300) (approx. 0.5
mmol) were heated at 120 °C for 12 hours under vacuum.
After this time, a solution of 0.7 mmol of the ionic liquid in 15
mL of acetone was added to the dried CuBTC. The suspension
was maintained under stirring at 30 °C for 6 h. Then, the
resulting product was washed with acetone three times to
remove the ionic liquid not adsorbed by the MOF, and air-
drying. CuBTC@0.4[BMIM][BF4] (1): Exp.: H 5(1)%, C 27.8(2)%,
and N 1.53(6)%; Theor.: H 4.51%, C 25.89%, and N 1.14%.
CuBTC@1.2[BMIM][Cl] (2): Exp.: H 6(1)%, C 35.2(1)%, and N
Compound 1Pd was also characterized by scanning electron
microscopy and energy-dispersive X-ray spectroscopy (EDX) in
order to confirm that palladium particles did not remain in the
MOF surface. A JEOL JSM-7000F field emission scanning
electron microscope was used for this purpose. High-
resolution transmission electron microscopy (HRTEM) was
used to characterize the catalyst 1Pd, as-synthesized and after
the catalytic reactions, and Energy Dispersive X-ray
Spectroscopy (EDS) was used to identify the elements in the
samples.
3.79(4)%; Theor.:
CuBTC@1.2[BMIM][Br] (3): Exp.: H 7.7(9)%, C 26.0(8)%, and N
0.80(4)%; Theor.: H 4.3%, C 26.2%, N 0.9%.
H
3.8%,
C
36.8%,
N
3.7%;
The specific surface areas of 1, 2, 3 and 1Pd were determined
by N2 isotherms at 77K using BET analysis. The isotherms of 1,
3 and 1Pd were measured on a Quantachome Autosorb iQ®
instrument, while 2 was measured on a Micromeritics
ASAP2420 multi-port surface area and porosimetry analyzer.
The X-ray photoelectron spectroscopy measurements were
carried out on a SPECS system equipped with a Phoibos 150
1D-DLD analyzer. A survey spectrum was made to determine
the elements present (wide scan: step energy 1 eV dwell time
0.1 s, pass energy 80 eV) and detailed spectra for each
detected element were performed (detail scan: step energy
0.08 eV, dwell time 0.1 s, pass energy 30 eV) with an exit angle
of 90°. The spectrometer were previously calibrated with Ag
(Ag 3d5/2, 368.26 eV). The spectra were fitted by the software
CasaXPS 2.3.16, which model the Gauss-Lorentzian
contributions after a background substraction (Shyrley). The
concentration values were calculated by correcting them with
relative atomic sensitivity factors (Scofield).
Functionalization of CuBTC@0.4[BMIM][BF4] with Palladium (1Pd)
The composite material 1 was dried at 120 °C for 12 hours
under vacuum. Then, 5.5 mg of LiN(Si(CH3)3)2 solved in 2 mL of
toluene were reacted with 50 mg of 1 under stirring at room
temperature in a 5 mL micro-reaction vessel. After 30 minutes,
the solid was decanted and a solution of 5 mg of PdCl2 in
acetonitrile (2 mL) was added to the powder and the mixture
was stirred during 6 hours at 85.5 °C. The product was washed
with hot acetonitrile in order to remove the remaining PdCl2.
Finally, several washings with acetone were made and 1Pd was
air-drying. CuBTC@0.4[BMIM][BF4]·0.1PdCl2·17H2O: Exp.: H
5.7(4)%, C 23.1(4)%, N 0.77(6)%, and Pd 1.1(1)%; Theor.: H
4.55%, C 24.98%, N 1.10% and Pd: 1.04%.
Materials characterization
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 7
Please do not adjust margins

Please do not adjust margins
CrystEngComm
Page 8 of 10
ARTICLE
Journal Name
Catalytic tests
Conclusions
View Article Online
DOI: 10.1039/C9CE01157A
Before the catalytic activity tests, the materials were dried at
140 °C in vacuum for 1 hour to remove the solvent molecules
from the pores that could interfere in the reactions. MOF@IL
composite materials 1, 2, and 3 were used in the cycloaddition
of CO2 to epoxides. The catalytic activity of 1Pd was studied for
two different type of reactions: alkyne homocoupling and
imination of benzyl alcohol.
Metal-organic frameworks are very versatile materials due to
the combination of their porosity and their interesting host-
guest chemistry. Functionalizing CuBTC with ionic liquids new
recyclable materials able to fix and transform CO2 by the
catalytic cycloaddition of CO2 to epoxides has been obtained,
being reused at least 5 times without loss of catalytic activity.
In these new materials, the ionic liquids are located near the
copper clusters, at the window apertures of the dodecahedral
pores of CuBTC structure. Incorporation of IL has an impact on
the thermal properties and water uptake of the host
framework, since the color change of the compounds suggest
that the chloride and bromide anions bind the metal open
positions of the copper paddle wheel units. Imidazole ILs offers
the opportunity to introduce additional functionalization into
the MOF, taking advantage of the N-heterocyclic carbene
nature of the ionic liquid cation. In this sense, palladium has
been anchored to the carbene, obtaining the catalyst 1Pd. This
material has been tested for alkyne homocoupling and
imination reactions. In the case of alkyne homocoupling,
catalyst 1Pd is effective catalyst for both reactions and can be
easily recovered from the reaction media although in these
case some Pd-leaching was observed.
In the cycloaddition reaction, a Pioclave Buchi glass reactor of
10 mL was used. 3.15 mmol of the epichlorohydrin (ECH) and
catalyst (10% mol Cu) and 0.5 mL of dichloroethane were
placed in the reactor. Then, the reactor was filled with CO2,
and, after three purges, the pressure was set at 7 bar. The
reaction mixture was stirred at 100 ºC during 20 hours. The
1
conversion of the reaction was evaluated by H-NMR and GC-
MS.
For the alkyne homocoupling, ethynylbenzene was used as
model substract in order to determine the best reaction
conditions (solvent, temperature, catalyst amount…). In a
typical reaction, 10 mg of catalyst 1Pd were dispersed in 0.5
mL of toluene in a 5 mL micro-reaction vessel. Then, 5.5 μL
(0.05 mmol) of ethynylbenzene and 8.5 μL (0.06 mmol) of
triethylamine were added, being the catalyst (Pd)/substrate
ratio 3%. Biphenyl was also added as internal standard for gas
chromatography-mass spectrometry (GC-MS). The reaction
took place under stirring at 100 °C. Aliquots of the liquid phase
were collected at certain times to be analyzed by GC-MS.
Several substrates, besides ethynylbenzene, were used to
evaluate the scope of the reaction. A blank reaction with 1 was
also carried out in the same conditions as described for 1Pd.
For the imination of benzyl alcohol, aniline was used as model
substrate. In a 5 mL glass micro-reaction vessel, 10 mg of
catalyst 1Pd were dispersed in 0.2 mL of benzyl alcohol. Then,
4.5 μL (0.05 mmol) of aniline and approximately 1 mg of
bifenyl, as internal standard for GC-MS, were added to the
suspension. The reactor was heated at 100 °C under stirring.
Aliquots of the liquid phase were collected at certain times to
be analyzed by GC-MS. Several substrates, besides aniline,
were used to evaluate the scope of the reaction. A blank
reaction with 1 was also carried out in the same conditions as
described for 1Pd.
Hot filtration test were carried out for both reactions with the
model substrates. After a certain time of reaction the solution
was filtered and the liquid without solid catalyst was let
reacting. Aliquots were taken at certain times to analyze them
by GC-MS.
In order to evaluate the reusability of the catalyst, successive
cycles were made. After each cycle, the catalyst was recovered
by centrifugation, washed with toluene three times, and dried
at 140 °C. Then, the reactor was charged again with the
recovered catalyst and fresh reactants. This process was
repeated four times.
Conflicts of interest
There are no conflicts to declare.
Acknowledgements
Financial support from the Spanish Ministry of Economy and
Competitiveness (MINECO) through projects MAT2016-76739-
R
and MAT2017-82288-C2-2-P (AEI/FEDER, EU), Basque
Government Economic Development and Infrastructure
Department under the ELKARTEK program LION KK-
2018/00102 project, and GIU18/197 UPV/EHU research group
funding is acknowledged. The European Commission Research
&
Innovation H2020-MSCA-RISE-2017 (Ref.: 778412)
INDESMOF project is also acknowledged. The authors thank
the technicians of SGIker (UPV/EHU) for the technical support
and to Dr. Garikoitz Beobide for the N2 isotherms.
References
1
H. Furukawa, K. E. Cordova, M. O’Keeffe and O. M. Yaghi,
Science, 2013, 341, 1230444.
A. K. Cheetham, C. N. R. Rao and R. K. Feller, Chem.
Commun., 2006, 4780–4795.
2
3
4
S. M. Cohen, Chem. Rev., 2012, 112, 970–1000.
Y. Cui, B. Li, H. He, W. Zhou, B. Chen and G. Qian, Acc Chem
Res, 2016, Ahead of Print.
5
6
7
K. B. Sezginel, S. Keskin and A. Uzun, Langmuir, 2016, 32,
1139–1147.
D. Freudenmann, S. Wolf, M. Wolff and C. Feldmann, Angew.
Chem. Int. Ed., 2011, 50, 11050–11060.
S. Zeng, X. Zhang, L. Bai, X. Zhang, H. Wang, J. Wang, D. Bao,
M. Li, X. Liu and S. Zhang, Chem. Rev., 2017, 117, 9625–9673.
After all the reactions, the catalysts were recovered and
analyzed by XRD and FT-IR spectroscopy. In addition, ICP-AES
spectroscopy and HR-TEM were used to corroborate that no
palladium leakage had occurred.
8 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 9 of 10
CrystEngComm
Please do not adjust margins
Journal Name
ARTICLE
8
9
K. Fujie and H. Kitagawa, Coord Chem Rev, 2016, 307, 382–
View Article Online
DOI: 10.1039/C9CE01157A
390.
Q. Luo, B. An, M. Ji and J. Zhang, Mater. Chem. Front., 2018,
2, 219–234.
10 F. P. Kinik, A. Uzun and S. Keskin, ChemSusChem, 2017, 10,
2842–2863.
11 Y. Chen, Z. Hu, K. M. Gupta and J. Jiang, J. Phys. Chem. C,
2011, 115, 21736–21742.
12 K. M. Gupta, Y. Chen, Z. Hu and J. Jiang, Phys. Chem. Chem.
Phys., 2012, 14, 5785–5794.
13 13 O. Tzialla, Ch. Veziri, X. Papatryfon, K. G. Beltsios, A.
Labropoulos, B. Iliev, G. Adamova, T. J. S. Schubert, M. C.
Kroon, M. Francisco, L. F. Zubeir, G. E. Romanos and G. N.
Karanikolos, J. Phys. Chem. C, 2013, 117, 18434–18440.
14 Y. Ban, Z. Li, Y. Li, Y. Peng, H. Jin, W. Jiao, A. Guo, P. Wang, Q.
Yang, C. Zhong and W. Yang, Angew. Chem. Int. Ed., 2015, 54,
15483–15487.
15 C. Casado-Coterillo, A. Fernández-Barquín, B. Zornoza, C.
Téllez, J. Coronas and Á. Irabien, RSC Adv., 2015, 5, 102350–
102361.
16 I. Cota and F. Fernandez Martinez, Coord. Chem. Rev., 2017,
351, 189–204.
17 S. Zhang, J. Zhang, Y. Zhang and Y. Deng, Chem. Rev., 2017,
117, 6755–6833.
18 J. Peng and Y. Deng, New J. Chem., 2001, 25, 639–641.
19 E.-H. Lee, S.-W. Cha, M. M. Dharma, Y. Choe, J.-Y. Ahn and
D.-W. Park, Korean J. Chem. Eng., 2007, 24, 547–550.
20 W. Lu, J. Ma, J. Hu, J. Song, Z. Zhang, G. Yang and B. Han,
Green Chem., 2013, 16, 221–225.
21 Y. Ma, C. Chen, T. Wang, J. Zhang, J. Wu, X. Liu, T. Ren, L.
Wang and J. Zhang, Appl. Catal. Gen., 2017, 547, 265–273.
22 J. Tharun, K.-M. Bhin, R. Roshan, D. W. Kim, A. C.
Kathalikkattil, R. Babu, H. Y. Ahn, Y. S. Won and D.-W. Park,
Green Chem., 2016, 18, 2479–2487.
23 D. Ma, B. Li, K. Liu, X. Zhang, W. Zou, Y. Yang, G. Li, Z. Shi and
S. Feng, J. Mater. Chem. A, 2015, 3, 23136–23142.
24 Q. Luo, M. Ji, S.-E. Park, C. Hao and Y. Li, RSC Adv., 2016, 6,
33048–33054.
25 M. Han, Z. Gu, C. Chen, Z. Wu, Y. Que, Q. Wang, H. Wan and
G. Guan, RSC Adv., 2016, 6, 37110–37117.
26 Z. Li, Y. Xiao, W. Xue, Q. Yang and C. Zhong, J. Phys. Chem. C,
2015, 119, 3674–3683.
27 27 W. Xue, Z. Li, H. Huang, Q. Yang, D. Liu, Q. Xu and C.
Zhong, Chem. Eng. Sci., 2016, 140, 1–9.
28 Y. Xie, Q. Sun, Y. Fu, L. Song, J. Liang, X. Xu, H. Wang, J. Li, S.
Tu, X. Lu and J. Li, J. Mater. Chem. A, 2017, 5, 25594–25600.
29 E. M. Maya, E. Verde-Sesto, D. Mantione, M. Iglesias and D.
Mecerreyes, Eur. Polym. J., 2019, 110, 107–113.
30 E. E. Macias, P. Ratnasamy and M. A. Carreon, Catal. Today,
2012, 198, 215–218.
31 F. Alonso and M. Yus, ACS Catal., 2012, 2, 1441–1451.
32 H. Li, M. Yang, Q. Pu, Micropor. Mesopor. Mater., 2012, 148,
166-173.
33 X. Li, D. Li, Y. Bai, C. Zhang, H. Chang, W. Gao, W. Wei,
Tetrahedron, 2016, 72, 6996-7002.
34 A. J. A. Watson and J. M. J. Williams, Science, 2010, 329,
635–636.
35 C. Gunanathan and D. Milstein, Science, 2013, 341, 1229712.
36 L. Jiang, L. Jin, H. Tian, X. Yuan, X. Yu and Q. Xu, Chem.
Commun., 2011, 47, 10833.
37 M. S. Kwon, S. Kim, S. Park, W. Bosco, R. K. Chidrala and J.
Park, J. Org. Chem., 2009, 74, 2877–2879.
38 L. Tang, H. Sun, Y. Li, Z. Zha and Z. Wang, Green Chem., 2012,
14, 3423.
39 S. M. A. Hakim Siddiki, T. Toyao and K. Shimizu, Green Chem.,
2018, 20, 2933–2952.
A. A. Yakovenko, Z. Wei, M. Wriedt, J.-R. Li, G. J. Halder and
H.-C. Zhou, Cryst. Growth Des., 2014, 14, 5397–5407.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 9
Please do not adjust margins

CrystEngComm
Page 10 of 10
View Article Online
Study of the versatility of CuBTC@IL derived materials for heterogeneous
DOI: 10.1039/C9CE01157A
catalysis
Edurne S. Larrea1*, Roberto Fernández de Luis2, Arkaitz Fidalgo-Marijuan2, Eva M.
Maya3, Marta Iglesias3, Maria I. Arriortua1,2
1 Dpto. Mineralogía y Petrología, Universidad del País Vasco, UPV/EHU, Sarriena s/n,
48940 Leioa, Spain; 2 BCMaterials (Basque Center for Materials, Applications &
Nanostructures), UPV/EHU Scientific Park, Martina Casiano Building, 3th floor, Sarriena
s/n, Leioa; 3 Instituto de Ciencia de Materiales de Madrid-CSIC, Sor Juana Inés de la
Cruz 3, Cantoblanco, 28049, Madrid, Spain.
The versatility of CuBTC (HKUST-1) MOF material to be functionalized for improving its catalytic
activity performance was evaluated. CuBTC@IL catalysts are selective for the cycloaddition of
CO2 to epoxides, giving rise to added-value products.