Synthesis of macroscopic monolithic metal-organic gels for ultra-fast destruction of chemical warfare agents

Article abstract of DOI:10.1039/d1ra01703a

The potential threat that has originated from chemical warfare agents (CWAs) has promoted the development of advanced materials to enhance the protection of civilian and military personnel. Zr-based metal-organic frameworks (Zr-MOFs) have recently been demonstrated as excellent catalysts for decomposing CWAs, but challenges of integrating the microcrystalline powders of Zr-MOFs into monoliths still remain. Herein, we report hierarchically porous monolithic UiO-66-X xerogels for the destruction of CWAs. We found that the UiO-66-NH₂xerogel with a larger pore size and a higher surface area than the UiO-66-NH₂powder possessed better degradability of 2-chloroethyl ethyl sulfide (2-CEES), which is a sulfur mustard simulant. These UiO-66-X xerogels exhibit outstanding performance for decomposing CWAs. The half-lives of vesicant agent sulfur mustard (HD) and nerve agentO-ethylS-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX) are as short as 14.4 min and 1.5 min, respectively. This work is, to the best of our knowledge, the first report on macroscopic monolithic UiO-66-X xerogels for ultrafast decomposition of CWAs.

Full text of DOI:10.1039/d1ra01703a

RSC Advances
View Article Online
View Journal | View Issue
PAPER
Synthesis of macroscopic monolithic metal–
organic gels for ultra-fast destruction of chemical
Cite this: RSC Adv., 2021, 11, 22125
warfare agents†
ab
ab
b
b
b
Chuan Zhou,
Cheng-an Tao
Shouxin Zhang,b
and Heguo Li*
Hongjie Pan, Guang Yang, Lingyun Wang,
c
The potential threat that has originated from chemical warfare agents (CWAs) has promoted the
development of advanced materials to enhance the protection of civilian and military personnel. Zr-
based metal–organic frameworks (Zr-MOFs) have recently been demonstrated as excellent catalysts for
decomposing CWAs, but challenges of integrating the microcrystalline powders of Zr-MOFs into
monoliths still remain. Herein, we report hierarchically porous monolithic UiO-66-X xerogels for the
destruction of CWAs. We found that the UiO-66-NH
surface area than the UiO-66-NH powder possessed better degradability of 2-chloroethyl ethyl sulfide
2-CEES), which is a sulfur mustard simulant. These UiO-66-X xerogels exhibit outstanding performance
for decomposing CWAs. The half-lives of vesicant agent sulfur mustard (HD) and nerve agent O-ethyl S-
2-(diisopropylamino)ethyl] methylphosphonothioate (VX) are as short as 14.4 min and 1.5 min,
2
xerogel with a larger pore size and a higher
2
(
Received 4th March 2021
Accepted 20th May 2021
[
DOI: 10.1039/d1ra01703a
respectively. This work is, to the best of our knowledge, the first report on macroscopic monolithic UiO-
rsc.li/rsc-advances
66-X xerogels for ultrafast decomposition of CWAs.
particular, Zr-based metal–organic frameworks (Zr-MOFs) have
attracted great research attention as potential heterogeneous
1
. Introduction
6
Chemical warfare agents (CWAs) such as sulfur mustard (HD) catalysts, due to their easy and numerous synthetic methods,
and VX are lethal chemicals that pose an extreme risk to and their exceptionally high thermal, chemical and mechanical
7
national security and public health, due to occasional or stabilities. Meanwhile, it has been demonstrated that Zr-MOFs
1
deliberate emissions. Detoxication of CWAs is an increasing such as MOF-808, PCN-777, NU-1000 and UiO-66-NH
2
have
research eld that has generated great interest from the scien- unprecedented catalytic degradation rates for nerve agents with
8
–10
tic and industrial communities. Current state-of-the-art half-lives of less than 0.5 min.
However, the crystallization of
materials for the capture of CWAs mainly rely on impregnated Zr-MOFs oen leads to microcrystalline powders. The applica-
active carbons, which suffer from problems such as slow tion of Zr-MOF powders is greatly hampered, due to their
2
degradation kinetics, low capacity, and/or a lack of tailorability.
inherent problems such as particle aggregation, poor process-
Thus, there is an urgent need to explore novel self-detoxifying ability and handling, mass transfer limitations, and signicant
11–15
materials to efficiently protect civilian and military personnel.
pressure drop in an adsorption bed.
To overcome the issues
Recently, resourceful studies have been carried out on the of Zr-MOF powders, many methods have been reported to
catalytic performance of the decontamination of CWAs. Among construct Zr-MOF macroscale structures by either integrating
1
6–18
them, metal–organic frameworks (MOFs) that are assembled by Zr-MOFs into support materials such as bers,
polymeric
19,20
21–23
metal ions or clusters with organic linkers through coordina- monoliths
and foams,
or pelletizing Zr-MOF powders via
24–26
tion bonds have been extensively studied and have shown mechanical compression or extrusion.
However, both
intriguing performances in CWA removal, due to their excep- strategies still have issues such as reduced adsorption capac-
tionally large surface area, high porosity, tunable textural and ities, due to the use of Zr-MOF as a secondary component, and
3
–5
chemical properties, and their abundant catalytic sites. In pressure-induced losses of crystallinity and porosity. Therefore,
the development of pure monolithic Zr-MOFs has become
a novel research eld in recent years.
Metal–organic gels (MOGs) linked by metal–ligand coordi-
nation associated with hydrogen bonding, hydrophobic effects,
p–p stacking and van der Waals interactions are a class of
fabricable, hierarchically porous, pure MOF materials.
Preparation of MOGs mainly depends on mismatched growth of
a
State Key Laboratory of NBC Protection for Civilians, Beijing 102205, PR China
b
Research Institute of Chemical Defense, Beijing 102205, PR China
c
College of Liberal Arts and Science, National University of Defense Technology,
Changsha 410073, China
27,28
†
Electronic supplementary information (ESI) available. See DOI:
0.1039/d1ra01703a
1
©
2021 The Author(s). Published by the Royal Society of Chemistry
RSC Adv., 2021, 11, 22125–22130 | 22125

View Article Online
RSC Advances
Paper
the MOF particles by regulating key factors such as synthesis instrument equipped with an alumina crucible and heated at
2
7
11
ꢀ
ꢁ1
ꢀ
temperature and time, reactant concentration, organic- a rate of 5 C min up to 800 C. N physisorption measure-
2
29
linker functionality and solvent in the gelation process. ments were measured at 77 K on a micromeritics ASAP 2020
Therefore, the combination of Zr-MOFs with a suitable gelation instrument. Prior to the measurements, the samples (20–40 mg)
ꢀ
process could shed light on Zr-MOF applications in the detox- were degassed for 8 h at 110 C and under 0.1 mbar vacuum.
ication of CWAs. Up to now, only sporadic examples involving Transmission electron microscopy (TEM) was performed on
Zr-based metal–organic gels (Zr-MOGs) have been reported. For a JEM-2100 microscope, operated in scanning mode (accelerating
example, the synthesis of Zr-MOGs from ZrCl
4
in a mixture of voltage of 200 kV). Scanning electron microscope (SEM) images
solvent/water proceeds through a rapid method at room were recorded on a JEOL JSM-IT300 microscope and were pro-
29
temperature. Bueken et al. described a series of Zr-MOGs cessed using the ImageJ soware. Inductively coupled plasma-
synthesized in DMF using ZrOCl $8H O as a precursor and optical emission spectroscopy (ICP-OES) and C, H and N
2
2
11
a mixture of HCl/AA as a modulator. However, there has been elemental analyses were carried out using a Leeman Prodigy 7 ICP-
almost no systematic or detailed investigation on the post- OES analyser and a Vario EL elemental analyser, respectively.
treatment of gel synthesis.
In this contribution, we systematically investigate the effect
that post-treatment conditions have on porosity for the opti-
mization and preparation of macroscopic monolithic UiO-66-X
2
.2. Synthesis of the UiO-66 xerogel
The UiO-66 xerogel was prepared under optimum conditions by
dissolving H BDC (5 mmol) and ZrOCl $8H O (7.25 mmol) in
xerogels (UiO-66 and UiO-66-NH xerogels). As far as we know,
2
2
2
2
DMF (30 mL) under sonication for 15 min. Aerwards, HCl (1.5
mL) and acetic acid (2.0 mL) as modulators were added to the
above solution, and the mixture was le for 5 min under soni-
cation. The resulting homogeneous solution was then allowed
to stand at 373 K for 2 h in a closed container to yield a thick
white UiO-66 gel. Subsequently, fresh DMF was added to the
above UiO-66 gel and was mixed well. The diluted gel suspen-
sion was centrifuged (5000 rpm, 5 min) and the supernatant was
decanted. The gel was then washed three times with ethanol
no report regarding UiO-66-X xerogels for the catalytic destruction
of real CWAs has appeared in the literature. Herein, we have rst
investigated the catalytic degradation performance of the UiO-66-
2 2
NH xerogel and the UiO-66-NH powder for use with 2-chloroethyl
ethyl sulde (2-CEES), which is a sulfur mustard simulant. Then,
we attempted to identify the sulfur mustard (HD) and VX decom-
position abilities of neat UiO-66-X xerogels at room temperature.
This is also the rst demonstration of ultra-fast destruction of
CWAs using Zr-MOFs xerogels.
ꢀ
and dried in air at 30 C. The obtained xerogel was immersed in
ꢀ
acetone and methanol for 12 h and dried in air at 30 C to
2
. Materials and methods
produce the macroscopic monolithic UiO-66 xerogel, as shown
in Fig. 1.
2.1. Chemicals and characterization methods
Unless otherwise noted, ACS reagent grade chemicals and
solvents were purchased from commercial vendors and were
2.3. Synthesis of the UiO-66-NH
2
xerogel
used without further purication. Terephthalic acid (H BDC), 2-
2
The UiO-66-NH xerogel was prepared by replacing H BDC in
2
2
aminoterephthalic acid (H N-BDC), zirconyl chloride octahy-
drate (ZrOCl $8H O) and 2-chloroethyl ethyl sulde (2-CEES)
2 2
2
the UiO-66 xerogel synthesis procedure with an equimolar
amount of H N-BDC.
2
were obtained from Shanghai Macklin Biochemical Co., Ltd.
Methanol, alcohol, acetone, N,N-dimethylformamide (DMF),
hydrochloric acid (37%) and acetic acid were obtained from
Shanghai Aladdin Chemicals Co., Ltd.
3
3
2
.4. Synthesis of the UiO-66-NH powder
2
2 2 2
ZrOCl $8H O (0.54 mmol), H N-BDC (0.75 mmol), 1 mL of HCl
Powder X-ray diffraction (PXRD) data were collected at room and 15 mL of DMF were added into a 100 mL Pyrex Schott bottle
temperature on a Bruker D2 Phaser diffractometer, with Cu K- before being sonicated for 10 min until fully dissolved. The
˚
ꢀ
alpha radiation (l ¼ 1.54178 A). Thermogravimetric analysis Pyrex Schott bottle was sealed and heated to 80 C for 12 h. The
TGA) was performed in air using a Mettler TGA/DSC 1 resulting pale yellow solid was centrifuged and washed three
(
Fig. 1 Schematic of the synthesis of the UiO-66 xerogel.
22126 | RSC Adv., 2021, 11, 22125–22130
© 2021 The Author(s). Published by the Royal Society of Chemistry

View Article Online
Paper
RSC Advances
times with DMF and alcohol. The sample was activated for 8 h residual 2-CEES or HD by GC-MS. 20 mL Pentane solution con-
ꢀ
in a vacuum oven at 110 C.
taining 0.4 mL VX was added to 20 mg xerogel in each glass vial.
Aerwards, the vials containing the reaction mixtures were
vortexed and were le standing at room temperature. Each vial
was taken out for analysis at regular times. The residual VX was
extracted in 2 mL of acetonitrile and the solution was subjected
to gas chromatography with an FID detector.
2
.5. Degradation experiments
Important! CWAs (HD, VX) are known to be lethal if inhaled or in
contact with skin. Experiments should be performed under/by
trained personnel in adequate facilities.
The catalytic degradation of 2-CEES, HD and VX was evalu-
ated. The degradation of 2-CEES and HD was carried out by
3
. Results and discussion
extraction: 25 mL CHCl solution containing 2.5 mL 2-CEES or
3
3.1. Xerogel optimization
HD was added to 25 mg xerogel in each glass vial, which were
vortexed and le standing for various periods of time before Based on the essential principle of optimising the porosity of
extracting with 3 mL ethanol for 3 times and analyzing for the xerogel, we selected UiO-66 as a prototype to perform
Fig. 2 Characterization of the xerogels. (a) XRD patterns; (b) TGA curves; (c) N
butions; (e) BJH pore size distributions.
2
adsorption–desorption isotherms; (d) NLDFT pore size distri-
RSC Adv., 2021, 11, 22125–22130 | 22127
©
2021 The Author(s). Published by the Royal Society of Chemistry

View Article Online
RSC Advances
Paper
a screening of several post-treatment parameters such as drying 40.6%, 40.3% and 37.5%, respectively (Fig. S1†). The calculated
temperature, washing procedure, centrifugation procedure and BDC ligands per unit of UiO-66-G, UiO-66-H and UiO-66-I were
metal-to-ligand ratio, in order to determine their inuence on 4.5, 4.4 and 4.1, respectively. Less BDC ligands means more
the porosity of the xerogel (Table S1†). Tian et al. noted that missing-linker defects, indicating that more defects exist in the
a low temperature of drying is benecial for the formation of the structural units of UiO-66-I, and this results in a higher specic
12
monolithic HKUST-1 gel. Subsequently, we investigated the surface area and pore volume.
effect of drying temperature on the porosity of the UiO-66
xerogel. The result showed that the Brunauer–Emmett–Teller
surface area (SBET) and the total pore volume (Vtot) of the xerogel
3.2. Structural and morphological characterizations
could be enhanced by appropriately increasing the drying Fig. 2a shows the XRD patterns of the monolithic UiO-66 xerogel
ꢀ
temperature (Table S1,† #1–#3). This may be due to the more and the UiO-66-NH xerogel. The apparent peaks at around 7
2
ꢀ
rapid solvent evaporation rate at a higher temperature, result- and 8.5 correspond well with the (111) and (200) reections of
ing in an increase in mesoporous content in the xerogel. We the UiO-66 structure. Furthermore, broad diffraction peaks
further evaluated the inuence of the washing procedure primarily originate from Scherrer broadening and nano-
33
(
washing solvents and washing times) on the porosity of the particles. The morphologies of the monolithic UiO-66 xerogel
ꢀ
UiO-66 xerogel by washing the gel before drying at 30 C. The and the UiO-66-NH xerogel are characterized by SEM and TEM.
2
result showed that the use of ethanol instead of DMF to wash The SEM images show a rough surface with closely packed
the UiO-66 gel helps to enhance the SBET and Vtot values of the nanoparticles, as seen in Fig. 3e–h. The TEM results further
xerogel (Table S1,† #1 vs. #5, #4 vs. #6). In addition, we found conrm that the monolith consists of compact nanoparticles
that SBET and Vtot of the xerogel could be signicantly increased with particle interstitial space (Fig. 3a–d). Elemental analysis
by increasing the number of ethanol washing times (Table S1,† shows that the experimental compositions of the UiO-66-X
#5 vs. #6), whereas the number of DMF washing times had little xerogels are signicantly different from their theoretical
signicant effect (Table S1,† #1 vs. #4). Furthermore, we exam- compositions (Table S2†), indicating the presence of defects, as
ined the effect of centrifugation time and found that a pro- illustrated by the lower experimentally observed carbon and
longed centrifugation time had no signicant effect on the nitrogen content relative to the theoretical content. In addition,
porosity of the xerogel (Table S1,† #1 vs. #7). A defect density the increase in hydrogen content of the experimental samples
3
0,31
would also greatly affect the porosity of the material.
a series of UiO-66 xerogels (Table S1,† UiO-66-G, UiO-66-H, UiO- TGA curve of the monolithic UiO-66-X xerogels is illustrated in
6-I) were synthesized by modulating different metal-to-ligand Fig. 2b. The high thermal stability of the monolith is consistent
Finally, may indicate the existence of water in the crystal structure. The
6
34
ratios, and these were characterized by TGA. All the synthe- with the previously reported literature. As shown in Fig. 2c, the
sized samples exhibited excellent thermal stability in air up to N adsorption–desorption isotherms are of Type IV, and this
2
ꢀ
5
00 C. The numbers of BDC linker in each unit of synthesized conrms the existence of a micro–mesoporous structure of the
UiO-66 xerogel could be calculated according to the amount of monolithic UiO-66 xerogel and of the UiO-66-NH xerogel. The
2
ꢀ
ꢀ
32
mass lost (%) between 300 C and 600 C. The mass loss (%) of Brunauer–Emmett–Teller surface areas (SBET), micro pore
the BDC linkers for UiO-66-G, UiO-66-H and UiO-66-I was volumes (W ) and total pore volumes (Vtot) are shown in Table
o
Fig. 3 Electron microscopy (top: low magnification; down: high magnification) images for the UiO-66-X xerogels. TEM images of the UiO-66
xerogel (a and b) and UiO-66-NH xerogel (c and d); SEM images of the UiO-66 xerogel (e and f) and UiO-66-NH (g and h) xerogel.
2 2
22128 | RSC Adv., 2021, 11, 22125–22130
© 2021 The Author(s). Published by the Royal Society of Chemistry

View Article Online
Paper
RSC Advances
2
Fig. 4 Degradation of 2-CEES on the UiO-66-NH xerogel and on the
UiO-66-NH powder.
2
Fig. 6 Degradation of VX on the UiO-66 xerogel and on the UiO-66-
2
NH xerogel.
S3.† Interestingly, these experimental values are higher than the
theoretical maxima, and this may be related to the presence of
extensive mesoporosity in the xerogels. The NLDFT analysis
conrms the microporosity (Fig. 2d), while the BJH pore size
distribution signicantly highlights the extensive mesoporosity
of between 5 and 20 nm (Fig. 2e). The mesoporosity of the
xerogels is not generated by crystalline defects, but corresponds
to interparticle voids.
xerogel exhibits a faster reaction rate, with a half-life of 8.2 min,
than the UiO-66-NH powder that exhibits a t value of 29 min.
This nding can be attributed to the larger pore size and higher
surface area of the UiO-66-NH xerogel, allowing for 2-CEES
molecules to diffuse more rapidly and/or access more active
sites.
2
1/2
2
In addition to the simulant 2-CEES, we further tested our
monolithic UiO-66-X xerogels on the hydrolytic degradation of
HD, a real CWA (Fig. 5). As is well-known, Zr-based metal–
organic frameworks (Zr-MOFs) are highly active in the decom-
position of P–X bonds (X ¼ F, Cl, S, O) of nerve agents, but they
are poorly active in the destruction of C–Cl of vesicant agents.
This limits the practical application of Zr-MOFs for the degra-
dation of unknown chemical threats. In this regard, we have
found that the incorporation of an amino-group leads to
signicant improvement of the degradation of C–Cl bonds
3
.3. Degradation properties
In order to understand the effect of state on the decomposition
of CWAs, a decomposition experiment for 2-CEES was imple-
mented at room temperature. Data for the structural charac-
terization of the UiO-66-NH
shows the decomposition rates of 2-CEES over time on the UiO-
6-NH xerogel and UiO-66-NH powder. The UiO-66-NH
2
2
powder are given in Fig. S2.† Fig. 4
6
2
2
found in HD. For the UiO-66-NH xerogel, we observed 100%
2
HD conversion in 240 min of reaction. The UiO-66-NH xerogel
2
(
t1/2 ¼ 14.4 min) shows a faster destruction rate compared to the
pristine UiO-66 xerogel (t1/2 ¼ 24.8 min).
To further investigate the catalytic performance of our
materials, we also evaluated the behavior of the xerogels for the
hydrolytic degradation of nerve agent VX. In this regard, it
should be noted that both of the xerogels exhibited rapid VX
degradation (t1/2 # 1.5 min) and 100% conversion within 3 min
(Fig. 6). There was little difference in the VX decomposing
ability for the UiO-66 and UiO-66-NH xerogels. This discovery is
2
10
in accordance with the previous report of Ryu et al. who
studied the detoxication of GD on UiO-66 and UiO-66-NH
2
powders.
4. Conclusions
In summary, UiO-66-X xerogels have been prepared and studied
for the degradation of CWAs. The results indicate that the UiO-
Fig. 5 Degradation of HD on the UiO-66 xerogel and on the UiO-66-
NH xerogel.
2
©
2021 The Author(s). Published by the Royal Society of Chemistry
RSC Adv., 2021, 11, 22125–22130 | 22129

View Article Online
RSC Advances
6-NH
Paper
6
2
xerogel (t1/2 ¼ 8.2 min) displays excellent catalytic 13 S. M. F. Vilela, P. Salcedo-Abraira, L. Micheron, E. L. Solla,
performance for the degradation of 2-CEES compared to the
P. G. Yot and P. Horcajada, Chem. Commun., 2018, 54,
13088–13091.
UiO-66-NH2 powder (t1/2 ¼ 29 min). Using these UiO-66-X
xerogels shortens the half-lives of HD and VX to 14.4 min and 14 W. Cui, X. Kang, X. Zhang and X. Cui, J. Phys. Chem. Solids,
1
.5 min, respectively. We also conrmed that there is little
obvious degradability difference between the UiO-66 and UiO- 15 J. Hou, A. F. Sapnik and T. D. Bennett, Chem. Sci., 2020, 11,
6-NH xerogels for nerve agents in actual situations. This 310–323.
contribution shows that Zr-MOFs xerogels have remarkable 16 D. B. Dwyer, N. Dugan, N. Hoffman, D. J. Cooke, M. G. Hall,
2019, 134, 165–175.
6
2
prospects for use in future CWA protective applications.
T. M. Tovar, W. E. Bernier, J. DeCoste, N. L. Pomerantz and
W. E. Jones, Jr, ACS Appl. Mater. Interfaces, 2018, 10, 34585–
3
4591.
Conflicts of interest
1
7 H. Liang, A. Yao, X. Jiao, C. Li and D. Chen, ACS Appl. Mater.
Interfaces, 2018, 10, 20396–20403.
There are no conicts to declare.
18 D. L. McCarthy, J. Liu, D. B. Dwyer, J. L. Troiano, S. M. Boyer,
J. B. DeCoste, W. E. Bernier and W. E. Jones, Jr, New J. Chem.,
Acknowledgements
2
017, 41, 8748–8753.
This work was nancially supported by the State Key Laboratory
of NBC Protection for Civilian Foundation of China
1
2
2
9 Y. Hara, K. Kanamori and K. Nakanishi, Angew. Chem., Int.
Ed., 2019, 58, 19047–19053.
0 Y. Dong, L. Cao, J. Li, Y. Yang and J. Wang, RSC Adv., 2018, 8,
3
(SKLNBC201807) and by the National Natural Science Founda-
tion of China (No. 22075319). The authors also acknowledge the
Analytical Instrumentation Center of Peking University.
2358–32367.
1 J. Zhao, L. Xu, Y. Su, H. Yu, H. Liu, S. Qian, W. Zheng and
Y. Zhao, J. Environ. Sci., 2021, 101, 177–188.
References
22 L. Wen, X. Chen, C. Chen, R. Yang, M. Gong, Y. Zhang and
Q. Fu, Arabian J. Chem., 2020, 13, 5669–5678.
1
M. Zhang, Y. Liu, J. Chen, H. Liu, X. Lu, J. Wu, Y. Zhang,
Y. Lin, Q. Liu, H. Wang, L. Guo, R. Gao, B. Xu and J. Xie,
Anal. Chem., 2020, 92, 10578–10587.
2
3 D. Xie, Y. Gu, H. Wang, Y. Wang, W. Qin, G. Wang, H. Zhang
and Y. Zhang, J. Colloid Interface Sci., 2019, 542, 269–280.
4 Y. Khabzina, J. Dhainaut, M. Ahlhelm, H. J. Richter,
H. Reinsch, N. Stock and D. Farrusseng, Ind. Eng. Chem.
Res., 2018, 57, 8200–8208.
2
2
3
4
S. S. Mondal and H. J. Holdt, Angew. Chem., Int. Ed., 2016, 55,
4
2–44.
J. B. DeCoste and G. W. Peterson, Chem. Rev., 2014, 114,
695–5727.
2
5 L. R. Redfern, L. Robison, M. C. Wasson, S. Goswami, J. Lyu,
T. Islamoglu, K. W. Chapman and O. K. Farha, J. Am. Chem.
Soc., 2019, 141, 4365–4371.
5
I. Stassen, B. Bueken, H. Reinsch, J. F. M. Oudenhoven,
D. Wouters, J. Hajek, V. Van Speybroeck, N. Stock,
P. M. Vereecken, R. Van Schaijk, D. De Vos and
R. Ameloot, Chem. Sci., 2016, 7, 5827–5832.
2
2
2
6 D. W. Lee, T. Didriksen, U. Olsbye, R. Blom and C. A. Grande,
Sep. Purif. Technol., 2020, 235, 116182–116193.
7 L. Li, S. Xiang, S. Cao, J. Zhang, G. Ouyang, L. Chen and
C. Y. Su, Nat. Commun., 2013, 4, 1774–1782.
8 A. Carne-Sanchez, G. A. Craig, P. Larpent, T. Hirose,
M. Higuchi, S. Kitagawa, K. Matsuda, K. Urayama and
S. Furukawa, Nat. Commun., 2018, 9, 2506–2513.
5
6
T. Islamoglu, Z. Chen, M. C. Wasson, C. T. Buru,
K. O. Kirlikovali, U. Afrin, M. R. Mian and O. K. Farha,
Chem. Rev., 2020, 120, 8130–8160.
C. Zhou, B. Yuan, S. Zhang, X. Yang and J. Zhong, Chem. Ind.
Eng. Prog., 2019, 38, 4614–4622.
2
9 J. Santos-Lorenzo, R. San Jos ´e -Velado, J. Albo, G. Beobide,
P. Casta n˜ o, O. Castillo, A. Luque and S. P ´e rez-Y ´a n˜ ez,
Microporous Mesoporous Mater., 2019, 284, 128–132.
0 X. Zhang, Y. Yang, L. Song, J. Chen, Y. Yang and Y. Wang, J.
Hazard. Mater., 2019, 365, 597–605.
1 C. Yin, Q. Liu, R. Chen, J. Liu, J. Yu, D. Song and J. Wang, Ind.
Eng. Chem. Res., 2019, 58, 1159–1166.
2 H. Wu, Y. S. Chua, V. Krungleviciute, M. Tyagi, P. Chen,
T. Yildirim and W. Zhou, J. Am. Chem. Soc., 2013, 135,
7
8
M. Taddei, Coord. Chem. Rev., 2017, 343, 1–24.
M. C. de Koning, M. van Grol and T. Breijaert, Inorg. Chem.,
2017, 56, 11804–11809.
3
3
3
9
J. M. Palomba, C. V. Credille, M. Kalaj, J. B. DeCoste,
G. W. Peterson, T. M. Tovar and S. M. Cohen, Chem.
Commun., 2018, 54, 5768–5771.
1
0 S. G. Ryu, M.-K. Kim, M. Park, S. O. Jang, S. H. Kim and
H. Jung, Microporous Mesoporous Mater., 2019, 274, 9–16.
1 B. Bueken, N. Van Velthoven, T. Willhammar, T. Stassin,
I. Stassen, D. A. Keen, G. V. Baron, J. F. M. Denayer,
R. Ameloot, S. Bals, D. De Vos and T. D. Bennett, Chem.
Sci., 2017, 8, 3939–3948.
1
10525–10532.
3
3
3 M. J. Katz, Z. J. Brown, Y. J. Colon, P. W. Siu, K. A. Scheidt,
R. Q. Snurr, J. T. Hupp and O. K. Farha, Chem. Commun.,
2013, 49, 9449–9451.
1
2 T. Tian, Z. Zeng, D. Vulpe, M. E. Casco, G. Divitini,
P. A. Midgley, J. Silvestre-Albero, J. C. Tan,
P. Z. Moghadam and D. Fairen-Jimenez, Nat. Mater., 2018,
4 J. Ren, H. W. Langmi, B. C. North, M. Mathe and
D. Bessarabov, Int. J. Hydrogen Energy, 2014, 39, 890–895.
17, 174–179.
22130 | RSC Adv., 2021, 11, 22125–22130
© 2021 The Author(s). Published by the Royal Society of Chemistry