Tuning the growth of Cu-MOFs for efficient catalytic hydrolysis of carbonyl sulfide

Article abstract of DOI:10.1016/S1872-2067(17)62874-2

Development of the high activity, promoter-free catalysts for carbonyl sulfide (COS) hydrolysis is important for the efficient utilization of various feedstocks. In this study, the Cu-based metal-organic framework HKUST-1 is synthesized by a simple and mild anodic-dissolution electrochemical method. The physical and chemical properties of the samples are characterized by several techniques, including scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller analysis and X-ray photoelectron spectroscopy. The results reveal that the synthesis voltage plays a crucial role in controlling the morphology of the resulting HKUST-1. The obtained samples function as novel catalysts for the hydrolysis of COS. A high efficiency, approaching 100%, can be achieved for the conversion of COS at 150 °C over the optimal HKUST-1 synthesized at 25 V. This is significantly higher than that of the sample prepared by the traditional hydrothermal method. Additionally, the effects of the water temperature and the flow velocity on the hydrolysis of COS are also investigated in detail. Finally, a possible reaction pathway of COS hydrolysis over HKUST-1 is also proposed. This work represents the first example of MOFs applied to the catalytic hydrolysis of COS. The results presented in this study can be anticipated to give a feasible impetus to design novel catalysts for removing the sulfur-containing compounds.

Full text of DOI:10.1016/S1872-2067(17)62874-2

Chinese Journal of Catalysis 38 (2017) 1373–1381
a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m
j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / c h n j c
Article
Tuning the growth of Cu‐MOFs for efficient catalytic hydrolysis of
carbonyl sulfide
Lijuan Shen, Gaojie Wang, Xiaoxiao Zheng, Yanning Cao, Yufeng Guo, Ke Lin, Lilong Jiang*
National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou 350002, Fujian, China
A R T I C L E I N F O
A B S T R A C T
Article history:
Development of the high activity, promoter‐free catalysts for carbonyl sulfide (COS) hydrolysis is
important for the efficient utilization of various feedstocks. In this study, the Cu‐based met‐
al‐organic framework HKUST‐1 is synthesized by a simple and mild anodic‐dissolution electro‐
chemical method. The physical and chemical properties of the samples are characterized by several
techniques, including scanning electron microscopy, X‐ray diffraction, Brunauer‐Emmett‐Teller
analysis and X‐ray photoelectron spectroscopy. The results reveal that the synthesis voltage plays a
crucial role in controlling the morphology of the resulting HKUST‐1. The obtained samples function
as novel catalysts for the hydrolysis of COS. A high efficiency, approaching 100%, can be achieved
for the conversion of COS at 150 ºC over the optimal HKUST‐1 synthesized at 25 V. This is signifi‐
cantly higher than that of the sample prepared by the traditional hydrothermal method. Additional‐
ly, the effects of the water temperature and the flow velocity on the hydrolysis of COS are also inves‐
tigated in detail. Finally, a possible reaction pathway of COS hydrolysis over HKUST‐1 is also pro‐
posed. This work represents the first example of MOFs applied to the catalytic hydrolysis of COS.
The results presented in this study can be anticipated to give a feasible impetus to design novel
catalysts for removing the sulfur‐containing compounds.
Received 11 April 2017
Accepted 17 June 2017
Published 5 August 2017
Keywords:
Metal‐organic framework
Carbonyl sulfide
Electrochemical synthesis
Catalytic hydrolysis
HKUST‐1
© 2017, Dalian Institute of Chemical Physics, Chinese Academy of Sciences.
Published by Elsevier B.V. All rights reserved.
1. Introduction
to remove COS [7]. Among them, hydrolysis (COS + H2O → H2S
+ CO2) is recognized as the most promising process by virtue of
Sulfur compounds are frequently present in petroleum gas,
water gas, and natural gas, where they not only corrode reac‐
tion equipment and deactivate catalysts but also cause damage
to the environment as major sources of acid rain [1–4]. In par‐
ticular, carbonyl sulfide (COS) is probably the most long‐lived
sulfur gas because of its chemical stability [5,6]. In view of both
increasingly stringent environmental regulations and the tech‐
nical requirements of further catalytic processes, the removal
of COS is of high urgency. Several methods, including adsorp‐
tion, reduction, oxidation and hydrolysis, have been developed
its mild reaction conditions and high conversion efficiency
[8,9]. Previous studies have been devoted to the development
of catalysts for COS hydrolysis, mostly focusing on metal oxides
like titania and alumina [10–12]. In order to improve the activi‐
ties of these catalysts, alkali earth metals, transition metal ox‐
ides (Co, Cu, Ni, Fe, Zn) and rare earth metal oxides are often
used as promoters [13–15]. Additionally, carbon materials have
been reported as promising catalysts for COS hydrolysis. For
example, Ning et al. [16] reported that in the hydrolysis of COS
over activated carbon, the catalytic activity was enhanced by
* Corresponding author. Tel: +86‐591‐83731234; E‐mail: jll@fzu.edu.cn
This work was supported by the National Natural Science Foundation of China (21603034, 21576051) and the National High Technology Research
and Development Program of China (863 Program, 2015AA03A402).
DOI: 10.1016/S1872‐2067(17)62874‐2 | http://www.sciencedirect.com/science/journal/18722067 | Chin. J. Catal., Vol. 38, No. 8, August 2017

1374
Lijuan Shen et al. / Chinese Journal of Catalysis 38 (2017) 1373–1381
adding Fe, Cu, Ni or Ce promoters. Although these systems have
beneficial features, the search for new catalysts with high activ‐
ity and without the need for promoters remains an active re‐
search challenge.
Copper rod (19 mm diam, 56 g, purity = 99.9998%) as elec‐
trode material and tetrabutylammonium perchlorate (TBAP;
purity > 99%) as supporting electrolyte were purchased from
Sigma Aldrich Co., Ltd. (Shanghai, China). 1,3,5‐Benzenetricar‐
boxylic acid (H3BTC; purity >99%) was supplied by Beijing
Lark Technology Co., Ltd., China. Ethanol (C2H5OH) was pur‐
chased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai,
China). Deionized (DI) water was obtained from local sources.
All of the above chemicals were used as received and without
further purification.
Among various materials, metal‐organic frameworks
(MOFs), which are assembled by combining metal ions/clusters
with organic ligands, have attracted particular attention
[17–19]. The unique features of MOFs, such as high pore vol‐
umes, high specific surface areas and structural flexibility,
make them attractive candidates for applications including
adsorption [20–22], separation [23], chemical sensing and drug
release [24,25]. In particular, MOFs are promising in the field of
catalysis [26–31]. Their accessible open‐metal centers, as well
as functional groups incorporated into the linkers, can function
as active sites, endowing them with catalytic properties. Dis‐
tinct from conventional catalysts, MOFs can be synthesized
from materials with well‐defined crystalline structures. This is
beneficial for the characterization of these catalysts and may
provide new opportunities for a deep study of their struc‐
ture‐property relationships. Moreover, the properties of MOFs
can be facilely controlled through the modification of the metal
center or organic linker because of their adaptable chemistry,
enabling them to be easily tailored to meet specific needs
[32–34]. Despite the rapidly growing interest in MOFs, howev‐
er, to the best of our knowledge, no previous work regarding
their application for the catalytic hydrolysis of COS has been
reported.
2.1.2. Synthesis of HKUST‐1 by electrochemical method
Two copper electrodes were used as anode and cathode,
respectively, for the synthesis of HKUST‐1. The organic linker
(1.75 g H3BTC) and supporting electrolyte (2.85 g TBAP) were
dissolved in 240 mL ethanol/water (3:1) solution. Electrolysis
was carried out in a self‐contained electrochemical cell under
constant voltages (15, 20, 25 and 30 V) that were held for 3 h,
following which products blue in color were obtained. After
that, the samples were washed three times with water and
ethanol separately, and then dried in an oven at 100 °C for 24 h.
Finally, a series of HKUST‐1 samples was obtained. According
to the voltage used during the synthesis, the obtained samples
were named as HKUST‐1‐E15, HKUST‐1‐E20, HKUST‐1‐E25
and HKUST‐1‐E30, respectively.
2.1.3. Synthesis of HKUST‐1 by solvothermal method
Herein, we report the synthesis of the Cu‐based MOF
HKUST‐1 by the anodic‐dissolution method and its application
for COS hydrolysis. HKUST‐1 is constructed by Cu2+ ions coor‐
dinated to the 1,3,5‐benzenetricarboxylate ligand, forming a
3D, porous, square‐shaped (0.9 nm × 0.9 nm) structure [35,36].
HKUST‐1 is chosen as the target of research for several reasons.
First, the proper pore sizes are ideal for the adsorption and
diffusion of COS molecules. Second, the coordinatively unsatu‐
rated copper centers and the high stability of HKUST‐1 are
beneficial for catalysis. Finally, the synthesis of HKUST‐1 re‐
quires only inexpensive copper sources and trimesic acid, and
it is already commercially available, suggesting that HKUST‐1
could fulfill the requirements for industrial use [37]. Compared
with the traditional methods, which require high energy con‐
sumption and long reaction time, the electrochemical synthesis
consumes less energy while effectively shortening the reaction
time (from a matter of days to a few hours). More significantly,
it offers the ability to influence the reaction directly in real‐
time, allowing more control of the reaction throughout the
process [38–40]. Herein, the synthesis of HKUST‐1 is controlled
by varying the synthesis voltage, and the product is structurally
characterized by XRD, SEM, BET and XPS. It is found that the
as‐synthesized samples exhibit excellent activity for the cata‐
lytic hydrolysis of COS.
For comparison purposes, HKUST‐1 was also prepared by
the solvothermal method [41]. Cu(NO3)2·3H2O (2.077 g) was
dissolved in 15 mL deionized water. Separately, H3BTC (1.00 g)
was dissolved in 30 mL N,N‐dimethylformamide/ethanol solu‐
tion (1:1). Then, the above two solutions were mixed and
stirred for 10 min. After that, the mixture was transferred to a
70 mL Teflon‐lined stainless‐steel autoclave, then heated to
100 °C and held for 12 h. After cooling to room temperature, it
was filtered and washed three times with water and ethanol
separately, and then dried in an oven at 100 °C for 24 h. The
obtained sample was named as HKUST‐1‐Hy.
2.2. Characterizations
The as‐synthesized HKUST‐1 was characterized by X‐ray
diffraction (XRD, X’Pert PRO) using Co Kα radiation (λ = 0.1790
nm), with a voltage of 40 kV and current of 40 mA. The mor‐
phologies and microstructures of HKUST‐1 were studied by
scanning electron microscope (SEM, S‐4800, Hitachi, Japan)
analysis. The Brunauer‐Emmett‐Teller (BET) surface areas and
average pore diameters of the HKUST‐1 were measured by N2
adsorption‐desorption using an ASAP 2020 instrument (Mi‐
cromeritics, USA). FT‐IR spectra were recorded over a Nicolet
6700 spectrometer (Thermo Fisher Scientific) with an MCT
detector. Nitrogen was introduced into the IR cell as the back‐
ground. The spectra were obtained in the 4000–800 cm−1 range
at a resolution of 2.0 cm−1 with 32 scans. X‐ray photoelectron
spectroscopy (XPS) measurements were performed over a PHI
Quantum 2000 XPS system.
2. Experimental
2.1. Preparation
2.1.1. Materials

Lijuan Shen et al. / Chinese Journal of Catalysis 38 (2017) 1373–1381
1375
2.3. Evaluation of catalytic activity
provides a higher concentration of Cu2+ around the copper an‐
ode.
The hydrolysis of COS over HKUST‐1 was performed in a
fixed‐bed reactor at atmospheric pressure. 0.4 g catalyst was
used. At steady state, a mixture gas of N2 containing COS (100
mg/m3) was introduced into the reactorat a total flow rate of
30 mL/min. H2O was injected from a thermostatic water bath
through a controlled saturator. By adjusting the temperature of
the water bath, the relative humidity of the reaction gas was
controlled. The concentration of COS in the reactor effluent was
monitored on‐line by a gas chromatograph (Shimadzu GC
2014) equipped with a flame photometric detector. The con‐
version of COS was determined by analyzing the initial and the
current temperature‐peak areas of COS in the GC. In this study,
the COS conversion was calculated as follows:
3.2. XRD
Fig. 2 shows the powder XRD patterns of HKUST‐1 synthe‐
sized at different voltages. The diffraction peaks of all the
as‐synthesized HKUST‐1 samples match the simulated pattern,
confirming the successful synthesis of HKUST‐1 by electro‐
chemical anodic dissolution. With the increase of the voltage
from 15 to 25 V, the intensity of the diffraction peaks of the
samples gradually increases. The sharp diffraction peaks of
HKUST‐1‐E25 indicate its high crystallinity. With the further
increase of the voltage to 30 V, the diffraction peaks of
HKUST‐1‐E30 decrease in intensity. Moreover, additional peaks
are observed, which possibly arise from the formation of a
small amount of Cu2O [42]. Comparing the four samples of
HKUST‐1, the dominant facets are found to be slightly different
in each case. As is known, the growth of crystals is coordinated
by the cooperative growth of some planes at slower speeds and
others at faster speeds, and the exposed facets of the crystal are
generally the slower‐growing planes [43]. The above results
indicate the significant influence of the voltage on the growth of
these MOF crystals. This is in good agreement with the SEM
results.
COS conversion (%) = (C0− CT) / C0 × 100
where C0 and CT are the peak area of COS at temperatures of 30
°C and T °C, respectively.
3. Results and discussion
3.1. SEM
The morphologies and microstructures of HKUST‐1 were
investigated by SEM. As shown in Fig. 1, the synthesis voltage of
the reaction system greatly affected the morphologies of
HKUST‐1. HKUST‐1‐E15 shows a rod‐like morphology with rod
lengths of about 15 μm. As the voltage increases, the structure
becomes progressively shorter, and the rod‐like morphology
gradually transforms to an octahedral shape for the sample of
HKUST‐1‐E25. With the further increase of the voltage to 30 V,
the crystal size of HKUST‐1‐E30 decreases and the particles
aggregate into an irregular structure. Note that the particle
sizes of the HKUST‐1 samples synthesized electrochemically
are non uniform. This may have arisen from the concentration
gradient of Cu2+ in the reaction system, whereby the electrolyte
3.3. BET
Fig. 3 shows the N2 adsorption‐desorption isotherms and
pore size distributions of HKUST‐1 synthesized at different
voltages. The type I adsorption isotherm of HKUST‐1‐E15 sug‐
gests the existence of micropores in this sample. For
HKUST‐1‐E20 and HKUST‐1‐E25, it can be seen that besides the
adsorption capacity in the area of low pressure, both samples
also display a hysteresis loop in the areas of medium and high
pressure. The curves show the properties of I/IV mixed‐type
isotherms, indicating the presence of micropores and meso‐
(b)
(a)
5 μm
(1)
5 μm
(2)
(3)
(c)
(d)
(4)
(5)
5
10
15
20
25
30
35
40
45
50
5 μm
5 μm
2 ()
Fig. 1. SEM images of HKUST‐1‐E15 (a), HKUST‐1‐E20 (b),
Fig. 2. XRD patterns of HKUST‐1‐E15 (1), HKUST‐1‐E20 (2),
HKUST‐1‐E25 (c) and HKUST‐1‐E30 (d).
HKUST‐1‐E25 (3), HKUST‐1‐E30 (4), and simulated HKUST‐1 (5).

1376
Lijuan Shen et al. / Chinese Journal of Catalysis 38 (2017) 1373–1381
(a)
(b)
0.5
0.4
0.3
0.2
0.1
0.0
(2)
(3)
(3)
(1)
(1)
(4)
(2)
(4)
0.0
0.2
0.4
0.6
0.8
1.0
0
20
40
60
80
100
Relative pressure (p/p0)
Pore diameter (nm)
Fig. 3. N2 adsorption‐desorption isotherms (a) and pore size distributions (b) of HKUST‐1‐E15 (1), HKUST‐1‐E20 (2), HKUST‐1‐E25 (3), and
HKUST‐1‐E30 (4).
pores. The mesopores of HKUST‐1‐E20 and HKUST‐1‐E25 are
thought to be formed by the loose accumulation of HKUST‐1
particles. For the sample of HKUST‐1‐E30, a type I microporous
sorption isotherm is observed.
reaching the adsorption–desorption equilibrium, which ex‐
cludes the possibility that the mere adsorption of COS on
HKUST‐1 is responsible for its removal. In the presence of
HKUST‐1 catalyst, the COS is efficiently converted, as shown in
Fig. 4. Increasing the reaction temperature results in an im‐
provement of the COS conversion efficiency for each catalyst. At
30 °C, negligible COS conversion is obtained over all the
HKUST‐1 samples. When the temperature is increased to 150
°C, about 38% of the COS is hydrolyzed over HKUST‐1‐E15.
Moreover, with increasing synthesis voltage, the catalytic activ‐
ities of the obtained HKUST‐1 are found to increase markedly.
HKUST‐1‐E25 shows the highest activity, achieving a COS con‐
version efficiency of 98% at 150 °C. This conversion efficiency
is also higher than that of the HKUST‐1‐Hy sample, which was
prepared by the hydrothermal method. When the synthesis
voltage was further increased to 30 V, the obtained
HKUST‐1‐E30 sample shows much poorer activity, with a COS
hydrolysis conversion efficiency of only 20%. This variation of
catalytic activity with synthesis voltage may have been caused
The corresponding textural parameters calculated from the
N2 adsorption‐desorption isotherms are listed in Table 1. The
BET surface area and pore volume of HKUST‐1‐E15 are 616
m2/g and 0.17 cm3/g, respectively, within the range of values
reported in the literature [44]. As the voltage increases, the
BET surface areas of the HKUST‐1 increase. The BET surface
areas are 738 and 786 m2/g for HKUST‐1‐E20 and
HKUST‐1‐E25, respectively. When further increasing the volt‐
age to 30 V, the BET surface area of the obtained HKUST‐1‐E30
decreases to 405 m2/g. These changes can be mainly attributed
to the morphological and structural transformation of HKUST‐1
with increasing voltage. It is expected that the HKUST‐1 cata‐
lysts with greater specific surface area will be able to supply
more surface active sites for the adsorption of COS, leading to
enhanced catalytic performance.
100
3.4. COS hydrolysis performance
(3)
The catalytic performance of the as‐synthesized HKUST‐1
for the hydrolysis of COS was investigated at temperatures
ranging from 30 to 150 °C. Before testing, control experiments
were first carried out to verify the catalytic nature of the reac‐
tions. A blank experiment in the absence of catalyst led to no
conversion of COS. Additionally, an experiment in the presence
of catalyst was carried out at a constant temperature of 30 °C
for 12 h. No obvious removal of COS was measured after
80
60
40
20
0
(2)
(5)
(1)
(4)
Table 1
Textural properties of HKUST‐1 synthesized at different voltages.
20
40
60
80
100
120
140
160
ABET
(m2/g)
616
738
786
Pore volume
(cm3/g)
0.17
Average pore
size (nm)
3.54
Temperature (oC)
Sample
HKUST‐1‐E15
HKUST‐1‐E20
HKUST‐1‐E25
HKUST‐1‐E30
Fig. 4. COS hydrolysis over HKUST‐1‐E15 (1), HKUST‐1‐E20 (2),
HKUST‐1‐E25 (3), HKUST‐1‐E30 (4), and HKUST‐1‐Hy (5). Reaction
conditions: catalyst mass 0.4 g, feed gas 100 mg/cm3 COS/N2, WHSV
4500 h−1, water temperature 40 °C.
0.31
0.27
0.13
14.84
10.65
2.86
405

Lijuan Shen et al. / Chinese Journal of Catalysis 38 (2017) 1373–1381
1377
by the corresponding structural changes of the HKUST‐1. The
100
80
60
40
20
0
products of the reaction included H2S, as determined by chro‐
matographic analysis. Moreover, the outlet gas was further
collected and analyzed by IR spectroscopy. Absorption bands
assigned to the (ʋ)3 mode of CO2 were observed, confirming
that the catalytic hydrolysis reaction had occurred [45]. To
deduce the catalytic sites of HKUST‐1, the catalytic activity of
H3BTC was also evaluated. In this case, the reaction did not
proceed when an equivalent mass of H3BTC was employed as a
substitute for HKUST‐1, suggesting that the open Cu sites (i.e.,
Cu2+) of the HKUST‐1 are the catalytic sites.
25C
40 C
60 C
3.5. Effect of the supporting electrolyte
20
40
60
80
100
120
140
160
Temperature (oC)
It is known that the synthesis parameters can affect the
morphology and chemical properties of the resulting material.
Therefore, besides the voltage, the influence of the supporting
electrolyte on the growth of HKUST‐1 was also investigated. A
series of HKUST‐1 was prepared at constant voltage (25 V)
with different amounts of TBAP supporting electrolyte. The
SEM analysis shows that these samples display a similar octa‐
hedral shape, with no significant differences in morphology
among the three samples. The catalytic performance of this
series of HKUST‐1 was then evaluated, as shown in Fig. 5. The
COS conversion efficiencies of the three samples are almost
identical at all reaction temperatures: all three improve with
increasing temperature and finally reach almost 100% at 150
°C, suggesting that the amount of supporting electrolyte has no
obvious influence on the morphology and catalytic ability of
HKUST‐1.
Fig. 6. Influence of water temperature on COS conversion over
HKUST‐1‐E25. Reaction conditions: catalyst mass 0.4 g, feed gas 100
mg/cm3 COS /N2, WHSV 4500 h−1.
HKUST‐1‐E25 sample. As shown in Fig. 6, when the water tem‐
perature is 25 °C, the COS conversion efficiency is only about
70% at 150 °C because of the insufficient availability of water
to participate in the reaction. When the water temperature is
increased to 40 °C, nearly 100% COS is converted. However,
further increasing the water temperature leads to decreased
activity. When the water temperature is increased to 60 °C, the
conversion efficiency of COS falls to 65%. This can be ascribed
to the competitive adsorption between COS and H2O on the
surface of the catalyst. Excess water inhibits the chemisorption
of COS, thus reducing the activity of the catalyst [46]. This re‐
sult confirms that water temperature is a strongly influential
factor on the hydrolysis of COS.
3.6. Effect of the water temperature
3.7. Effect of the flow velocity
As a reactant, the amount of water has a direct influence on
the hydrolysis reaction. This can be adjusted by controlling the
temperature of the water. Thus, it is also vital to determine the
optimum water temperature. The effect of water temperature
on the conversion of COS was investigated over the
Besides the water temperature, the effect of the feed gas
flow velocity on the conversion of COS was also investigated.
The result is shown in Fig. 7. When the flow velocity is 20
mL/min, nearly 100% COS is converted at 150 °C over
100
100
1.0 g TBAP
20 mL/min
30 mL/min
40 mL/min
80
1.8 g TBAP
80
60
40
20
0
2.8 g TBAP
60
40
20
0
20
40
60
80
100
120
140
160
Temperature (oC)
20
40
60
80
100
120
140
160
Temperature (oC)
Fig. 5. COS hydrolysis over HKUST‐1‐E25 synthesized with different
amounts of supporting electrolyte (TBAP). Reaction conditions: catalyst
mass 0.4 g, feed gas 100 mg/cm3 COS/N2, WHSV 4500 h−1, water tem‐
perature 40 °C.
Fig. 7. Influence of flow velocity on COS conversion over HKUST‐1‐E25.
Reaction conditions: catalyst mass 0.4 g, feed gas 100 mg/cm3 COS/N2,
water temperature 40 °C.

1378
Lijuan Shen et al. / Chinese Journal of Catalysis 38 (2017) 1373–1381
HKUST‐1‐E25. When the flow velocity is increased to 30
mL/min, no significant decrease of the activity is observed: the
COS conversion efficiency remains at about 98%. Further in‐
creasing the flow velocity leads to a sharp decrease in activity.
When the flow velocity is 40 mL/min, only about 50% of COS is
converted. The effect of gas flow velocity can be explained as
follows. When the flow velocity is too high, insufficient time is
available for the catalyst to fully catalyze COS hydrolysis, lead‐
ing to the decrease of the activity. Therefore, an appropriate
flow velocity is necessary for high hydrolysis efficiency of COS.
[48], and its activity and stability were tested under the same
reaction conditions as HKUST‐1. The Cu/A2O3 shows high ac‐
tivity for the hydrolysis of COS, as expected. However, as the
reaction time is prolonged, Cu/Al2O3 shows a marked decrease
in activity. After 240 min of reaction, the activity of Cu/Al2O3
declines by about 30%. These results demonstrate the ad‐
vantages of HKUST‐1 as a catalyst for COS hydrolysis.
3.9. Reaction mechanism over catalyst
To further analyze the chemical state of the constituent el‐
ements and reveal the reaction mechanism, the HKUST‐1‐E25
samples were characterized by XPS. Fig. 9(a) shows the Cu 2p
XPS spectra of HKUST‐1‐E25 before and after reaction. Two
characteristic peaks at 934.6 and 954.4 eV are observed, cor‐
responding to the Cu 2p3/2 and Cu 2p1/2 states of Cu2+, respec‐
tively. Additionally, two “shake‐up satellites” located in the
930–965 eV range are generally assigned to Cu2+, another sign
that the copper content in HKUST‐1 remains in the divalent
state, in agreement with a previous report [49]. After the reac‐
tion, no obvious change is observed in the Cu 2p XPS spectrum,
suggesting the good chemical stability of the sample in the re‐
action process. It should be noted that most copper oxides
show poor activity stability in desulfurization reactions, as the
strong affinity between copper and sulfur leads to the for‐
3.8. The stability of the catalyst
Fig. 8(a) displays the XRD patterns of HKUST‐1‐E25 before
and after the COS hydrolysis reaction. No significant difference
in the crystalline structures can be observed, indicating that the
structure of HKUST‐1‐E25 is maintained during the reaction.
Fig. 8(b) shows the stability over time of the HKUST‐1‐E25 and
HKUST‐1‐Hy catalysts. Both samples show considerable stabil‐
ity. After 240 min, about 90% and 70% conversion rates are
observed for HKUST‐1‐E25 and HKUST‐1‐Hy, respectively. The
slight decrease in the activity of HKUST‐1 can be attributed to
the formation of sulfate on the surface of the catalyst [47]. For
the sake of comparison, a Cu/Al2O3 (10/90 mass ratio) catalyst
was prepared via the incipient wetness impregnation method
Cu 2p
(a)
(a)
Cu 2p3/2
Cu 2p1/2
satellite
satellite
Used
Used
Fresh
Fresh
5
10
15
20
25
2 (o)
30
35
40
45
50
930
935
940
945
950
955
960
965
Binding energy (eV)
100
(b)
S 2p
(b)
80
60
40
20
0
HKUST-1-E25
HKUST-1-Hy
Used
Fresh
0
50
100
150
200
250
160
165
170
175
Binding energy (eV)
Time (min)
Fig. 9. Cu 2p XPS spectra (a) and S 2p XPS spectra (b) of HKUST‐1‐E25
before and after the reaction.
Fig. 8. (a) XRD patterns of fresh and used HKUST‐1‐E25; (b) COS con‐
version over HKUST‐1‐E25 and HKUST‐1‐Hy.

Lijuan Shen et al. / Chinese Journal of Catalysis 38 (2017) 1373–1381
1379
H2O
H
H
COS
H2S + CO2
O
open site
Fig. 10. Possible reaction mechanism of COS hydrolysis over HKUST‐1.
mation of CuS. The better stability of HKUST‐1 might be at‐
tributed to its unique 3D structure. In HKUST‐1, dimeric Cu
“paddle wheels” are connected to the BTC ligands to form a
complicated microporous framework. These stable structures
may have inhibited the reaction of Cu2+ with S. As a conse‐
quence, HKUST‐1 shows better sulfate resistance than typical
copper oxides. The S 2p XPS spectrum of the used sample of
HKUST‐1‐E25 shows two small peaks, at 164 and 169 eV, cor‐
responding to elemental sulfur and sulfate species, respectively
[47].
catalysts in the growing field of removing sulfur‐containing
compounds.
References
[1] B. S. Liu, X. N. Wei, Y. P. Zhan, R. Z. Chang, F. Subhan, C. T. Au, Appl.
Catal. B, 2011, 102, 27–36.
[2] B. S. Liu, Z. Y. Wan, F. Wang, Y. P. Zhan, M. Tian, A. S. C. Cheung, J.
Hazard. Mater., 2014, 267, 229–237.
[3] G. J. Ma, H. J. Yan, X. Zong, B. J. Ma, H. F. Jiang, F. Y. Wen, C. Li, Chin. J.
Catal., 2008, 29, 313–315.
A previous study using density functional theory found that
the open‐metal sites of HKUST‐1 enabled electrostatic interac‐
tion between the charge of the open metal and the multipole
moments of COS. Meanwhile, H2O binds with the open‐metal
sites via an acid–base interaction. The adsorption energy of
H2O on the Cu2+ sites of HKUST‐1 is higher than that of COS
[50]. Based on the above discussion and combined with the
previous study [11], a possible reaction pathway of COS hy‐
drolysis over HKUST‐1 can be tentatively proposed, as shown
in Fig. 10. The H2O molecules are preferentially adsorbed on
the open‐metal sites of HKUST‐1 through the strong acid‐base
interaction. Then, COS is adsorbed on the remaining
open‐metal sites through the electrostatic interaction. As the
temperature increases, the adsorbed H2O increasingly reacts
with COS, forming H2S and CO2. Although the amount of H2S
produced is small, its oxidation to sulfate is considered the
main reason for the eventual performance degradation of the
catalysts.
[4] M. Luo, X. H. Zhang, D. J. Darensbourg, Acc. Chem. Res., 2016, 49,
2209–2219.
[5] A. Ryzhikov, V. Hulea, D. Tichit, C. Leroi, D. Anglerot, B. Coq, P.
Trens, Appl. Catal. A, 2011, 397, 218–224.
[6] Y. X. Ma, X. Q. Wang, P. Ning, C. Cheng, K. Xu, F. Wang, Z. T. Bian, S.
D. Yan, Chem. Eng. J., 2016, 290, 328–334.
[7] H. B. Guo, L. H. Tang, K. Li, P. Ning, J. H. Peng, F. Lu, J. J. Gu, S. Y. Bao,
Y. Liu, T. T. Zhu, Z. Y. Duan, RSC Adv., 2015, 5, 20530–20537.
[8] Z. Q. Yi, X. M. Wang, J. Environ. Sci., 2011, 23, 784–789.
[9] C. Rhodes, S. A. Riddel, J. West, B. P. Williams, G. J. Hutchings, Catal.
Today, 2000, 59, 443–464.
[10] P. D. Clark, N. I. Dowling, M. Huang, Appl. Catal. B, 2001, 31,
107–112.
[11] P. E. Hoggan, A. Aboulayt, A. Pieplu, P. Nortier, J. C. Lavalley, J.
Catal., 1994, 149, 300–306.
[12] H. M. Huang, N. Young, B. P. Williams, S. H. Taylor, G. Hutchings,
Catal. Lett., 2006, 110, 243–246.
[13] B. Thomas, B. P. Williams, N. Young, C. Rhodes, G. J. Hutchings,
Catal. Lett., 2003, 86, 201–205.
[14] J. West, B. P. Williams, N. Young, C. Rhodes, G. J. Hutchings, Catal.
Commun., 2001, 2, 135–138.
4. Conclusions
[15] H. M. Huang, N. Young, B. P. Williams, S. H. Taylor, G. Hutchings,
Green Chem., 2008, 10, 571–577.
[16] P. Ning, L. L. Yu, H. H. Yi, X. L. Tang, H. Li, H. Y. Wang, L. N. Yang, J.
Rare Earth., 2010, 28, 205–210.
[17] J. Canivet, A. Fateeva, Y. M, Guo, B. Coasne, D. Farrusseng, Chem.
Soc. Rev., 2014, 43, 5594–5617.
[18] A. Schoedel, M. Li, D. Li, M. O’Keeffe, O. M. Yaghi, Chem. Rev., 2016,
116, 12466–12535.
[19] S. Lee, E. A. Kapustin, O. M. Yaghi, Science, 2016, 353, 808–811.
[20] X. H. Li, W. L. Guo, Z. H. Liu, R. Q. Wang, H. Liu, Appl. Surf. Sci., 2016,
369, 130–136.
[21] N. L. Rosi, J. Eckert, M. Eddaoudi, D. T. Vodak, J. Kim, M. O'Keeffe, O.
M. Yaghi, Science, 2003, 300, 1127–1129.
HKUST‐1 has been synthesized by a simple and mild elec‐
trochemical method. By controlling the synthesis voltage, the
morphology and the catalytic properties of the HKUST‐1 can be
facilely tuned. The HKUST‐1‐E25 sample shows the highest
efficiency for the hydrolysis of COS, with nearly 100% conver‐
sion at 150 °C. This is significantly higher than that of the sam‐
ple prepared by the hydrothermal method (~60% conversion),
demonstrating the benefit of synthesizing MOFs by the elec‐
trochemical method. This work is the first example of the use of
MOFs for COS hydrolysis. It is hoped that our work could not
only offer useful information on the electrochemical fabrication
of MOFs but also open a new window on the use of MOFs as
[22] Z. P. Chen, L. X. Ling, B. J. Wang, H. L. Fan, S. G. Ju, J. Mi, Appl. Surf.

1380
Lijuan Shen et al. / Chinese Journal of Catalysis 38 (2017) 1373–1381
Graphical Abstract
Chin. J. Catal., 2017, 38: 1373–1381 doi: 10.1016/S1872‐2067(17)62874‐2
Tuning the growth of Cu‐MOFs for efficient catalytic hydrolysis of
carbonyl sulfide
Lijuan Shen, Gaojie Wang, Xiaoxiao Zheng, Yanning Cao, Yufeng Guo, Ke Lin,
Lilong Jiang*
Cu2+
Fuzhou University
HKUST-1
A series of Cu‐based metal‐organic frameworks (MOFs), HKUST‐1, with
different morphologies has been controllably synthesized by a mild anod‐
ic‐dissolution electrochemical method. The obtained samples function as
novel and efficient catalysts for COS hydrolysis.
COS
H2O
H2S
CO2
Sci., 2016, 387, 483–490.
[23] Z. X. Zhao, X. L. Ma, A. Kasik, Z. Li, Y. S. Lin, Ind. Eng. Chem. Res.,
2013, 52, 1102–1108.
[24] S. S. Zhao, J. Yang, Y. Y. Liu, J. F. Ma, Inorg. Chem., 2016, 55,
2261–2273.
[25] H. Y. Li, Y. L. Wei, X. Y. Dong, S. Q. Zang, T. C. W. Mak, Chem. Mater.,
2015, 27, 1327–1331.
[26] G. Q. Song, Z. Q. Wang, L. Wang, G. R. Li, M. J. Huang, F. X. Yin, Chin.
J. Catal., 2014, 35, 185–195.
[27] P. Pachfule, D. Shinde, M. Majumder, Q. Xu, Nat. Chem., 2016, 8,
718–724.
[28] J. W. Liu, L. F. Chen, H. Cui, J. Y. Zhang, L. Zhang, C. Y. Su, Chem. Soc.
Rev., 2014, 43, 6011–6061.
[29] M. Zhao, S. Ou, C. D. Wu, Acc. Chem. Res., 2014, 47, 1199–1207.
[30] L. J. Shen, R. W. Liang, L. Wu, Chin. J. Catal., 2015, 36, 2071–2088.
[31] L. J. Shen, M. B. Luo, Y. H. Liu, R. W. Liang, F. F. Jing, L. Wu, Appl.
Catal. B, 2015, 166–167, 445–453.
[37] C. Y. Chuah, K. Goh, T. H. Bae, J. Phys. Chem. C, 2017, 121,
6748–6755.
[38] H. Al‐Kutubi, J. Gascon, E. J. R. Sudhölter, L. Rassaei, ChemElectro‐
Chem, 2015, 2, 462–474.
[39] M. Hartmann, S. Kunz, D. Himsl, O. Tangermann, S. Ernst, A.
Wagener, Langmuir, 2008, 24, 8634–8642.
[40] R. Ameloot, L. Stappers, J. Fransaer, L. Alaerts, B. F. Sels, D. E. De
Vos, Chem. Mater., 2009, 21, 2580–2582.
[41] P. Küsgens, M. Rose, I. Senkovska, H. Fröde, A. Henschel, S. Siegle,
S. Kaskel, Microporous Mesoporous Mater., 2009, 120, 325–330.
[42] A. Martinez Joaristi, J. Juan‐Alcañiz, P. Serra‐Crespo, F. Kapteijn, J.
Gascon, Cryst. Growth Des., 2012,12, 3489–3498.
[43] Y. T. Wang, Y. Y. Lu, W. W. Zhan, Z. X. Xie, Q. Kuang, L. S. Zheng, J.
Mater. Chem. A, 2015, 3, 12796–12803.
[44] C. L. Xin, H. J. Zhan, X. Huang, H. Q. Li, N. Zhao, F. K. Xiao, W. Wei, Y.
H. Sun, RSC Adv., 2015, 5, 27901–27911.
[45] P. D. C. Dietzel, R. E. Johnsen, H. Fjellvag, S. Bordiga, E. Groppo, S.
Chavan, R. Blom, Chem. Commun., 2008, 5125–5127.
[46] Y. Q. Zhang, Z. B. Xiao, J. X. Ma, Appl. Catal. B, 2004, 48, 57–63.
[47] H. Y. Wang, H. H. Yi, X. L. Tang, P. Ning, L. L. Yu, D. He, S. Z. Zhao, K.
Li, Appl. Clay Sci., 2012, 70, 8–13.
[32] M. A. Nasalevich, M. G. Goesten, T. J. Savenije, F. Kapteijn, J. Gascon,
Chem. Commun., 2013, 49, 10575–10577.
[33] L. J. Shen, R. W. Liang, M. B. Luo, F. F. Jing, L. Wu, Phys. Chem. Chem.
Phys., 2015, 17, 117–121.
[34] R. Srirambalaji, S. Hong, R. Natarajan, M. Yoon, R. Hota, Y. Kim, Y.
H. Ko, K. Kim, Chem. Commun., 2012, 48, 11650–11652.
[35] S. Marx, W. Kleist, A. Baiker, J. Catal., 2011, 281, 76–87.
[36] R. Yepez, S. Garcia, P. Schachat, M. Sanchez‐Sanchez, J. H. Gonza‐
lez‐Estefan, E. Gonzalez‐Zamora, I. A. Ibarra, J. Aguilar‐Pliego, New
J. Chem., 2015, 39, 5112–5115.
[48] A. Bansode, B. Tidona, P. R. von Rohr, A. Urakawa, Catal. Sci. Tech‐
nol., 2013, 3, 767–778.
[49] H. Chen, L. F. Wang, J. Yang, R. T. Yang, J. Phys. Chem. C, 2013, 117,
7565–7576.
[50] B. Supronowicz, A. Mavrandonakis, T. Heine, J. Phys. Chem. C,
2013, 117, 14570–14578.
Cu-MOFs的生长调控及其催化水解羰基硫的性能
沈丽娟, 王高杰, 郑笑笑, 曹彦宁, 郭玉峰, 林 科, 江莉龙*
福州大学化肥催化剂国家工程研究中心, 福建福州350002
摘要: 羰基硫(COS)广泛存在于以煤、焦炭、渣油和天然气等为原料生产的化工原料气中, 不仅腐蚀管道设备, 使下游催化
剂发生硫中毒, 而且还会造成环境污染. 因此, COS脱除具有重要意义. 在各种方法中, 催化水解COS (COS + H2O → CO2
+ H2S)由于具有反应条件温和、转化率高和副反应少等优点越来越受重视. 其关键在于发展高效的催化剂. 近年来, 金属-
有机骨架材料(metal-organic frameworks, MOFs)由于其独特的物理化学性质引起人们广泛关注. 与传统材料相比, MOFs不
仅拥有超高的比表面积和规则的孔道结构, 而且其结构具有可设计性强和易调变等特点, 是一类非常有潜力的多相催化
剂. 然而, 目前MOFs在催化水解COS方面的研究应用未见报道. 此外, MOFs的合成方法主要有水/溶剂热法、扩散法和微
波辅助加热法等. 近年来新发展的电化学法具有合成效率高、操作方便和环境友好等优点, 在材料合成中显示出巨大的优
越性, 但利用电化学法合成MOFs相关研究还较少.

Lijuan Shen et al. / Chinese Journal of Catalysis 38 (2017) 1373–1381
1381
本文采用快速温和的电化学方法制备了典型的Cu-MOFs (HKUST-1). 该方法可以有效缩短反应时间, 通过调节反应
电压(15–30 V), 在室温下电解3 h, 可得到一系列HKUST-1样品. 根据合成中设置的电压值, 样品分别命名为HKUST-1-E15,
HKUST-1-E20, HKUST-1-E25和HKUST-1-E30. XRD表征结果显示, 不同电压下合成样品的XRD谱图与通过晶体数据拟
合的HKUST-1图出峰位置基本一致. SEM结果表明, 合成电压对样品形貌的影响很大. HKUST-1-E15主要呈长棒状结构,
长约为15 μm. 随着电压的增大, HKUST-1-E20的形貌逐渐转变为较短的四棱柱体. 当电压为25 V时, 所得HKUST-1-E25
呈八面体状. 进一步提高合成电压, HKUST-1-E30颗粒变小, 没有特殊形貌, 并出现明显的团聚. COS水解测试结果显示,
不同电压下合成样品的活性差异大, 这主要是由于样品的形貌及比表面积差异引起的. 其中, HKUST-1-E25样品的活性较
好. 在150 °C下, 该样品对COS的转化率接近100%, 比水热法合成的HKUST-1-Hy的活性更高. 在此基础上, 进一步对活性
测试过程的条件进行优化, 发现当原料气流速为30 mL/min, 水温为40 °C时, 催化剂的COS水解性能最优. 此外, 样品的活
性稳定性测试结果显示, 相比传统的氧化铜材料, HKUST-1是一类较稳定的COS水解催化剂.
关键词: 金属-有机骨架材料; 羰基硫; 电化学合成; 催化水解; HKUST-1
收稿日期: 2017-04-11. 接受日期: 2017-06-17. 出版日期: 2017-08-05.
*通讯联系人. 电话: (0591)83731234; 电子信箱: jll@fzu.edu.cn
基金来源: 国家自然科学基金(21603034, 21576051); 国家高技术研究发展计划(863计划, 2015AA03A402).
本文的英文电子版由Elsevier出版社在ScienceDirect上出版(http://www.sciencedirect.com/science/journal/18722067).