Acetylene carbonylation over Ni-containing catalysts: Role of surface structure and active site distribution

Article abstract of DOI:10.1039/c6ra17567h

Heterogenization of homogeneous catalyst for acetylene carbonylation was carried out by preparing a series of Ni-modified catalysts (Ni-ZSM-5, Ni-IM-5 and Ni-MCM-41). Several important properties of the heterogeneous catalysts were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES), XPS, XRD, N₂ adsorption, pyridine-FTIR, SEM and TGA. Moreover, we used various activity criteria to dissipate perturbing factors, when we focused on the influence of surface structure and active site distribution. The result that Ni-IM-5 had the greatest TOF_Ni = 5107 g acrylic acid per g Ni per h showed that the surface structure of samples did not influence the catalyst performance significantly. In addition, the highest ratio of nickel sites/acid sites in Ni-MCM-41 represented the best active site distribution. Thus, Ni-MCM-41 has the highest TOF_cat = 70.6 g acrylic acid per g cat. per h. Furthermore, stability testing of the catalysts showed the Ni-MCM-41 could be used four times, while others only twice.

Full text of DOI:10.1039/c6ra17567h

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Page 1 of 32
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Acetylene carbonylation over NiꢀContaining Catalysts: Role of Texture
and Active Site Distribution
Hao Xie, Tiejun Lin, Li Shi, Xuan Meng∗
The State Key Laboratory of Chemical Engineering, East China University of Science and
Technology, Shanghai 200237, People’s Republic of China
Abstract
Heterogenization of homogeneous catalyst for acetylene carbonylation was
carried out by preparing a series of Ni modified catalyst (NiꢀZSMꢀ5, NiꢀIMꢀ5 and
NiꢀMCMꢀ41). Several important properties of heterogeneous catalyst were
determined by ICPꢀAES, XPS, XRD, N2 adsorption, pyridineꢀFTIR, SEM and TGA.
Moreover, we using various activity criterion to dissipate the disturbed factors, when
we focus on the influence of texture and active site distribution. The result that
NiꢀIMꢀ5 had the greatest TOFNi.=5107 g acrylic acid/ (g Ni·h), showed that the
texture of samples did not influence the catalyst performance significantly. And the
highest ratio of nickel site/acid site in NiꢀMCMꢀ41 represented the best active site
distribution. Thus, NiꢀMCMꢀ41 have the highest TOFCat.=70.6 g acrylic acid/ (g
cat.·h). Furthermore, the stability test of catalyst showed the NiꢀMCMꢀ41 could use
four times, while others only twice.
Keywords: Carbonylation, Acetylene, Molecular sieve, Acid site, Texture
∗ To whom correspondence should be addressed. Eꢀmail: mengxuan@ecust.edu.cn
Tel.: 021ꢀ64252383.

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1 Introduction
Unstable supplement and volatility price of oil, make the acetylene had received
renewed attention, recently [1]. Because of thermodynamic active state and broader
sources (like natural gas, coal or shale gas) of feedstock, acetyleneꢀbased process
become the potential route for alternating petroleum to manufacture bulk chemicals,
like acrylic acid[2ꢀ3]. Generally, nickelꢀbased catalysts, especially the Ni(CO)4 and the
nickel halide, are commonly used as active homogeneous catalysts for acetylene
carbonylation to gain acrylic acid (Scheme 1)[4ꢀ7]. According to these reports, no
matter using the toxic catalyst Ni(CO)4 or the nickel halide, the highest acrylic acid
are the same, ~70%. Otherwise, except the danger of toxicity, it is difficult to separate
the production and the homogeneous catalyst.
With respect to the green chemistry principles, heterogenization of homogeneous
catalyst for acetylene carbonylation have become one of the most attractive areas[8, 9]
The team of Bhattacharyya had investigated the reaction carried out on Ni
.
complexꢀsilica, in 1960s [6, 10ꢀ11]. However, the catalyst performance is not as good as
expectation. In their reports, the highest conversion of acetylene is just 8.56%, means
that all of these investigated heterogeneous catalyst was little active for this reaction.
Molecular sieves are one of the most commonly used heterogeneous catalysts for
many reactions[12]. Sarkar B R [13] et al use the MCMꢀ41 as the support to promote the
catalyst activity. Modified ZSMꢀ5 [14] also have been considered as an efficient
heterogeneous catalysts for the carbonylation. In general, the activity of transition
metalꢀcontaining zeolites relies on the containing of metal and on the nature of the

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zeolite with respect to the strength and concentration of acid sites, pore dimensions,
and accessibility of acid sites. Therefore, the difference in activity between different
molecular sieves should be more pronounced, especially in the condition that the
heterogeneous catalyst for acetylene carbonylation needs more fundamental research.
We have already reported catalyst NiY (prepared by ionꢀexchange) performed
better than NiOꢀY (prepared by impregnation) in acetylene carbonylation[16]. More
property of Niꢀexchanged molecular sieves, such as texture and active site, would be
investigated in this context. Nickel modified various molecular sieves (ZSMꢀ5, IMꢀ5
and MCMꢀ41) was synthesized via ionꢀexchanged. Active metal content and state
were determined by ICPꢀAES and XPS, while structural information was obtained
through XRD and N2 adsorption, and acidity property was measured by FTꢀIR using
pyridine probe. As for the surface photographs of fresh and recovered catalysts were
taken by SEM. Our attention has also focused on the reusable of catalysts.

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2. Experimental
2.1. Catalyst preparation.
The raw materials were either purchased (ZSMꢀ5, IMꢀ5) or homeꢀsynthesized
(MCMꢀ41). Zeolite NaZSMꢀ5 (SiO2/Al2O3 = 50, Nankai University catalyst Co., Ltd.)
and NaIMꢀ5 (SiO2/Al2O3 = 48, Institute of Petrochemical Research) were used as
received and in powder form. MCMꢀ41 was synthesized using the method reported by
Zhao X S [17]. A precursor gel was composed of fumed silica, sodium silicate
(Na2SiO3·9H2O), cetyltrimethyl ammonium bromide (CTAB), deionized water and
concentrated sulfuric acid (H2SO4) with the molar composition of 1.0 SiO2:0.2 CTAB:
60 H2O. The precursor solution stirred for 2 h at room temperature followed by
crystallization in a Teflonꢀlined autoclave at 120°C for 2 days under autogenous
pressure. The solids were recovered by filtration, washed with deionized water, and
dried at 120°C overnight. And heated to 550°C at a heating rate of 2°C/min and
calcined at 550°C for 6 h to remove the template.
All the parent materials were prepared by ionꢀexchanged procedure to introduce
nickel ion. For ionꢀexchanged process, 1g of molecular sieve was exchanged with 20
mL of 100 mM/L Ni(NO3)2 solution, under the condition that at 363 K and stirring for
24 h in a roundꢀbottomed flask followed by filtration, washed thoroughly using
deionized water, dried at 120°C for 12 h. Then transferred into a muffle furnace, and
calcined at 550°C for 5 h in static air atmosphere. The resulting samples denoted as
NiꢀX (X= ZSMꢀ5, IMꢀ5, MCMꢀ41).
2.2. Catalyst activity.

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The catalytic carbonylation of acetylene was carried out in a 0.5 L stainless
steelꢀ316 Parr autoclave having the gas inlet and outlet, a rupture disk for safety
measure, intermediate sampling, temperatureꢀcontrolled heating, and variable
agitation paddle. In a typical experiment, known quantities of catalyst powders (0.5 g),
promoters (0.2077 g CuBr2), H2O (15 ml), and acetone (150 mL) were added into a
stirred pressure reactor which inflate with nitrogen several times for purification and
subsequently pressurized with acetylene to 0.4 MPa and then to 4.0 MPa of initial
total pressure with CO (both controlled by mass flowmeter and the molar ratio of
CO/C2H2=1.05) at room temperature. After reaction completed at 235°C and stirring
rate was 200 rpm, the autoclave was quickly cooled to room temperature and the tail
gas and liquid were collected, calculated and analyzed. The detailed schematic
drawing of the reactor can be found elsewhere [18]. The conversion of acetylene,
selectivity and yield of acrylic acid and the turnover of frequency (TOF) are defined
as follows:
np
Yield = ×100%
(Eq. 1)
(Eq. 2)
(Eq. 3)
n0
gAA
TOF
=
×100%
Cat.
gcat ⋅h
gAA
TOFNi =
×100%
gNi ⋅h
Where,
n0, molar content of acetylene for feedstock before reaction;
np, molar content of acetylene for forming acrylic acid;
gAA, the mass of acrylic acid produced during reaction;

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gcat, the mass of catalysts for input before reaction;
gNi, the mass of nickel contained in the catalysts for input before reaction.
2.3. Characterization
The samples were previously dissolved by acid digestion followed by measured
by inductively coupled plasma atomic emission spectroscopy (ICPꢀAES, Varian
710ES). And Chemical composition in prepared catalyst was determined.
The chemical state of nickel ion on the catalyst was obtained, by XPS using a
Perkin–Elmer PHI 5000 C ESCA system equipped with Mg anode. Their binding
energies were corrected by the C 1s line at 284.6 eV.
The crystal structure of samples was characterized by Xꢀray diffractometer
(XRD, Bruker D8, Germany) equipped with an atmosphere and temperature control
stage and using Cu Kα radiation (λ= 1.5406 Å) operated at 40 kV and 100 mA. The
scanning range from 10 °to 80 ° (2θ), 0.02 step, and 1 s/step.
The texture porosity of the samples were performed using a Micromeritics ASAP
2010 nitrogen adsorption instrument. All samples were degassed under vacuum at
300°C overnight, prior to measurements. The microporous volume, mesoporous
volume and specific surface area of the catalyst were calculated using HK, BJH and
BET method.
The acidity property of the samples was determined by Fourier transform
infrared (FTꢀIR) spectroscopy (Nicolet Company, Model MagnaꢀIR550) using
pyridine as the probe. Selfꢀsupported wafers previously saturation adsorption of
pyridine at 80°C followed by cooling to ambient and under vacuum of 10−2 Pa for 90

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min. Afterwards, total acid sites (T) of sample were measured after desorption at
200°C. The pyridine adsorption, measured after desorption at 450°C, represents the
strong acid sites (S). The difference represents the weak acid sites (W).There are two
varieties of acid: one is a Brønsted acid (denoted as B), whose characteristic
absorption peak is located at 1545 cm−1; and the other is a Lewis acid (denoted as L),
located at 1450 cm−1. And Lewis and Brønsted acidic site can be calculated via the
Lambert–Beer law: A = ξ·C·d where A is absorbance, C is sample concentration, ξ is
extinction coefficient and d is sample thickness. Surface acid contents of adsorbents
for Lewis acid and Brønsted acid were calculated by using empirical formulas which
are obtained from the relevant experiments.
CL (mol·g−1) = 3.73 × 10−3 AL
CB (mol·g−1) = 9.90 × 10−3 AB
(Eq. 4)
(Eq. 5)
Where CL and CB are respectively Lewis and Brønsted acid contents (mol g−1), AL and
AB are respectively peak areas in 1450 cm−1 (denoted as L) and in 1545 cm−1 (denoted
as B) [19, 20]
The morphologies of fresh and recovered catalysts were obtained using a Nova
Nano SEM450.
.
The recovered catalysts were measured by thermoꢀgravimetric analysis (TGA).
The samples were heated up to 800°C at 10°C/min under flowing air at 100 ml/min,
recording continuously the weight of each sample.

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3. Result and discussion
3.1. Component analysis
The chemical elements of parent material and Niꢀmodified catalyst were
determined by ICPꢀAES. The Ni loading, charge balanced of Na and Ni, and the ratio
of silicon to aluminum are present in Table 1. As we can see, all the raw material has
the similar Na Content (1.5/1.4/1.9 wt. % on ZSMꢀ5, IMꢀ5 and MCMꢀ41). Otherwise,
NiꢀMCMꢀ41 has the highest Ni loading, 2.08 wt. % while the NiꢀZSMꢀ5 and NiꢀIMꢀ5
are 1.51 %, 1.27 %, respectively. Valent analysis of nickel on the reaction was
measured by XPS, and the results are presented in Fig. S1. Ni 2p3/2 region shows two
main components peak maxima with binding energies of ~856.1 and ~861.9 eV. The
appearance of these two peaks indicating the existence of divalent nickel and its
complex multiple species (not including Ni oxides), respectively [21, 22]. Oliveira et al
[23] interpreted the behavior of the Ni 2p3/2, and regarded that the characteristics peaks
at ~856.0 were assigned to Ni2+. Even though these two peaks' positions of
Niꢀmodified catalysts was little different, it could be contributed to the measured error.
Because of the same modification, including the preparation method and the treated
condition, the valence state of nickel was the same, even it supported on different
molecular sieves [24, 25]
.
3.2. Structure characterization
The XRD patterns of parent materials and the corresponding modified catalyst
are presented in Fig. S2. The patterns of the nonꢀexchanged molecular sieve
correspond well to those reported in the literatures as well as the modified samples[17,

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26]. Compared to the parent materials, there is no significant structural modification
and none of nickel oxide after nickel modified was found in the XRD patterns.
According to the literature, the metal cations introduced to the molecular sieves by
ionꢀexchange process are in the form of a skeleton balanceꢀcharge. It was means that
one Ni2+ cation exchanged into the zeolite charges compensate two change sites (Na).
Thus value of n(2Ni + Na) in catalyst should be equal to n(Al) and original n(Na),
namely their ratios should be should be a constant value (≈1.0)[20]. From the Table 1,
it is easy to conclude that the nickel cations compensated to the skeleton structure and
exist as chargeꢀcompensating as well as highly dispersed [27]. Furthermore, the color
of samples prepared via incipient wetness impregnation (IWI, 2 wt. %) is gray, which
is much more different from the white Ni exchanged catalysts (Fig. S3). In the
patterns of XPS, it is also hard to find the characteristic peaks of Ni oxides. And the
Xꢀray diffraction peaks of the modified samples were less intense, indicated the slight
decrease in the crystallinities of sample during the introduction process of metal ions
and subsequent calcination.
Textural properties of catalysts are given by N2 adsorptionꢀdesorption isotherms
and showed in Fig. 1. Due to little uptake of nitrogen, an almost horizontal isotherm
was found at the P/P0 range from 0.1 to 0.4 for Niꢀexchanged ZSMꢀ5 and IMꢀ5. It
reflected the presence of micropores[28]. When nitrogen desorbed at P/P0 higher than
0.4, hysteresis loops in the desorption branch were observed, which indicated the
presence of mesopores in NiꢀZSMꢀ5 and NiꢀIMꢀ5. The isotherm of NiꢀZSMꢀ5 and
NiꢀIMꢀ5 was type IV and type I, respectively. As for NiꢀMCMꢀ41, due to the

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characteristic capillary condensation within mesopores and multilayer adsorption on
the outer surface, it exhibits a type IV nitrogen adsorptionꢀdesorption isotherm[29, 30]
Moreover this isotherm was likely the combination of the shapes of type I and type IV
in the range P/P0 more than 0.4. It meant the NiꢀMCMꢀ41 contained the features of
mesoporous properties of the samples above.
.
Table 2 shows the calculated texture properties of different Niꢀmodified catalysts,
including specific surface area (S), micropore and mesopore volumes (Vmicro, Vmesco).
Because of the same MFI structure, NiꢀZSMꢀ5 and NiꢀIMꢀ5 have the similar specific
surface area and microporous volume. These results agree with the previously
reported data [31,32]. Significant mesoporous volumes and a high adsorption
corresponding to the presence of pores with diameters in the range of large
mesoporosity were observed in NiꢀIMꢀ5 and NiꢀMCMꢀ41(Fig. 1). Table 2 shows that
the NiꢀMCMꢀ41 has the largest specific surface area, more than 1300 m2/g, as well as
the largest mesoporous volume.
3.3. Acidity determination
In order to investigate the relationship between reaction performances and the
properties of acidic sites on the catalyst, the spectra of FTꢀIR using pyridine as the
probe molecule was obtained and shown in Fig. 3. At 200°C, the vibrations of
pyridine molecules bound at 1450 cm−1 was stronger than the peals centered at 1545
cm−1 for all the samples. It suggested that the total L acid site was more abundant than
B acid site on all Niꢀmodified samples. And all of the zeolites have the obvious
characteristic peaks at 1490 cm−1, arising due to overlaps of ν(C–C) vibration of

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pyridine adsorbed at L and B acid site. After the samples treated at 450°C, all the
peaks appeared at 200°C became almost invisible, especially for the spectrum of
NiꢀZSMꢀ5 and NiꢀIMꢀ5, meant the less strong acid site. The more detail important
features were obtained by the Equation (4) and (5), and showed in Table 3. The weak
acid site on almost all samples are dominated. Meanwhile, L acid site was richer than
B acid site, no matter weak or strong acid site. However, there was several difference
among them. L and B acid site on NiꢀZSMꢀ5 was relatively balanced, while
NiꢀMCMꢀ41 have much more L acid site than B acid site, no matter the strong or
weak acid site. As for NiꢀIMꢀ5, the amount of strong B is more than strong L acid site
and weak acid site distribution is relatively balanced.
3.2. Catalytic activity
The different Niꢀexchanged samples were tested by acetylene carbonylation. The
reaction was carried out in the autoclave at the temperature 235°C and 4 MPa of
initial total pressure for 120 min. Catalytic evaluation using parent materials (ZSMꢀ5,
IMꢀ5 and MCMꢀ41) was also performed, and no acrylic acid products were obtained
in these cases, suggesting that the acid sites alone are not able to activate the reaction
under the reaction condition. On the contrary, all the Niꢀmodified catalysts showed
good performance for the acetylene carbonylation, and released that nickel is
indispensable. Similarly, Huang et al [33] regards the nickel as the key to the
hydroesterification of acetylene with CO and methyl formate to gain methyl acrylate
carbonylation.
NiꢀMCMꢀ41 has the greatest TOFCat., 70.60 g acrylic acid/ (g cat.·h), and TOFCat

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of other two zeolites is 64.50 and 66.40 g acrylic acid/ (g cat.·h), for NiꢀZSMꢀ5 and
NiꢀIMꢀ5 respectively. The tendency of TOFCat. is the same as yield, while TOFNi had
something different. NiꢀIMꢀ5 have the highest TOFNi, followed by NiꢀZSMꢀ5 and
NiꢀMCMꢀ41. The order catalyst activity was different when using different criterion,
due to the different factors considered. If used TOFCat., we concentrated on an entire
catalyst. While TOFNi is a helpful standard to dissipate the effect of the number of the
metal site. Therefore various TOF were effective in the different situation.
The high nickelꢀcontaining NiꢀMCMꢀ41 shows the excellent yield for the
acetylene carbonylation over other Niꢀcontaining catalysts. However, Ni content in
NiꢀZSMꢀ5 is higher than NiꢀIMꢀ5, but the yield of NiꢀZSMꢀ5 is weaker than NiꢀIMꢀ5.
Thus, the amount of nickel is not the only factor influenced the reaction. In order to
explain these differences in catalytic activity, other two main categories of properties
have to be considered: the textural property and the active site distribution.
In the first case, TOFNi which assisted to observe the association between catalyst
structure and catalyst performance, was selected to present the activity. Related data
were showed in Table 2. Focus on the topology and pore architecture of the samples,
NiꢀZSMꢀ5 and NiꢀIMꢀ5 had the similar microporous texture. The difference in TOFNi
between MFI zeolites might be caused by the mesoporous structure. On the basis of
this hypothesis, NiꢀMCMꢀ41 which have the mesoporous character of both the MFI
zeolites we used, should have the highest TOFNi. However, hierarchical mesoporous
structure might not have the advantage in this reaction, according to the actual TOFNi.
For most of the reaction, when the other factors were similar, a large specific area

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means the high performance. Otherwise, NiꢀMCMꢀ41 had the largest BET area, but
the lowest TOFNi. While NiꢀIMꢀ5 had the second largest BET area, but highest TOFNi.
These results suggesting that the size of the specific area, as well as the pore volume,
did not influence the catalyst activity obviously. In a word, topology or pore
architecture did not contribute to the reaction activity significantly.
Apart from the molecular sieves structure, active site distribution is the important
factor must be concerned. Active site commonly includes the metal site and acid site
for metal modified catalyst. Many reactions need acid site to improve the catalyst
performance, such as L acid site is helpful for the hydrogenation process. It is
generally known that introduced metal into molecular sieve gave rise to new acid sites
[34]. This suggesting that metal site played the role of both active site and acid site. For
acetylene carbonylation, active intermediates generated on the acid site firstly, and
transformed to production on metal site Ni2+[16]. Thus, when considerate the influence
of the active site, nickel loading or acid property cannot be explored independently.
The ratio of metal site and acid site, presented as value R, is put forward to measure
the influence of catalytic sites distribution for reaction quantitatively. The catalyst
performance represented as TOFNi, has removed the Ni containing disturbance. In this
section, TOFCat. is used as the criterion for catalyst activity, due to the significant
influence of nickel on acid property. And the relevant data is shown in the Table 4.
Consequently, R of modified samples followed the order of NiꢀMCM41>
NiꢀIMꢀ5>NiꢀZSMꢀ5, and it met the order of catalyst activity well. Several conclusions
were pointed out. Firstly, all the R values are smaller than one, meant all the nickel

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played as both acid site and the active site and the support also provided the acid site.
Furthermore, R reflected the rich level of nickel in unit acid site. When intermediates
formed on acid site, only a metal site nearby, can the product obtained (Scheme 2).
Therefore, higher the R, better the catalyst performance.
3.2. Catalyst Stability
Reusability is crucial for heterogeneous catalysts and further applications in
industrial scale. It is available regarding the stability and recyclability of molecular
sieves catalysts in liquidꢀphase of acetylene carbonylation. Fig. 4 gives the reusability
test of Ni modified catalysts for several repeated run. All the tests were carried out at
the same initial condition for 120min, except using different kinds of catalysts. It lost
more than 50% of initial performance when used NiꢀZSMꢀ5 and NiꢀIMꢀ5 catalysts
one more time. As for NiꢀMCMꢀ41, it lost its 50% of initial activity after the third
catalytic run.
The Ni containing of used catalysts and liquid products was measured by ICP.
The leakage of Ni happened, but the amount of missing was only ~2.3%, which could
be negligible. Furthermore, nickel was hardly detected in the liquid product. Thus, the
leakage cannot be the key to the deactivated catalyst. The observation of a small
amount of black particles in the recovered catalyst, can be inferred to the coke
deposited over the external surface of zeolite. SEM results of fresh and recovered
catalyst are shown in Fig. 5. In the SEM micrograph, NiꢀZSMꢀ5 and NiꢀIMꢀ5 zeolites
(Fig. 5a, 5c) were prohibited as a long cubical shape crystal, which is similar to other
literatures[35]. Otherwise, the crystal shape of NiꢀZSMꢀ5 and NiꢀIMꢀ5 was similar, but

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NiꢀZSMꢀ5 was bigger than NiꢀIMꢀ5 in size. Fig. 5e shows the typical SEM images of
NiꢀMCMꢀ41, where crystal particles of near sphere can be consistently seen. However,
the agglomerates of small particles is easily noted. It is evident that the catalysts
retained their microstructure after reaction. Otherwise, the surfaces of all the
recovered catalyst turned rough and covered by a layer of tiny particles. The TGA of
recovered catalysts (Fig. 6) also indicated the existence of coke, which is line with the
findings in the TGꢀDTG analysis, and is agreement with the above results of
reusability test of catalyst. As the TGA of recovered catalyst showed, the weight loss
before 200°C in all of the tested samples is attribute to the vaporization moisture. In
the range from 200 to 650°C, about 10 wt. % coke was observed on the quickly
deactivated catalysts, NiꢀZSMꢀ5 and NiꢀIMꢀ5, while almost no coke on NiꢀMCMꢀ41.
It can referred that the coke may cover the active site, limit the accession of the
reactant molecules and deactivate the catalyst.

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4 Conclusion
Different Niꢀmodified catalysts were examined as a case of highly efficient
heterogeneous catalyst for the carbonylation of acetylene with carbon monoxide and
water to yield acrylic acid. A careful comparison of catalysts prepared by different
supports (ZSMꢀ5, IMꢀ5, and MCMꢀ41) reveals that the NiꢀMCMꢀ41 showed the
highest TOFCat.=70.60 g acrylic acid/ (g cat.·h) and NiꢀIMꢀ5 had the greatest
TOFNi=5108 g acrylic acid/ (g Ni·h).
Characterization of ICPꢀAES, XPS, and XRD indicates the introduced nickel
existed as Ni2+, and compensated for the skeleton structure. All the modified catalyst
maintain their original structure. Activity criterion TOFCat showed the structure of the
molecular sieve did not contribute to activity obviously. It is found that the balance
between acid site and nickel site, played a significant role in determining their activity
by TOFCat.. The highest Ni2+/Acid sites ratio indicates the Ni and acidic functions
were well balanced and performed in the acetylene carbonylation best. Reusability
test of Niꢀmodified catalysts exhibited that the mesoporous martials NiꢀMCMꢀ41 has
the best anti coke deposition and multiꢀused property.

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5 Acknowledgements
We are grateful for financial support from Young Scientific Talents Sail Plan of
Shanghai City [15YF1403000] and Special Fund of Fundamental Research and
Exploration [22A201514014].

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Table 1 Elemental analysis of raw materials and nickel modified various molecular sieves
Raw
Modified
Charged Balanced Calculation
Samples
a
b
NaR
SiO2/Al2O3
Ni
NaM
Al
Cation/NaR
1.00
Cation/Al
NiZSMꢀ5
NiIMꢀ5
NiMCMꢀ41
1.46
1.38
1.93
43
45
/
1.51 0.27 1.71
1.29 0.41 1.65
2.08 0.30
0.98
1.01
/
1.02
/
1.00
a, NaR, means the content of Na in the raw materials
b, NaM, means the content of Na in the modified catalyst
c, means calculated assuming that every positive charge from the exchanged cations can
charge compensate an exchange site, Cation=Na + 2Ni.

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Table 2 Texture and activity properties of different Ni-modified catalysts
S
Vmicro
Vmesco
TOFNi
gAA/gNi·h
Catalyst
(m2/g)
(cm3/g)
(cm3/g)
NiꢀZSMꢀ5
NiꢀIMꢀ5
230.54
267.29
1312.86
0.117
0.136
/
0.054
0.499
1.033
4300
5108
3362
NiꢀMCMꢀ41

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Table 3. Acidic properties of different Ni-modified catalysts (m mol/g).
Catalysts
NiꢀZSMꢀ5
NiꢀIMꢀ5
T
TB
TL
SB
SL
WB
11.23
6.77
1.13
WL
24.30 11.97
11.33
10.44
7.40
0.74
0.29
0.35
0.98
0.02
1.56
11.35
10.42
5.84
17.50
7.06
1.48
NiꢀMCMꢀ41 8.88
T—Total acid; TL—total Lewis acid; TB—total Brønsted acid; SL—strong Lewis acid;
SB—strong Brønsted acid; WL—weak Lewis acid; WB—weak Brønsted acid.

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Table 4 Catalytic behavior of different Ni-modified catalysts for acetylene carbonylation
Ni2+
Acid
R(Ni2+/Acid)
mol/ mol
TOFCat.
Catalyst
wt,%
m mol/g
24.30
17.50
8.88
gAA/gcat.·h
NIZSMꢀ5
NiIMꢀ5
1.5
1.3
2.1
0.011
0.013
0.040
64.5
66.4
70.6
NiMCMꢀ41

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Scheme 1. Carbonylation of acetylene with CO and water to yield acrylic acid.

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Scheme 2. Active site on the Ni-modified catalyst surface

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Fig. 1. Nitrogen adsorption–desorption isotherms of different Ni-modified catalysts

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Fig. 2. The yield and TOF of the different Ni-modified catalysts

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Fig. 3 Pyridine-FTIR spectra of the Ni-modified catalyst at 200°C and 450°C