Engineering Porphyrin Metal-Organic Framework Composites as Multifunctional Platforms for CO2Adsorption and Activation

Article abstract of DOI:10.1021/jacs.0c05909

As an effective solution toward the establishment of a sustainable society, the reductive transformation of CO2 into value-added products is certainly important and imperative. Herein, we report a porphyrin metal-organic framework composite Au@Ir-PCN-222, which is obtained through the in situ formation of Au nanoparticles in the coordination interspaces of Ir-PCN-222. Catalytic results show that Au@Ir-PCN-222 is highly efficient for CO2 reduction and aminolysis, giving rise to formamides in high yields and selectivities under room temperature and atmospheric pressure. Mechanistic studies disclose that the high efficiency of Au@Ir-PCN-222 is due to the synergistic catalysis of Au NPs and Ir-PCN-222, in which Au NPs can adsorb CO2 molecules on their surfaces and then increase the CO2 concentration in the cavities of the framework, and at the same time, Au NPs transfer electrons to Ir-porphyrin units and therefore increase the interactions with CO2 molecules.

Full text of DOI:10.1021/jacs.0c05909

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Article
Engineering Porphyrin Metal–Organic Framework Composites
as Multifunctional Platforms for CO2 Adsorption and Activation
Jiewei Liu, Yan-Zhong Fan, Kun Zhang, Li Zhang, and Cheng-Yong Su
J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.0c05909 • Publication Date (Web): 25 Jul 2020
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Engineering Porphyrin Metal–Organic Framework Composites as
Multifunctional Platforms for CO2 Adsorption and Activation
Jiewei Liu+a,b,d, Yan-Zhong Fan+c, Kun Zhanga, Li Zhang*c, Cheng-Yong Su*c
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aSchool of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, P.R. China.
bInternational Healthcare Innovation Institute (Jiangmen), Jiangmen 529040, P. R. China.
cMOE Laboratory of Bioinorganic and Synthetic Chemistry, Lehn Institute of Functional Materials, School of Chemistry,
Sun Yat-Sen University, Guangzhou 510275, China.
dSchool of Chemical Engineering and Light Industry, Guangdong University of Technology, Guagnzhou 510006, P. R.
China
ABSTRACT: As an effective solution towards the establishment of a sustainable society, the reductive transformation of CO2 into
value-added products is certainly important and imperative. Herein, we report that a porphyrin metal-organic framework composite
Au@Ir-PCN-222, which is obtained through the in situ formation of Au nanoparticles in the coordination interspaces of Ir-PCN-222.
Catalytic results show that Au@Ir-PCN-222 is highly efficient for CO2 reduction and aminolysis, giving rise to formamides in high
yields and selectivities under room temperature and atmospheric pressure. Mechanistic studies disclose that the high efficiency of
Au@Ir-PCN-222 is due to the synergistic catalysis of Au NPs and Ir-PCN-222, in which Au NPs can adsorb CO2 molecules on their
surfaces and then increase the CO2 concentration in the cavities of the framework, and at the same time, Au NPs transfer electrons to
Ir-porphyrin units and therefore increase the interactions with CO2 molecules.
performances towards CO2 hydrosilylation are rarely studied
1. INTRODUCTION
yet.18,19 The plentiful reticular chemistry of MOF structures
offers opportunities for the rational design of MOF composites,
which integrate CO2 adsorption and activation.20-22 Firstly, the
non-bonded interactions between CO2 and the open metal sites
or heteroatoms in the catalytic coordination spaces of MOFs
help increase the local CO2 coverage nearby the active sites.23
The cavities of MOFs can be further used for the immobilization
of co-catalysts, especially metal nanoparticles (MNPs), which
can adsorb CO2 molecules (Figure S1).24,25 Secondly, the
homogeneous catalysts as the ligands can be incorporated into
the frameworks and dispersed uniformly within the MOFs,
giving rise to heterogeneous single-site catalysts.26,27 Moreover,
the charge-transfer interaction between the electron-rich MNPs
and MOFs becomes a critical factor for controlling the catalytic
reactivity of the resultant M@MOF composites,28-31 which
could increase the electron density of the MOF, and thereafter
enhance its interactions with CO2 via the back bonding, that is,
the electron transfers from the occupied d orbitals of the metal
to the LUMO of CO2.32,33 Thirdly, the definite and uniform
structures of MOFs will benefit the study of the interactions
between CO2 and frameworks at a molecular level, which is
critical for the design of more powerful catalysts.34-36
With the continuous consumption of fossil energy by human
activities, the emission of the greenhouse gas carbon dioxide
(CO2) caused a series of environmental problems such as global
warming and the acidification of oceans. The report of the
International Energy Agency suggested that the average
concentration of CO2 was 400 ppm in 2018, and predicted that
CO2 concentration might reach 950 ppm by 2100.1 As an
effective solution towards the establishment of a sustainable
society, the reductive transformation of CO2 into value-added
products is certainly important and imperative.2-4 Among the
CO2 reduction reactions, the synthesis of formic acid by
hydrogenation of CO2 with hydrogen (H2) has attracted much
interests, but this is a thermodynamically unfavourable reaction
(G = +33 kJ·mol-1) and requires high CO2 and H2 pressures
and elevated temperatures.5 In contrast, CO2 reduction in the
presence of silanes as the reductants, which is also termed as
CO2 hydrosilylation, is a thermodynamically favored chemical
process (G = -29.3 kJ·mol-1), due to the cleavage of weaker
SiH bonds and the formation of stronger SiO bonds.6
Remarkably, silyl formates, which are formed from CO2
hydrosilylation, are of great interest due to their potential
application as synthons for the preparation of a wide range of
valuable chemicals such as formic acid, formamides and
formates with the addition of water, amines and alcohols,
respectively.7
In this paper, we report the preparation of a series of
porphyrin metal-organic frameworks M-PCN-222 (which are
also denoted as M-PMOF-2) through the self-assembly of ZrCl4
and M-TCPP (M = Ru, Rh, Pd, Ir, Pt; TCPP = tetrakis(4-
carboxyphenyl)porphyrin)).37-41 The MOFs possess a csq
topology as in PCN-22242, MOF-54543 or MMPF-644, and
contain hexagonal and triangular channels with the diameters of
3.7 and 1.3 nm, respectively. The micro cavities are used for
CO2 reservoirs whereas the meso cavities are used for the
immobilization of metal nanoparticles (M´NPs) such as Pd, Ir,
Pt and Au.45-47The resultant M´@M-PCN-222 can be
A few homogeneous reaction systems using transition metal
complexes8-13 or organocatalysts14-17 have been reported for CO2
hydrosilylation under mild conditions (RT and 1 atm) and with
high selectivities. As an emerging class of porous materials,
metal-organic
heterogeneous
frameworks
candidates,
(MOFs)
although
are
their
promising
catalytic
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functionalized as a multifunctional platform, integrating CO2 red needle-like crystals via centrifugation at 12000 rpm for 2
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adsorption and activation. Catalytic results and mechanistic
studies show that, due to the synergistic catalysis of Au NPs and
Ir-PCN-222, in which Au NPs can adsorb CO2 molecules on
their surfaces and then increase the CO2 concentration in the
cavities of the framework, and at the same time, Au NPs transfer
electrons to Ir-porphyrin units and therefore increase the
interactions with CO2 molecules, Au@Ir-PCN-222 is highly
efficient for CO2 reduction and aminolysis, giving rise to
formamides in excellent yields and selectivities under room
temperature and atmospheric pressure (Figure 1).
min, washed with ethanol for several times, and dried under
vacuum at 120 °C overnight.
2.3 Catalytic reaction
Typically, a mixture of phenylsilane (PhSiH3, 216 mg, 2
mmol), N-methylaniline (1a, 107.0 mg, 1 mmol), cesium
carbonate (Cs2CO3, 6.5 mg, 0.02 mmol) and activated Au@Ir-
PCN-222 (10 mg, 0.008 mmol) is stirred in THF (2 mL) under
atmospheric CO2 at room temperature. After 2 h, the reaction
mixture is centrifuged. The recycled catalyst is washed with
DCM (5 mL  4), dried in the air and reused in the consecutive
runs. The combined supernatant is evaporated to dryness, which
is purified by flash chromatography to afford the pure product
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N-methyl-N-phenylformamide (2a, 117 mg, 87% yield). H
NMR (400 MHz, CDCl3) of 2a: δ 8.44 (s, 1H), 7.37 (m, 2H),
7.24 (m, 1H), 7.15 (m, 2H), 3.28 (s, 3H).
2.4 Computational details
2.4.1 The molecular model of Ir-PCN-222
The periodic crystal structure of Ir-PCN-222 for calculation
is based on the reported Fe-PCN-22242 and is relaxed by
geometry optimization on the package of CP2K 2.6.1.48 The
calculation employs the Perdew-Burke-Ernzerhof functional
(GGA-PBE)49 while the Kohn-Sham orbitals for all atoms are
expanded into an atom-centered double-ζ quality DZVP-
MOLOPT-GTH Gaussian basis set.50 The pseudopotentials
used for all of the atoms are those derived by Goedecker, Teter
and Hutter.51 The cutoff energy of 650 Ry and the cutoff in
reciprocal space of 80 are considered, respectively.
Based on the crystal structure of Ir-PCN-222, the molecular
models of Ir(TMCPP)Cl (TMCPP = 5,10,15,20-tetrakis(4-
methoxycarbonylphenyl)porphyrin) and Zr6O8 clusters are
further calculated by the package of Gaussian 09.52 By ChelpG
method,53 Minnesota functional M06L54 that can perform quite
well in transit-metal system is applied to fit their electrostatic
potential (ESP) charges with a hybrid basis set of split valence
6-311G**55 for C, H, N and O while Stuttgart and Dresden
(SDD) pseudopotentials56 for Ir, Zr and Cl. In these calculations,
the atomic van der Waals radii for all atoms of the Ir-PCN-222,
which are used to fit the ESP charges, are taken from the work
of Batsanov.57
Figure 1. CO2 adsorption, diffusion and activation in the inner cavities of
Au@Ir-PCN-222.
2. EXPERIMENTAL SECTION
2.1 Synthesis of Ir-PCN-222
2.4.2 The surface model of Au@Ir-PCN-222
After a mixture of Ir(TCPP)Cl (10 mg, 0.01 mmol),
ZrOCl2·8H2O (20 mg, 0.06 mmol), trifluoroacetic acid (300 μL)
and H2O (100 μL) in N,N-dimethylformamide (2 mL) is heated
at 130 °C for 6 h, red needle-like crystals (10.9 mg, 60% yield)
are obtained and dried under vacuum at 120 C overnight for
further characterizations and uses. Anal. Calcd. for
C48H32IrClN4O16Zr3·3DMF·10H2O (C57H73IrClN7O29Zr3): C,
37.58; H, 3.04; N, 5.38%. Found: C, 37.12; H, 3.74; N, 5.82%.
FT-IR (KBr) ν 3257 (br), 2858 (br), 1587 (s), 1541 (s), 1371 (s),
1067 (s), 1010 (s), 906 (m) cm-1.
After cleaving the (100) plane of crystal, a vacuum slab of 20
Å is stacked to build the surface model. Based on Garzón’s
work, one Au38 nanocluster that is confirmed as one of the
lowest energy structures, is created near the coordinated water
molecules of Zr6O8 clusters.58 All the calculation for density of
states (DOS) is carried on the package of CP2K 2.6.1 at the near
level for geometry optimization.48 To describe the function of
Au38 nanocluster in CO2 activation, the revised PBE functional
(revPBE), which is constructed by optimizing parameters of
PBE against the exchange energy, is used to compute the
surface model without nanocluster to illustrate the impact
between adatoms and channel-wall atoms for comparison.59
2.2 Synthesis of Au@Ir-PCN-222
The suspension of the activated Ir-PCN-222 sample (20 mg)
in dry n-hexane (5 mL) is sonicated for around 5 min until it
becomes homogeneous. And then, the HAuCl4 aqueous solution
(20 mg·mL-1, 100 μL) is added dropwise with constant vigorous
stirring. The resultant solution is stirred for 2 h, and then the
reaction mixture is centrifuged to remove the supernatant. To
the harvested sample is added ascorbic acid solution (6 mg·mL-1,
5 mL). After being stirred for 2 h, the product is separated as
2.4.3 CO2 adsorption sites of Ir-PCN-222
The interactions between the Ir-PCN-222 frameworks and
the CO2 were modelled using the sum of a 12-6 Lennard-Jones
(LJ) contribution and a Coulombic term. The Universal Force
Field (UFF)60 and DREIDING61 force fields are adopted to
describe the LJ parameters for the atom of the inorganic nodes
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and organic linkers of the MOFs respectively. In this work, the
parameters of CO2 molecule are described by Elementary
physical model 2 (EPM2).62
TCPP.42 The morphology of Ir-PCN-222 is revealed by
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scanning electron microscopy (SEM) and transmission electron
microscopy (TEM), indicating that the as-prepared Ir-PCN-222
samples are in three-dimensional, rod-shaped structures with
about 600 nm width and 3 µm length (Figure 2a and 2b).
A 1×1×2 supercell for Ir-PCN-222 is considered with cell
parameters that exceed 24 Å in order to be able to apply a cutoff
radius of 12 Å for the short-range dispersion. The long-range
electrostatic interactions are handled using the Ewald
summation technique. The fugacities for CO2 at a given
thermodynamic condition are computed with the Peng-
Robinson equation of state (EoS).63 The Grand Canonical
Monte Carlo (GCMC) simulations are performed using the
Complex Adsorption and Diffusion Simulation Suite (CADSS)
code.64 For each fugacity point, the system is sustained under
2×108 equilibrium steps and 1×108 product steps under a
constant temperature 273 K. The configuration of adsorbate is
calculated through GCMC simulations using the revised
Widom’s test particle insertion method.65
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2.4.4 CO2 diffusion in Ir-PCN-222
Molecular dynamics (MD) simulations are carried out by
Lammps package66 to illustrate the transport diffusivity of CO2
in Ir-PCN-222. The structure with saturated adsorption is
obtained from the snapshot of the GCMC simulation.
Considering that total energy of the system keeps constant in
the process of diffusion, the simulation is performed in
microcanonical ensemble (NVE) at 273.15 K with the timestep
as 1 fs. For fluid simulation, Langevin equation67,68 is used to
control the kinetic energy of rigid bodies system, of which the
temperature is relaxed in 1 ps. The structure optimized with
forcefield is first equilibrated with the time of 10 ns, followed
by 50 ns production MD. The same parameters and cutoff radius
of van der Waals and long-range Coulombic potential from
GCMC simulation are employed to represent non-bonded
interaction. Considering the rigidness of Ir-PCN-222, only the
movements of CO2 are taken into consideration to simulate the
process of diffusion. The bonded forcefield parameters for CO2
are consulted from Myshakin’s work.69
Figure 2. SEM (a) and TEM (b) images of Ir-PCN-222, and median-
magnification TEM (c), high-magnification TEM (insert c) and aberration-
corrected
HAADF-STEM
(d)
images
of
Au@Ir-PCN-222.
The self-diffusivity Ds is obtained from mean squared
displacement (MSD) by Einstein equation,70
푁
1
푑
퐷푠 =
lim
2푑푁푡→∞ 푑푡
|푟푖(푡) ― 푟푖(0)|2
∑
〈
〉
푖 = 1
푟 (푡)
where
denotes as position of the adsorbate molecule i at
푖
time t, d and N represents the dimension of the system and the
number of diffusing molecules in the system under ensemble
average.
2.4.5 Reaction kinetics of CO2 hydrosilylation
The transit state search is carried on Gaussian 0952 package
with the same functional mentioned previously. Split valence
basis set 6-311G**55 is employed to describe C, H, N and O,
while Def2SVP for Ir, Cl, Au and Si.71,72
Figure 3. TEM-EDX elemental mapping images of Au@Ir-PCN-222
corresponding to Au, C, N, Ir, O and Zr elements, respectively.
The MOF composite Au@Ir-PCN-222 is prepared by the in
situ formation of Au NPs in Ir-PCN-222, which is achieved by
using a double-solvent approach (DSA). The PXRD pattern of
Au@Ir-PCN-222 is well matched with that of the pristine Ir-
PCN-222, indicating that the framework and crystallinity of Ir-
PCN-222 remain well after the introduction of Au NPs (Figure
S2). The presence of Au NPs in Au@Ir-PCN-222 is clearly
observed in the TEM images, which is marked with the red
circles in Figure 2c and the inset. The Au NPs with a width of
around 3 nm display consistent orientation (Figure 2d),
indicative of the confined growth of Au NPs starting from the
3. RESULTS AND DISCUSSION
3.1 Syntheses and characterizations
Ir-PCN-222 is prepared through the assembly of ZrCl4 and
Ir(TCPP)Cl in the presence of trifluoroacetic acid as a
modulating reagent at 130 ºC for 6 h. Powder X-ray diffraction
(PXRD) patterns confirm the bulk purity of the as-prepared
samples (Figure S2), which fit well with the simulated patterns
of PCN-222 that is constructed with metal free porphyrin ligand
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single crystal, nanocube to nanobar with a length range of 20- simulation (Figure 5 and Table S2). The results unveil that, in
60 nm in the hexagonal mesochannels (Figures S3 and S4).73
The existence of the consistent orientation growth of Au NPs in
Ir-PCN-222 is also evidenced by the high-angle annular dark-
field scanning TEM (HAADF-STEM) tomogram analysis
(Figure 2d). Meanwhile, the TEM-EDX (energy dispersive X-
ray spectroscopy) elemental mapping images demonstrate the
uniform distribution of all of the elements in the whole Au@Ir-
PCN-222 (Figure 3). The weight loading of Au NPs is
determined to be 2% using an inductively coupled plasma mass
spectrometry (ICP-MS).
the mesopores, the potential CO2 adsorption sites are mainly
near the coordinated water of Zr6O8 clusters (site 1), and some
others lay behind the Ir-Cl paralleled with porphyrin. As for site
1, the electrostatic potential (ESP) charge of the Zr element is
+1.9930 |e| (Figure S16), which might interact with the
nucleophilic O atoms in CO2, but the van der Waals interactions
from the coordinated water keep a distance between Zr6O8
clusters and free CO2 molecules. On the other hand, in the
micropores, CO2 molecules mainly interact through their ESP
charges on C atoms with the axial Cl atoms (dC-Cl = 3.2-3.3 Å,
site 2). Radial distribution function (RDF) is further applied to
investigate the specific distance in cavity (Figure S17), and the
results show that site 1 and site 2 are validated in the peaks of
O(H2O)-CO2 (dC-O = 3.8 Å) and Ir-CO2 (dC-Cl = 3.5 Å),
respectively.
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The permanent porosity of Ir-PCN-222 and Au@Ir-PCN-222
has been confirmed by N2 adsorption isotherms at 77 K, and the
Brunauer-Emmett-Teller (BET) surface areas are calculated to
be 2387 and 1452 m2·g-1, respectively (Figure S5). The pore size
distribution of Ir-PCN-222 that is calculated using the density
function theory (DFT) simulation discloses that there are two
types of pores, with the sizes of 1.2 and 3.4 nm, respectively
(Figure S6), which is well matched to the crystal structure of
PCN-222 when van der Waals interaction is considered.
X-ray photoelectron spectroscopy (XPS) examination is used
to confirm the existence and oxidation state of Ir in Ir-PCN-222
(Figure S7). The +3 valance state of Ir is clearly evidenced by
the binding energies at 62.6 and 65.6 eV, assignable to the 4f7/2
and 4f5/2 levels of Ir(III), respectively. After the incorporation of
Au NPs into the pores of Ir-PCN-222, the Au XPS spectrum of
resultant composites presents two peaks with binding energies
of 84.3 and 87.8 eV, corresponding to Au0 4f7/2 and Au0 4f5/2,
respectively (Figure S8). It is noted that Ir 4f binding energies
of Au@Ir-PCN-222 (4f7/2, 62.4 eV and 4f5/2, 65.3 eV) are
slightly shifted toward lower oxidation states than those of Ir-
PCN-222, suggesting that the charge-transfer interactions exist
between Au NPs and Ir-PCN-222 (Figure S9).28-31
Figure 4. The CO2 adsorption-desorption isotherms of Ir-PCN-222 and
The calculations for density of states (DOS) have been carried
out on the package of CP2K 2.6.1 at the near level for geometry
optimization.48 Based on Garzón’s work, one Au38 nanocluster
that is confirmed as one of the lowest energy structures, is
created near the coordinated water molecules of Zr6O8 clusters
(Figure S10).58 The O partial DOS of surface model
with/without Au38 nanocluster are shown in Figure S11. As a
metal cluster, the inclusion of the guest Au38 increases Fermi
energy by 0.40 eV and metallizes the host Ir-PCN-222, which
is consistent with the XPS experimental analysis.
Au@Ir-PCN-222.
3.2 CO2 adsorption and diffusion
The adsorption behaviors of Ir-PCN-222 and Au@Ir-PCN-
222 towards CO2 are evaluated (Figure 4 and Table S1). The
CO2 adsorption isotherms at different temperatures (e.g. 298
and 308 K) are carried out and disclose that both Ir-PCN-222
and Au@Ir-PCN-222 show high adsorption capability of CO2 at
1 bar, whereas Au@Ir-PCN-222 displays higher adsorption
performances due to the adsorption of CO2 on the surfaces of
Au NPs.25 The isosteric heats of adsorption (Qst) are calculated
from the CO2 sorption data by the virial fitting method (Figures
S12-15).74 The initial Qst of Ir-PCN-222 and Au@Ir-PCN-222
are up to 26.9 and 29.0 kJmol-1, respectively, indicative of
specific CO2 adsorption sites embedded in the pore walls. The
higher initial Qst value of Au@Ir-PCN-222 than Ir-PCN-222
further shows that, with the incorporation of Au NPs into the
inner cavities of Ir-PCN-222, the resultant composite Au@Ir-
PCN-222 shows stronger interaction with the CO2 molecules.
Figure 5. Snapshot of CO2 molecules adsorbed in Ir-PCN-222 from the
simulation (a) and the preferred CO2 adsorption site 1 (b) and site 2 (c) from
GCMC simulation. The specific conformations in the snapshot are marked
with the distance.
The snapshot of CO2 adsorbed in Ir-PCN-222 is obtained
from the results of the Grand Canonical Monte Carlo (GCMC)
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These experimental and simulation results disclose the CO2-
mesopores is consistent with the goal to use mircopores as CO2
reservoirs, which is beneficial for catalytic reactions to be
carried out in the mesopores of Ir-PCN-222.
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framework interactions, the potentials of the inner cavities of Ir-
PCN-222 as CO2 reservoirs, and the possible active sites for
CO2 activation. Based on these results, it may be concluded that
the trigonal channels are favorable for CO2 adsorption and
meanwhile the hexagonal channels become the platform for
CO2 activation. To testify this hypothesis, the potential barriers
are calculated by displacing a single molecule of CO2 along the
direction from micropore to mesopore between the neighboring
porphyrin structures (Figure 6). It can be concluded from the
results that the diffusion process from two scales of pores is
reversible with 5 kJ·mol-1 as potential barriers.
3.3 Catalysis and reaction mechanism
The catalytic performances of PMOFs and PMOF composites
towards CO2 reduction and aminolysis are studied under
atmospheric pressure and ambient temperature (Table 1). Ir-
PCN-222 is efficient for the reaction, giving rise to formamide
(2a, C+II species) and N,N-dimethylaniline (3a, C-II species) in
the yield of 89% and a selectivity of 98:2 (entry 1). For
comparison, the PMOFs based on the other two d6 metal
porphyrins such as Rh-PCN-222 and Ru-PCN-222 display
much poorer performances and give rise to low to modest yields
(entries 2 and 3). Neither Pd-PCN-222 nor Pt-PCN-222 can
promote the reaction (entries 4 and 5). Controlled experiments
further show that PCN-222 with no metal in the porphyrin can’t
work at all (entry 6). There isn’t any background reaction in the
absence of any catalyst (entry 7). It is clear that the
incorporation of Ir into the porphyrin macrocycle plays an
important role on the catalytic performances of PMOFs.
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Table 1. Catalyst screening.a
Ent
ry
Catalyst
Reaction
Time (h)
Yield
(%)b
Molar ratio
(2a:3a)
TON
TOF
(h-1)
1
Ir-PCN-222
Rh-PCN-222
Ru-PCN-222
Pd-PCN-222
Pt-PCN-222
PCN-222
24
24
24
24
24
24
24
2
89
42
11
0
98:2
98:2
87:13
/
109
51
12
/
4.5
2.1
0.5
/
2
3
4
5
0
/
/
/
6
0
/
/
/
7
none
0
/
/
/
Figure 6. Potential energy distributions for one CO2 molecule along the
direction of micropore  mesopore  micropore.
8
Ir@Ir-PCN-222
Pd@Ir-PCN-222
Pt@Ir-PCN-222
Au@Ir-PCN-222
Au NPs
81
79
75
90
0
93:7
87:13
67:33
91:9
/
94
86
63
102
/
47
43
31.5
51.1
/
9
2
To illustrate the possibility from a more direct parameter,
molecular dynamics (MD) simulations are carried out to
illustrate the transport diffusivity of CO2 in Ir-PCN-222. Based
on the trajectories recorded during MD runs, the average
residence times inside the mesopores (tmeso) and micropores
(tmicro) are calculated to be 18.22 and 20.00 ns, respectively.
When the CO2 molecules in the mesopores are exhausted with
the reaction going on, the interchange of adsorbate between two
scales of pores could occur due to a dynamic state of
equilibrium. Meanwhile, the CO2 diffusion process from
micropores to mesopores is recorded in the movie (Supporting
Information), which can vividly display CO2 transportation in
Ir-PCN-222. In order to illustrate the influence of CO2
concentration on diffusion, the diffusivities at different loading
are obtained from four trajectories (Figure S18). The
diffusivities (3.6 × 10-11 m2/s) of CO2 in Ir-PCN-222 (38 CO2
per unit cell) are rather lower compared to other MOFs,75,76
indicative of the relatively strong non-bonded interactions
between CO2 molecules and Ir-PCN-222 (Table S3). The
decreased speed of CO2 transferring from mircopores to
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13
2
2
24
2
Ir-PCN-222
+Au NPs
47
92:8
54
27
aReaction condition: CO2 (1 atm), N-methylaniline (1a, 1 mmol, 107 mg),
PhSiH3 (2 mmol, 216 mg), catalyst (0.8 mol%), Cs2CO3 (0.018 mmol, 6 mg),
THF (2 mL), 60 ºC, 24 h. bThe yield is the conversion of 1a to 2a and 3a,
which is determined by 1H NMR using 1,3,5-trimethoxybenzene as an
internal standard.
To our delight, after the immobilization of noble metal NPs
into the hexagonal mesochannels of Ir-PCN-222, the resultant
PMOF composites M´@Ir-PCN-222 (M´ = Ir, Pd, Pt, Au)
display enhanced catalytic efficiencies (entries 8-11). Among
them, Au@Ir-PCN-222 is the most efficient. MNPs in the
M@Ir-PCN-222 composites can adsorb CO2 molecules on their
surfaces and then increase the CO2 concentration in the cavities
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of the framework. At the same time, MNPs transfer electrons
Page 6 of 10
1
2
3
4
5
6
7
8
to Ir-porphyrin units and therefore increase the interactions with
CO2 molecules. As for the electron transfer from MNPs to Ir-
PCN-222, there is difference among different MNPs due to the
orbital occupation.77 The stable electron structures of an atom
are those with its atomic orbital fully filled (d10), half-filled (d5),
or empty(d0). Ir-PCN-222 is difficult to obtain electrons from
Pd0 (4d10) or Pt0 (5d10) NPs because these metals are stable with
their fully filled electron states. Besides, Ir0 (5d9) is inclined to
obtain an electron to form 5d10 while reluctant to donate it any
more. By contrast, Au0 (5d106s1) is ready to donate one electron
to form 5d10, which might explain Au@Ir-PCN-222 displays the
highest reaction efficiency among M@Ir-PCN-222 composites
(M = Ir, Pd, Pt, Au).
Recycling experiments have been studied to show the
robustness of Au@Ir-PCN-222 as a heterogeneous catalyst. The
results show that no significant activity loss occurs during four
successive runs (Figure S19). The TEM image of the recycled
Au@Ir-PCN-222 indicates that it almost maintains its
morphology (Figure S20). The PXRD of the recycled samples
further confirm that the crystallinity of Au@Ir-PCN-222
remains intact after the catalytic reactions (Figures S21). The
XPS spectrum of the recycled Au@Ir-PCN-222 sample after the
catalytic reaction shows that the +3 valance state of Ir remains.
As shown in Figure S22, the peaks with the binding energies at
62.4 and 65.3 eV are assignable to the 4f7/2 and 4f5/2 levels of
Ir(III), respectively. ICP-MS analysis of the filtrate after
catalysis discloses that the amount of Au leaching into the
reaction mixture is around 0.21%.
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To explore the effect of Au NPs, the polyvinyl pyrrolidone
(PVP) stabilized Au NPs are prepared and applied in the same
reaction. It is found that no reaction occurs at all when Au NPs
are used as the sole catalyst (entry 12). The results disclose that
Ir-PCN-222 instead of Au NPs is the catalytically active sites
within Au@Ir-PCN-222, but nevertheless, the synergistic
catalysis of these two components largely increases the reaction
efficiency. In addition, the simple mixture of Au NPs and Ir-
PCN-222 can only induce a modest yield of 54% in 2 h (entry
13).
The hydrosilylation of CO2 might occur through either an
outer-sphere or inner-sphere pathway (Figure 7).2,4 As for the
outer sphere pathway, the CO2 hydrosilylation process is
initiated by phenylsilane coordination to the iridium center via
a η2-(Si–H) mode, and ends with transfer of silyl and hydride
ligands to CO2 in a concerted way. For comparison, in the inner
sphere pathway, the iridium center firstly interacts with the CO2
molecule in the side-on (η2-C,O) coordination, and then the
coordinated CO2 reacts with phenylsilane in the similar
concerted way as the outer sphere pathway. Both pathways lead
to the formation of the silyl formate as the intermediate, which
then react with amines (1) to generate the final products of
formamides (2).
The substrate scope regarding to amines is studied using Ir-
PCN-222 as the catalyst (Table 2). It is found that a series of
para-substituted N-alkylanilines perform smoothly to give the
corresponding formamides (2a-e) with the yield range of 77-
87%. Indoline and 1,2,3,4-tetrahydroquinoline can react with
CO2 in the presence of PhSiH3 as the reducing regent, and the
formamides 2f and 2g are produced in 95 and 75% yields,
respectively. The primary amine aniline can be also involved in
the catalytic reaction, producing N-phenylformamide (2h) in a
high yield (85%). Dialkyl-substituted secondary amines display
good to excellent yields to the corresponding products (2i-l)
with the yields of 71%-90%.
Table 2. Substrate scope.a
2a (87%)
2e (67%)
2i (90%)
2b (77%)
2f (95%)
2j (72%)b
2c (82%)
2g (75%)
2k (71%)b
2d (78%)
2h (85%)
2l (71%)b
Figure 7. The possible reaction mechanism of CO2 hydrosilylation.
aReaction condition: CO2 (1 atm), 1 (1 mmol), Ir-PCN-222 (0.8 mol%),
PhSiH3 (2 mmol, 216 mg), Cs2CO3 (0.018 mmol, 6 mg), THF (2 mL), R.T.
for 24-48 h. The yields are isolated yield; bThe yield is the conversion of 1
to 2, which is determined by 1H NMR using 1,3,5-trimethoxybenzene as an
internal standard.
To elucidate the reaction pathway, the energy barriers of the
transit states of these steps that control the speed of reaction as
rate-determining processes are calculated. For each pathway,
there might be one hydrogen transfer from PhSiH3 to CO2 (TS1
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(3) Aresta, M.; Dibenedetto, A.; Quaranta, E. State of the art and
in inner sphere or TS1 in outer spere). Moreover, to depict the
perspectives in catalytic processes for CO2 conversion into chemicals
and fuels: The distinctive contribution of chemical catalysis and
Biotechnology. J. Catal. 2016, 343, 2–45.
(4) Chen, J.; McGraw, M.; Chen, E. Y.-X. Diverse catalytic systems
and mechanistic pathways for hydrosilylative reduction of CO2.
ChemSusChem 2019, 12, 4543–4569.
(5) González-Sebastián, L.; Flores-Alamo, M.; García, J. J. Nickel-
Catalyzed Hydrosilylation of CO2 in the Presence of Et3B for the
Synthesis of Formic Acid and Related Formates. Organometallics 2013,
32, 7186–7194.
1
2
3
4
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8
synergistic catalysis of Au clusters and Ir-PCN-222, an Au4
cluster in transit states near the hydrogen transferring process is
modelled. The corresponding energy barriers ΔGr are listed in
Table S4, from which the inner sphere pathway (ΔGr = 118.50
kJmol-1) is expected to be more beneficial than the outer sphere
pathway (ΔGr = 123.71 kJmol-1). Nevertheless, the outer sphere
pathway may not be completely ruled out due to the small
energy difference.
9
(6) Fan, T.; Sheong, F. K.; Lin, Z. DFT Studies on Copper-Catalyzed
Hydrocarboxylation of Alkynes Using CO2 and Hydrosilanes.
Organometallics 2013, 32, 5224–5230.
4. CONCLUSION
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In conclusion, a porphyrin metal-organic framework (PMOF)
composite, Au@Ir-PCN-222, is found to be an effective catalyst
for CO2 hydrosilylation under mild conditions (R. T. and 1 atm),
which might benefit from the synergistic catalysis of Ir-
porphyrin units and Au NPs. Theoretical studies disclose the
CO2 molecules can be stored in the micro channels of Ir-PCN-
222, and then diffuse to the meso channels where the catalytic
reactions occur. Our work provides a useful strategy to integrate
multiple functional components into MOFs for the
combinatorial CO2 adsorption and activation. Further work
about the design and catalytic applications of PMOFs is on the
process.
(7) Liu, X.-F.; Li, X.-Y.; He, L.-N. Transition Metal-Catalyzed
Reductive Functionalization of CO2. Eur. J. Org. Chem. 2019, 2437–
2447.
(8) Park, S.; Bézier, D.; Brookhart, M. An efficient iridium catalyst for
reduction of carbon dioxide to methane with trialkylsilanes. J. Am.
Chem. Soc. 2012, 134, 11404−11407.
(9) Matsuo, T.; Kawaguchi, H. From carbon dioxide to methane:
Homogeneous reduction of carbon dioxide with hydrosilanes catalyzed
by zirconium-borane complexes. J. Am. Chem. Soc. 2006, 128,
12362−12363.
(10) Steinhoff, P.; Paul, M.; Schroers, J. P.; Tauchert, M. E. Highly
efficient palladium-catalysed carbon dioxide hydrosilylation
employing PMP ligands. Dalton Trans. 2019, 48, 1017–1022.
(11) Frogneux, X.; Jacquet, O.; Cantat, T. Iron-catalyzed
hydrosilylation of CO2: CO2 conversion to formamides and
methylamines. Catal. Sci. Technol. 2014, 4, 1529–1533.
(12) Huang, Z.; Jiang, X.; Zhou, S.; Yang, P.; Du, C.-X.; Li, Y. Mn-
catalyzed selective double and mono-N-Formylation and N-
Methylation of amines by using CO2. ChemSusChem 2019, 12, 3054–
3059
(13) Tüchler, M.; Gärtner, L.; Fischer, S.; Boese, A. D.; Belaj, F.;
Mösch-Zanetti, N. C. Efficient CO2 insertion and reduction catalyzed
by a terminal zinc hydride complex. Angew. Chem. Int. Ed. 2018, 57,
6906–6909.
(14) Jacquet, O.; Das Neves Gomes, C.; Ephritikhine, M.; Cantat, T.
Recycling of carbon and silicon wastes: Room temperature formylation
of N−H bonds using carbon dioxide and polymethylhydrosiloxane. J.
Am. Chem. Soc. 2012, 134, 2934−2937.
ASSOCIATED CONTENT
Supporting Information. Physical characterizations of catalysts,
CO2 adsorption and diffusion, catalysis and reaction mechanism,
and characteriations of formamides. This material is available free
of charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
zhli99@mail.sysu.edu.cn;
cesscy@mail.sysu.edu.cn
Author Contributions
(15) Zhou, Q.; Li, Y. The real role of N‑heterocyclic carbene in
reductive functionalization of CO2: An alternative understanding from
density functional theory study. J. Am. Chem. Soc. 2015, 137,
10182−10189.
(16) Chong, C. C.; Kinjo, R. Hydrophosphination of CO2 and
subsequent formate transfer in the 1,3,2-diazaphospholene-catalyzed
N-formylation of amines. Angew. Chem. Int. Ed. 2015, 54, 12116–
12120.
+These authors contributed equally.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENT
(17) Hota, P. K.; Sau, S. C.; Mandal, S. K. Metal-free catalytic
formylation of amides using CO2 under ambient conditions. ACS Catal.
2018, 8, 11999−12003.
The authors acknowledge support from the National Natural
Science Foundation of China (21773314, 21720102007, 21821003,
and 21890380), the Guangdong Natural Science Funds for
Distinguished Young Scholar (2019B151502017), the Tip-top
Youth Talents of Guangdong special support program (No.
20173100042150021), Science and Technology Planning Project
of Guangzhou (201707010168), the General Financial Grant from
the China Postdoctoral Science Foundation (2019M662809), and
Local Innovative and Research Teams Project of Guangdong Peal
River Talents Program (2017BT01C161).
(18) Zhang, X.; Sun, J.; Wei, G.; Liu, Z.; Yang, H.; Wang, K.; Fei, H.
In situ generation of an N-heterocyclic carbene functionalized metal–
organic framework by postsynthetic ligand exchange: efficient and
selective hydrosilylation of CO2. Angew. Chem. 2019, 131, 2870–2875.
(19) Zhang, X.; Jiang, Y.; Fei, H. UiO-type metal–organic frameworks
with NHC or metal–NHC functionalities for N-methylation using CO2
as the carbon source. Chem. Commun. 2019, 55, 11928–11931.
(20) Zhu, N.-X.; Wei, Z.-W.; Chen, C.-X.; Wang, D.; Cao, C.-C.; Qiu,
Q.-F.; Jiang, J.-J.; Wang, H.-P.; Su, C.-Y. Self-generation of surface
roughness by low-surface-energy alkyl chains for highly stable
superhydrophobic/superoleophilic MOFs with multiple functionalities.
Angew. Chem. Int. Ed. 2019, 58, 17033–17040.
(21) Cao, C.-C.; Chen, C.-X.; Wei, Z.-W.; Qiu, Q.-F.; Zhu, N.-X.;
Xiong, Y.-Y.; Jiang, J.-J.; Wang, D.; Su, C.-Y. Catalysis through
Dynamic Spacer Installation of Multivariate Functionalities in Metal-
Organic Frameworks. J. Am. Chem. Soc. 2019, 141, 2589−2593.
(22) Luo, Y.-C.; Chu, K.-L.; Shi, J.-Y.; Wu, D.-J.; Wang, X.-D.; Mayor,
M.; Su, C.-Y. Heterogenization of photochemical molecular devices:
REFERENCES
(1) Ding, M.; Flaig, R. W.; Jiang, H.-L.; Yaghi, O. M. Carbon capture
and conversion using metal–organic frameworks and MOF-based
materials. Chem. Soc. Rev. 2019, 48, 2783–2828.
(2) González-Sebastián, F. J.; Aitani, A. M.; Oro, L. A. Homogeneous
catalytic reduction of CO2 with hydrosilanes. Catal. Sci. Technol. 2014,
4, 611–624.
ACS Paragon Plus Environment

Journal of the American Chemical Society
Page 8 of 10
embedding a metal−organic cage into a ZIF-8-derived matrix to
(41) Liu, G.; Cui, H.; Wang, S.; Zhang, L.; Su, C.-Y. A series of highly
promote proton and electron transfer. J. Am. Chem. Soc. 2019, 141,
13057−13065.
(23) Trickett, C. A.; Helal, A.; Al-Maythalony, B. A.; Yamani, Z. H.
Cordova, K. E.; Yaghi, O. M. The chemistry of metal–organic
frameworks for CO2 capture, regeneration and conversion. Nat. Rev.
Mater. 2017, 2, 17045.
(24) Li, G.; Zhao, S.; Zhang, Y.; Tang, Z. Metal–Organic Frameworks
Encapsulating Active Nanoparticles as Emerging Composites for
Catalysis: Recent Progress and Perspectives. Adv. Mater. 2018,
1800702.
(25) Liu, X.; Sun, L.; Deng, W.-Q. Theoretical investigation of CO2
adsorption and dissociation on low index surfaces of transition metals.
J. Phys. Chem. C 2018, 122, 8306–8314.
(26) Hou, S.-J.; Dong, J.; Zhao, B. Formation of C-X Bonds in CO2
chemical fixation catalyzed by metal–organic frameworks. Adv. Mater.
2019, 1806163.
(27) Liang, J.; Huang, Y.-B.; Cao, R. Metal–organic frameworks and
porous organic polymers for sustainable fixation of carbon dioxide into
cyclic carbonates. Coord. Chem. Rev. 2019, 378, 32–65.
(28) Zhao, M., Yuan, K.; Wang, Y.; Li, G.; Guo, J.; Gu, L.; Hu, W.;
Zhao, H.; Tang, Z. Metal–organic frameworks as selectivity regulators
for hydrogenation reactions. Nature 2016, 539, 76–80.
(29) Rungtaweevoranit, B.; Baek, J.; Araujo, J. R.; Archanjo, B. S.;
Choi, K. M.; Yaghi, O. M.; Somorjai, G. A. Copper nanocrystals
encapsulated in Zr-based metal−organic frameworks for highly
selective CO2 hydrogenation to methanol. Nano Lett. 2016, 16,
7645−7649.
(30) Yoshimaru, S.; Sadakiyo, M.; Staykov, A.; Katoc, K.; Yamauchi,
M. Modulation of the catalytic activity of Pt nanoparticles through
charge-transfer interactions with metal–organic frameworks. Chem.
Commun. 2017, 53, 6720–6723.
(31) Kobayashi, H.; Taylor, J. M.; Mitsuka, Y.; Ogiwara, N.;
Yamamoto, T.; Toriyama, T.; Matsumura, S.; Kitagawa, H. Charge
transfer dependence on CO2 hydrogenation activity to methanol in Cu
nanoparticles covered with metal–organic framework systems. Chem.
Sci. 2019, 10, 3289–3294.
(32) Corey, J. Y. Reactions of Hydrosilanes with Transition Metal
Complexes and Characterization of the Products. Chem. Rev. 2011, 111,
863–1071.
(33) Chen, J.; McGraw, M.; Chen, E. Y.-X. Diverse catalytic systems
and mechanistic pathways for hydrosilylative reduction of CO2.
ChemSusChem 2019, 12, 4543–4569.
(34) Liu, J.; Chen, L.; Cui, H.; Zhang, J.; Zhang, L.; Su, C,-Y.
Applications of metal–organic frameworks in heterogeneous
supramolecular catalysis. Chem. Soc. Rev. 2014, 43, 6011–6061.
(35) Zhang, L.; Liu, J.; Su, C.-Y. Application of metal-organic
frameworks in CO2 capture and conversion. Noncovalent interactions
in catalysis. Catalysis Series No. 36. The Royal Society of Chemistry
2019, 455–478.
(36) Zhang, L.; Liu, J.; Su, C.-Y. Porphyrin metal–organic frameworks
in heterogeneous supramolecular catalysis. Series on Chemistry,
Energy and the Environment V7, World Scientific Publishing Co Pte
Ltd 2020, 225–265.
(37) Liu, J.; Fan, Y.-Z.; Li, X.; Wei, Z.; Xu, Y.-W.; Zhang, L.; Su, C.-
Y. A porous rhodium(III)-porphyrin metal-organic framework as an
efficient and selective photocatalyst for CO2 reduction. Appl. Catal. B
2018, 231, 173–181.
(38) Liu, J.; Fan, Y.-Z.; Li, X.; Xu, Y.-W.; Zhang, L.; Su, C.-Y.
Catalytic space engineering of porphyrin metal–organic frameworks
for combined CO2 capture and conversion at a low concentration.
ChemSusChem 2018, 11, 2340–2347.
(39) Wang, Y.; Cui, H.; Wei, Z.-W.; Wang, H.-P.; Zhang, L.; Su, C.-
Y. Engineering catalytic coordination space in a chemically stable Ir-
porphyrin MOF with a confinement effect inverting conventional Si–H
insertion chemoselectivity. Chem. Sci. 2017, 8, 775–780.
(40) Li, S.; Mei, H.-M.; Yao, S.-L.; Chen, Z.-Y.; Lu, Y.-L.; Zhang, L.;
Su, C.-Y. Well-distributed Pt-nanoparticles within confined
coordination interspaces of self-sensitized porphyrin metal–organic
frameworks: synergistic effect boosting highly efficient photocatalytic
hydrogen evolution reaction. Chem. Sci. 2019, 10, 10577–10585.
stable porphyrinic metal-organic frameworks based on iron-oxo chain
cluster: design, synthesis and biomimetic catalysis, J. Mater. Chem. A
2020, 8, 8376-8382.
(42) Feng, D.; Gu, Z.-Y.; Li, J.-R.; Jiang, H.-L.; Wei, Z.; Zhou, H.-C.
Zirconium-metalloporphyrin PCN-222: mesoporous metal-organic
frameworks with ultrahigh stability as biomimetic catalysts. Angew.
Chem. Int. Ed. 2012, 51, 10307–10310.
(43) Morris, W.; Volosskiy, B.; Demir, S.; Gándara, F.; McGrier, P. L.;
Furukawa, H.; Cascio, D.; Stoddart, J. F.; Yaghi, O. M. Synthesis,
structure, and metalation of two new highly porous zirconium
metal−organic frameworks. Inorg. Chem. 2012, 51, 6443−6445.
(44) Chen, Y.; Hoang, T.; Ma, S. Biomimetic catalysis of a porous iron-
based metal−metalloporphyrin framework. Inorg. Chem. 2012, 51,
12600−12602.
(45) Volosskiy, B.; Niwa, K.; Chen, Y.; Zhao, Z.; Weiss, N. O.; Zhong,
X.; Ding, M.; Lee, C.; Huang, Y.; Duan, X. Metal-organic framework
templated synthesis of ultrathin, well-aligned metallic nanowires. ACS
Nano 2015, 9, 3044-3049.
(46) Chen, Y.-Z.; Jiang, H.-L. Porphyrinic metal−organic framework
catalyzed heck-reaction: Fluorescence “turn-on” sensing of Cu(II) ion.
Chem. Mater. 2016, 28, 6698−6704.
(47) Wang, Q.; Xu, R.; Wang, X.-S.; Liu, S.-D.; Huang, Y.-B.; Cao, R.
Platinum nanoparticle-decorated porous porphyrin-based metal-
organic framework for photocatalytic hydrogen production. Chinese J.
Inorg. Chem. 2017, 33, 2038−2044.
(48) Hutter, J.; Lannuzzi, M.; Sciffmann, F.; VandeVondele, J. CP2K:
atomistic simulations of condensed matter systems. Wiley Interdiscip
Rev. Comput. Mol. Sci. 2014, 4, 15−25.
(49) Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradient
approximation made simple. Phys. Rev. Lett. 1996, 77, 3865−3868.
(50) Joost, V.; Hutter, J. Gaussian basis sets for accurate calculations
on molecular systems in gas and condensed phases. J. Chem. Phys.
2007, 127, 114105.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(51) Goedecker, S.; Teter, M.; Hutter, J. Separable dual-space Gaussian
pseudopotentials. Phys. Rev. B. 1996, 54, 1703−1710.
(52) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb,
M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci, B.;
Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H. P.;
Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.;
Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima,
T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, J. A. J.;
Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin,
K. N.; Staroverov, V. N.; Keith, T.; Kobayashi, R.; Normand, J.;
Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.;
Cossi, M.; Rega, N.; Millam, J. M.; Klene, M.; Knox, J. E.; Cross, J.
B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R.
E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.;
Martin, R. L.; Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador,
P.; Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, O.;
Foresman, J. B.; Ortiz, J. V.; Cioslowski, J.; Fox, D. J., Gaussian 09,
Revision D.01; Gaussian, Inc.: Wallingford, CT, 2013.
(53) Breneman, C. M.; Wiberg, K. B. Determining atom-centered
monopoles from molecular electrostatic potentials-the need for high
sampling density in formamide conformational-analysis. J. Comput.
Chem, 1990, 11, 361−73.
(54) Zhao, Y.; Truhlar, D. G.; A new local density functional for main-
group thermochemistry, transition metal bonding, thermochemical
kinetics, and noncovalent interactions, J. Chem. Phys. 2006, 125, 1−18.
(55) Binning, R. C.; Curtiss, L. A. Compact contracted basis-sets for
3rd-row atoms -GA-KR, J. Comput. Chem. 1990, 11, 1206−16.
(56) Wedig, U.; Dolg, M.; Stoll, H.; Preuss, H. Quantum chemistry: the
challenge of transition metals and coordination chemistry[M]. Springer,
Dordrecht, 1986, 79−89.
(57) Batsanov, S. Van der Waals radii of elements. Inorg. Mater. 2001,
37, 871−885.
(58) Garzón, I. L.; Michaelian, K.; Beltrán, M. R.; Posada-Amarillas,
A.; Ordejón, P.; Artacho, E.; Sánchez-Portal, D.; Soler J. M. Lowest
energy structures of gold nanoclusters. Phys. Rev. Lett. 1998, 81,
1600−1603.
ACS Paragon Plus Environment

Page 9 of 10
Journal of the American Chemical Society
(59) Zhang, Y.; Yang, W. Comment on "Generalized gradient
(70) Skoulidas, A. I.; Sholl, D. S. Transport diffusivities of CH4, CF4,
He, Ne, Ar, Xe, and SF6 in silicalite from atomistic simulations. J. Phys.
Chem. B. 2002, 106, 5058−5067.
(71) Weigend, F.; Ahlrichs, R. Balanced basis sets of split valence,
triple zeta valence and quadruple zeta valence quality for H to Rn:
Design and assessment of accuracy. Phys. Chem. Chem. Phys. 2005, 7,
3297−3305.
approximation made simple". Phys. Rev. Lett. 1998, 80, 890.
(60) Rappé, A. K.; Casewit, C. J.; Colwell, K. S.; Goddard III, W. A.;
Skiff, W. M. UFF, a full periodic table force field for molecular
mechanics and molecular dynamics simulations. J. Am. Chem. Soc.
1992, 114, 10024−10035.
(61) Mayo, S. L.; Olafson, B. D.; Goddard, W. A. DREIDING: a
generic force field for molecular simulations. J. Phys. Chem. 1990, 94,
8897−8909.
1
2
3
4
5
6
(72) Weigend, F. Accurate Coulomb-fitting basis sets for H to Rn. Phys.
Chem. Chem. Phys. 2006, 8, 1057−1065.
7
8
9
(62) Harris, J. G.; Yung, K. H. Carbon dioxide's liquid-vapor
coexistence curve and critical properties as predicted by a simple
molecular model. J. Phys. Chem. 1995, 99, 12021−12024.
(63) Peng, D.-Y.; Robinson, D. B.; A new two-constant equation of
state. Ind. Eng. Chem. Res. 1976, 15, 59−64.
(64) Yang, Q.; Zhong, C. Molecular simulation of carbon dioxide /
methane / hydrogen mixture adsorption in metal-organic frameworks.
J. Phys. Chem. B. 2006, 110, 17776−17783.
(65) Vlugt, T. J. H.; Garcia-Perez, E.; Dubbeldam, D.; Ban, S.; Calero,
S. Computing the heat of adsorption using molecular simulations: the
effect of strong Coulombic interactions. J. Chem. Theo. Comput. 2008,
4, 1107−1118.
(73) Lu, X.; Rycenga, M.; Skrabalak, S. E.; Wiley, B.; Xia, Y.
Chemical synthesis of novel plasmonic nanoparticles. Annu. Rev. Phys.
Chem. 2009, 60, 167–92.
(74) Řezáč J., Hobza P. Advanced corrections of hydrogen bonding and
dispersion for semiempirical quantum mechanical methods. J. Chem.
Theo. Comput. 2012, 8, 141–151.
(75) Plant, D.; Jobic, H.; Llewellyn, P.; Maurin, G. Diffusion of CO2 in
NaY and NaX faujasite systems: quasi-elastic neutron scattering
experiments and molecular dynamics simulations. Eur. Phys. J. Spec.
Top. 2007, 141, 127–132.
(76) Yang, Q.; Jobic, H.; Salles, F.; Kolokolov, D.; Guillerm, V.; Serre,
C.; Maurin, G. Probing the Dynamics of CO2 and CH4 within the
Porous Zirconium Terephthalate UiO-66(Zr): A Synergic Combination
of Neutron Scattering Measurements and Molecular Simulations.
Chem.-Eur. J. 2011, 17, 8882–8889.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(66) http:/lammps. sandia. gov.
(67) Schneider T.; Stoll E. Molecular-dynamics study of a three-
dimensional one-component model for distortive phase transitions.
Phys. Rev. B. 1978, 17, 1302−1322.
(68) Kantorovich, L. Generalized Langevin equation for solids. I.
Rigorous derivation and main properties. Phys. Rev. B. 2008, 78,
094304.
(69) Myshakin, E. M.; Saidi, W. A.; Romanov, V. N. Cygan, R. T.;
Jordan, K. D. J. Molecular dynamics simulations of carbon dioxide
intercalation in hydrated Na-montmorillonite. Phys. Chem. C 2013,
117, 21, 11028-11039.
(77) Wang, S.-G.; Liao, X.-Y.; Cao, D.-B.; Huo, C.-F.; Li, Y.-W.;
Wang, J.; Jiao, H. Factors controlling the interaction of CO2 with
transition metal surfaces. J. Phys. Chem. C 2007, 111, 16934–16940.
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