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Supplementary Materials for original manuscript submitted for
publication in special issue of
International Journal of Quantum Chemistry
Carbonates in zeolites: formation, properties, reactivity
Andrey A. Rybakov*a, Ilya, A. Bryukhanovb, Alexander V. Larina,
Georgy M. Zhidomirova, c
a
Department of Chemistry, Moscow State University, Leninskie Gory, Moscow, GSP-2, Russia
119992; bDepartment of Mechanics and Mathematics, Moscow State University, Leninskie
Gory, Moscow, GSP-2, 119992 Russia; cBoreskov Institute of Catalysis, SB RAS, Novosibirsk,
630090, Russia
Ph. 7-495-939-3952, Fax 7-495-932-8846
TOTAL PAGES 8
TABLE 1
FIGURE 1
*) corresponding
author: [email protected]
S1. Water influence on Cu-carbonate formation
Regarding the easiness of CH4 oxidation over CuOXCu moieties [S1-S4], one can
propose that CO oxidation to CO2 should not be a limiting stage. Then the Cu-carbonate
formation via the reactions between CO2 and CuOXCu moieties can be tested similarly to the
route from EA oxide MeOXMe clusters [S5-S6], X = 1 - 2. The Part 3.2 justifies the application
of the DFT tools relative to our cluster models containing CuOXCu moieties, X = 1 - 2, which
can react to produce the carbonates. We can now check: 1) the activation energy of carbonate
formation due to the reaction between CO2 and CuOCu species and 2) how the reaction of
carbonate formation will depend on the presence of water. A reaction cycle will have additional
attraction if the reaction will not require a high temperature treatment for full dehydration.
The reaction of CO2 and CuOCu-8R(2Al) without water presents a first problem at the
step of the reagents optimization. We have optimized a metastable structure (-3489.990800 a.u.
in Table S1, Fig. S1a) which is less stable than the separated reagents (at infinity) (-3489.998780
a.u. in Table S1) and respective transition state (TS) (Fig. S1b). The Cu-O distance for the
closest O atom of CO2 is 2.498 Å, the latter is tilt relative to one of the cations with a minor
deformation (O-C-O = 177.6°, |C-O| = 1.163 and 1.177 Å). While using the metastable
structure as reagents for the search of the TS geometry with QST3 method [S7], we have
obtained the TS geometry (Fig. S1b) with required frequency of 268i cm-1 which is more stable
than the structure (Fig. S1a) but less stable than separated reagents (Table 8). If one use the
energy of the separated reagents as the estimation of the reagent energy, then the activation
barrier for the CuCO3Cu formation can be conventionally evaluated Ea < 2.36 kcal/mol without
water. This small barrier shows quick trapping of CO2 by CuOCu at room temperature.
This activation energy rises only up to 5.18 kcal/mol if one water molecule is coordinated
to the Cu cation of CuOCu-8R(2Al) which is not linked to CO2 (Fig. S1f). Such structure with
non-dissociated water (Fig. S1f) remains more stable (as much as by 18.09 kcal/mol) than
possible hydrocarbonate (HO)CuНCO3Cu(8R) (Fig. S1g). We did not succeed to find the TS
geometry for its transformation into (H2O)CuCO3Cu(8R) using cluster approach. Once looking
for a stable configuration for dissociated water with proton at the O atom of the 8R ring we
observed the easy recombination of water and thus obtained more symmetric and more stable
carbonate geometry together with water (Fig. S1j) than the asymmetric one (Fig. S1f) achieved
via the reaction of CuOCu with CO2 (Fig. S1c, f) whose configuration does not depends on the
presence of adsorbed water. In the terms of  (Eq. 1) asymmetry parameter, this more symmetric
carbonate possesses  of 0.083 Å (Fig. S1j) instead of 0.243 Å for asymmetric one. In order to
evaluate respective band splitting (BS) one could address to Fig. 1 of ref. [S8] (or Fig. 4 from
ref. [S9]) where the fitted linear approximation BS() at the B3LYP/6-31G* level is depicted by
dotted line. Then  = 0.083 Å corresponds to the BS value around of 220-230 cm-1 from the
Figure 1 of ref. [S8] that is in good agreement with experimental BS values of 226 cm-1 [S10] or
221 cm-1 [S11]. It signifies that the carbonate (Fig. S1j) suits very well to the spectroscopic data
about the observed species which exists along the DMC formation reaction in CuY [S10-S11]1.
Moreover, carbonate is stable in a reaction with water.
We have observed a moderate reactivity of the CuOCu-8R(2Al) cluster relative to the
water. Its heat of adsorption takes 21.1 kcal/mol without the zero point energy (ZPE) variation.
This heat value is in the usual range for the heats of water adsorption at the zeolites with
transition metal cations [S12]. The minor shift of the ZPE can be evaluated from the ZPE
variation upon adsorption in similar systems, i.e., less than 0.4 and 0.6 kcal/mol at Mg2+ и Ca2+
forms, respectively [S13-S13]. The non-dissociated state is favored for water in the Cu8R(2Al)
cluster with a recombination barrier of 2.3 kcal/mol and imaginary frequency of 1228i cm-1 (Fig.
S1k). In this respect the Cu+2 resembles the EA cations [S13-S13].
However, this more symmetric form slightly varies upon the loss of water (not shown) achieving  = 0.079 Å
being less stable than the asymmetric one (-3490.027523 a.u. in Table 8) by 1.2 kcal/mol.
1
References
[S1] J. S. Woertink, P. J. Smeets, M. H. Groothaert, M. A. Vance, B. F. Sels, R. A. Schoonheydt,
E. I. Solomon, Proc. Natl. Acad. Sci. U. S. A., 2009, 106, 18908–13.
[S2] P. J. Smeets, M. H. Groothaert, R. A. Schoonheydt, Catal. Today, 2005, 110, 303–309.
[S3] M. H. Groothaert, P. J. Smeets, B. F. Sels, P. A. Jacobs, R. A. Schoonheydt, J. Am. Chem.
Soc., 2005, 127, 1394–5.
[S4] P. Vanelderen, R. G. Hadt, P. J. Smeets, E. I. Solomon, R. A. Schoonheydt, B. F. Sels, J.
Catal., 2011, 284, 157–164.
[S5] G. M. Zhidomirov, A. A. Shubin, A.V. Larin, S.I. Malykhin, A. A. Rybakov, Molecular
models of active sites of zeolite catalysts; J. Leszczynski and M.K. Shukla, Eds.; Practical
Aspects of Computational Chemistry I. An Overview of the Last Two Decades and Current
Trends, Springer Science+Business Media B.V., 2012, XV, p. 579-644.
[S6] G. M. Zhidomirov, A. V. Larin, D. N. Trubnikov, D. P. Vercauteren, J. Phys. Chem. C,
2009, 113, 8258–8265.
[S7] M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A. Robb, J. R. Cheeseman,
G. Scalmani, V. Barone, B. Mennucci, G. A. Petersson, H. Nakatsuji, M. Caricato, X. Li, H.
P. Hratchian, A. F. Izmaylov, J. Bloino, G. Zheng, J. L. Sonnenberg, M. Hada, M. Ehara, K.
Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, T.
Vreven, J. A. Montgomery, Jr., J. E. Peralta, F. Ogliaro, M. Bearpark, J. J. Heyd, E. Brothers,
K. N. Kudin, V. N. Staroverov, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, J. C.
Burant, S. S. Iyengar, J. Tomasi, M. Cossi, N. Rega, J. M. Millam, M. Klene, J. E. Knox, J. B.
Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E. Stratmann, O. Yazyev, A. J.
Austin, R. Cammi, C. Pomelli, J. W. Ochterski, R. L. Martin, K. Morokuma, V. G.
Zakrzewski, G. A. Voth, P. Salvador, J. J. Dannenberg, S. Dapprich, A. D. Daniels, Ö.
Farkas, J. B. Foresman, J. V. Ortiz, J. Cioslowski, D. J. Fox, Gaussian 09, Revision A.1,
Gaussian, Inc., Wallingford CT, 2009.
[S8] A. V. Larin, I. A. Bryukhanov, A. A. Rybakov, V. L. Kovalev, D. P. Vercauteren,
Microporous Mesoporous Mater., 2013, 173, 15–21.
[S9] A. V. Larin, Microporous Mesoporous Mater., 2014, 200, 35–45.
[S10] J. Engeldinger, M. Richter, U. Bentrup, Phys. Chem. Chem. Phys., 2012, 14, 2183.
[S11] J. Engeldinger, C. Domke, M. Richter, U. Bentrup, Appl. Catal. A Gen., 2010, 382, 303–
311.
[S12] B.V. Romanovsky, K.V.Topchieva, L.V. Stolyarova, A.M. Alekseev, Kinet. Katal., 1970,
11, 1525−1530.
[S13] A. V. Larin, A. A. Rybakov, G. M. Zhidomirov, J. Phys. Chem. C, 2012, 116, 2399–2410.
[S14] A. A. Rybakov, A. V. Larin, G. M. Zhidomirov, Inorg. Chem., 2012, 51, 12165–12175.
Table S1. The energies (U, kcal/mol) of the formation steps (a.u.) of copper carbonate in the
cluster Z = 8R(2Al) with and without water and activation energy (Ea, kcal/mol). The barriers for
TS are shown in Figure S1. Activation energy or heat of the reactions (given in Fig. S1) are
shown in brackets for TS or products, respectively.
System
-U, a.u.
Figure
<Cu2O-Z + CO2>
<3489.990800>
S1a
Isolated Cu2O-Z and CO2
3489.998780
b)
TS (Ea = <2.4> )
3489.995014
S1b
3490.029590
S1c
Cu2CO3 – Z (U = -24.3)
а)
(H2O)Cu2O-Z + CO2
3566.439243
S1d
TS (Ea = 5.2)
3566.430990
S1e
3566.470210
S1f
(H2O)Cu2CO3 – Z (U = -19.4)
(HO)CuНCO3Cu-Z
3566.441374
S1g
(HO)Cu-O(H)-Cu-Z + CO2
3566.443558
S1h
TS (Ea = 15.7)a)
3566.418523
S1i
(H2O)Cu2CO3 – Z
3566.475126
S1j
Cu2CO3 – Z
3490.027523
(HO)Cu – HZ
3106.462957
TS (Ea = 2.3)
3106.459254
S1k
(H2O)Cu – Z
3106.476524
H2O
76.407024
CO2
188.577570
Cu2O– Z
3301.421210
а)
the reagents are (HO)Cu-O(H)-Cu-Z + CO2 (Fig. S1h), while the product is Cu2CO3 – Z + H2O
(see the text); b) relative to the energy of isolated Cu2O-Z + CO2 species
Figure caption
Figure S1. Local geometries of (a, d, h) reagents, (b, e, i, k) transition states, (c, f, g, j) products
of the reactions between the Cu28R(2Al) cluster and CO2 or/and H2O optimized at the B3LYP/631G* level. Only transition state (k) for H2O dissociation is shown. The arrows connect three
steps of three reactions (reagent  transition state  product, two of them possess a common
product (f)). More data about the structures are collected in Table 8. The atomic colors are given
in blue, red, yellow, magenta, and grey for Cu, O, Si, Al, and H, respectively.
Figure S1
a)
b) Ea < 2.4
c)
d)
e) Ea = 5.2
f)
g)
h)
i) Ea = 15.7
j)
k) Ea = 2.3