Electronic Supplementary Material (ESI) for Chemical Science
This journal is © The Royal Society of Chemistry 2012
Catalyzed Activation of CO2 by a Lewis Base Site in
W-Cu-BTC Hybrid Metal Organic Frameworks
Qiuju Zhang1, Lujie Cao1, Baihai Li1,2, Liang Chen1*
1
Ningbo Institute of Materials Technology and Engineering, Chinese Academy
of Sciences, Ningbo, Zhejiang 315201, P. R. China
2
Department of Materials Science and Engineering, University of Michigan,
Ann Arbor, MI
* Corresponding Author; [email protected]; Fax:+86-574-86685043
List of Contents:
Figure S1. The periodic and cluster models of W-Cu-BTC.
Figure S2. The binding energies (Eads) and adsorbed geometries of CO2 binding on
Mo-Cu-BTC and Cr-Cu-BTC; and HOMO comparison of M-Cu-BTC
(M=W, Mo and Cr).
Figure S3. The vibrational modes of CO2-adsorbed complexes except for 2(CO).
Figure S4. The local density of states (LDOS) of W-Cu-BTC and 2(CO).
Figure S5. The binding energies and geometries of CO2 binding on W-BTC and
Cu-BTC.
Table S1. Comparison of the adsorption energy (Eads) and geometries of CO2
adsorbed on W-Cu-BTC, Cu-BTC and W-BTC.
Figure S6. The desorption process of formic acid on W-Cu-BTC.
Figure S7. The desorption process of methylene glycol on W-Cu-BTC.
Electronic Supplementary Material (ESI) for Chemical Science
This journal is © The Royal Society of Chemistry 2012
Figure S1. The periodic (a) and cluster (b) models of W-Cu-BTC. The blue, green, red,
grey and white balls represent W, Cu, O, C and H atoms, respectively.
(b)
(a)
Figure S2. (Top) The binding energies/adsorption energies (Eads) and the adsorbed
geometries of CO2 binding on Mo-Cu-BTC and Cr-Cu-BTC. The abilities of
catalyzing CO2 by the three hybrid MOFs are found to be in the order of
W-Cu-BTC > Mo-Cu-BTC > Cr-Cu-BTC. Although the coordination complex 2(CO)
can be formed on Mo-Cu-BTC, the binding energy of 0.44 eV is much smaller than
that of W-Cu-BTC (1.34 eV). In the case of Cr-Cu-BTC, the 2(CO) complex can not
be obtained. Instead, the structural optimization shows a favorable angularly-binding
structure (12(O)) with CO2 remaining the original linear structure (Eads =0.33 eV),
which indicates that the Cr-Cu node is unable to activate CO2. Indeed, as mentioned
in the introduction, the ability to activate CO2 is related to the ability of losing
electrons, which is in the order of Cr < Mo < W.
(Bottom) The comparison of HOMO for W-Cu-BTC, Mo-Cu-BTC and Cr-Cu-BTC.
The gradually weaker dz2 character is well consistent with the weaker catalyzing
ability in the order of W-Cu-BTC > Mo-Cu-BTC > Cr-Cu-BTC.
Electronic Supplementary Material (ESI) for Chemical Science
This journal is © The Royal Society of Chemistry 2012
180
138
2.31
2.08 2.06
Mo
2.67
Cr
2.49
Cu
Cu
CO2···Mo-Cu-BTC (Eads = 0.44 eV)
W-Cu-BTC
CO2···Cr-Cu-BTC (Eads = 0.33 eV)
Mo-Cu-BTC
Cr-Cu-BTC
Figure S3. The vibrational frequency modes of CO2 adsorption on the open metal W
sites in various models except 2(CO).
asym=2376 cm-1
sym=1285 cm-1
11(O)
asym=2372 cm-1
sym=1290 cm-1
12(O)
1bend=510 cm-1
2bend=502 cm-1
1bend=526 cm-1
2bend=575 cm-1
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asym=1749 cm-1
sym=1200 cm-1
1bend=687 cm-1
2bend=677 cm-1
i =252i cm-1
1(C)
asym=1568 cm-1
sym=1269 cm-1
2(OO)
1bend =673 cm-1
2bend =674 cm-1
Electronic Supplementary Material (ESI) for Chemical Science
This journal is © The Royal Society of Chemistry 2012
Figure S4. LDOS of the open W ion in W-Cu-BTC and 2(CO) complex of
CO2-W-Cu-BTC including the 6s, 5dz2 and the 5d orbitals.
(a) W-Cu-BTC
(b) 2(CO)-CO2-W-Cu-BTC
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Figure S5. The physisorbed structures and binding energies/adsorption energies (Eads)
of CO2 angularly and linearly binding on W-BTC (top layer) and Cu-BTC (bottom
layer).
180
180
169
2.44
2.99
2.55
2.14
2.14
11(O) (Eads= 0.07 eV)
12(O) (Eads= 0.06 eV)
180
180
2.46
3.11
2.47
11(O) (Eads = 0.10 eV)
2.49
2.47
12(O) (Eads = 0.13 eV)
Table S1. Comparison of the adsorption energy (Eads) and geometries of CO2
adsorbed on W-Cu-BTC, Cu-BTC and W-BTC.
W-Cu-BTC
Cu-BTC
W-BTC
Eads
COC
Eads
COC
Eads
COC
11(O)
0.22
180
0.10
180
0.07
180
12(O)
0.24
178
0.13
180
0.06
180
1(C)
0.25
144
-
-
-
-
2(CO)
1.34
136
-
-
-
-
2(OO)
-0.40
108
-
-
-
-
Electronic Supplementary Material (ESI) for Chemical Science
This journal is © The Royal Society of Chemistry 2012
Figure S6. The desorption process of formic acid (HCOOH) from W-Cu-BTC after
hydrogenation by two H atoms on the activated CO2 in 2(CO) complex.
0.00
Separation
Relative Energy (eV)
-0.10
-0.20
Physisorption
2.21
-0.30
3.75
-0.40
4.07
Eads = -0.54 eV
-0.50
-0.60
Adsorption
Eads = -0.16 eV
HCOOH Desorption Process
Figure S7. The desorption process of methylene glycol (H2C(OH)2) from W-Cu-BTC
after hydrogenation by four H atoms on the activated CO2 in 2(CO) complex.
Relative Energy (eV)
0.00
Separation
Physisorption
-0.20
2.20
-0.40
4.07
4.17
-0.60
Eads = -0.88 eV
-0.80
Adsorption
-1.00
Eads = -0.17 eV
H2C(OH)2 Desorption Process