8986 J. Phys. Chem. B, Vol. 106, No. 35, 2002
Kuroda et al.
the initial adsorption heat of 100 kJ mol-1 is in fairly good
agreement with the data reported by Meyer et al. for the gaseous
monocarbonyl silver-ion complex.28 A few groups also reported
the bond energies of M-CO in [Cu(CO)]+ and [Ag(CO)]+.28,58,59
They also pointed out that the complex [Ag(CO)2]+ is energeti-
cally more stable than [Ag(CO)]+, as is quite different from
the present case. In addition, Strauss described that the π-bond-
ing type of interaction is operative in the copper carbonyl-
complexes and σ-bonding in the silver carbonyl-complexes,57
which are also different from our cases.36 On the other hand,
Veldkamp and Frenking pointed out the contribution of electro-
static interaction even in the silver carbonyl-complex system,
[Ag(CO)]+.60 In the present stage, we have interpreted that the
difference in interaction type between these carbonyl complexes
and zeolite systems may be explained by taking account of the
Wall effect (Pauli’s repulsion).61,62 As a result, it is reasonable
to conclude that the operating force between the silver ion and
CO molecule in the AgZSM-5-CO system is dominantly the
electrostatic force. The difference in bonding nature between
Ag+-CO and Cu+-CO has become apparent in this study; in
other words, the copper ion in zeolite has a specificity.
of Osaka University for technical assistance in making the in
situ glass cell for IR and XAFS measurements.
References and Notes
(1) Adkins, H.; Connor, R. J. Am. Chem. Soc. 1931, 53, 1091; Adkins,
H.; Folkers, K. J. Am. Chem. Soc. 1931, 53, 1095.
(2) Klier, K. AdV. Catal. 1982, 31, 243.
(3) Solomon, E. I.; Jones, P. M.; May, J. A. Chem. ReV. 1993, 93,
2623.
(4) Kung, H. H. Transition Metal Oxides: Surface Chemistry and
Catalysis; Elsevier: Amsterdam, 1989.
(5) Iwamoto, M.; Furukawa, H.; Mine, Y.; Uemura, F.; Mikuriya, S.;
Kagawa, S. J. Chem. Soc., Chem. Commun. 1986, 1272.
(6) Iwamoto, M.; Yahiro, H. Catal. Today 1994, 22, 5.
(7) Li, Y.; Hall, W. K. J. Phys. Chem. 1990, 94, 6145; J. Catal. 1991,
129, 202.
(8) Shelef, M. Catal. Lett. 1992, 15, 305; Chem. ReV. 1995, 95, 209.
(9) Kuroda, Y.; Konno, S.; Morimoto, K.; Yoshikawa, Y. J. Chem.
Soc., Chem. Commun. 1993, 18.
(10) Kuroda, Y.; Yoshikawa, Y.; Konno, S.; Hamano, H.; Maeda, H.;
Kumashiro, R.; Nagao, M. J. Phys. Chem. 1995, 99, 10621.
(11) Spoto, G.; Bordiga, S.; Ricchiardi, G.; Scarano, D.; Zecchina, A.;
Geobaldo, F. J. Chem. Soc., Faraday Trans. 1995, 91, 3285.
(12) Kuroda, Y.; Yoshikawa, Y.; Emura, S.; Kumashiro, R.; Nagao, M.
J. Phys. Chem. B 1999, 103, 2155.
(13) Matsuoka, M.; Matsuda, M.; Tsuji, K.; Yamashita, H.; Anpo, M.
J. Mol. Catal. A 1996, 107, 399.
(14) Anpo, M.; Matsuoka, M.; Yamashita, H. Catal. Today 1997, 35,
177.
Conclusions
(15) Anpo, M.; Zhang, S. G.; Mishima, H.; Matsuoka, M.; Yamashita,
H. Catal. Today 1997, 39, 159.
(16) Matsuoka, M.; Ju, W.-S.; Anpo, M. Chem. Lett. 2000, 626.
(17) Kannan, S. M.; Omary, M. A.; Patterson, H. H.; Matsuoka, M.;
Anpo, M. J. Phys. Chem. B 2000, 104, 3507.
(18) Kuroda, Y.; Mori, T.; Yoshikawa, Y.; Kittaka, S.; Kumashiro, R.;
Nagao, M. Phys. Chem. Chem. Phys. 1999, 1, 3807; Kuroda, Y.; Mori, T.;
Yoshikawa, Y. Chem. Commun. 2001, 1006.
In this study we have examined the properties of silver ion-
exchanged zeolite by IR technique in combination with micro-
calorimetry and tried to picture the bonding nature between Ag+
and CO, as well as to get some information on the prominent
feature (specificity) of the electronic state of the copper ion
exchanged in ZSM-type zeolite. Some useful information
obtained is as follows:
(19) Maeda, H. J. Phys. Soc. Jpn. 1987, 56, 2777.
(20) Becke, A. D. J. Chem. Phys. 1993, 98, 1372; Gill, P. M. W.;
Johnson, B. G.; Pople, J. A. Int. J. Quantum Chem. Symp. 1992, 26, 319.
(21) Slater, J. C. Phys. ReV. 1951, 81, 385.
1. The Brønsted-acid type sites play an important role in
determining the electronic state of the silver-ion exchanged or
deposited on ZSM-5, SiO2‚Al2O3, and SiO2.
(22) Becke, A. D. Phys. ReV. 1988, A38, 3098.
(23) Vosko, S. H.; Wilk, L.; Nusair, M. Can. J. Chem. 1980, 58, 1200;
Wilk, L.; Vosko, S. H. J. Phys. C: Solid State Phys. 1980, 15, 2139.
(24) Lee, C.; Yang, W.; Parr, R. G. Phys. ReV. 1988, B37, 785.
(25) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb,
M. A.; Cheeseman, J. R.; Zakrzewski, V. G.; Montgomery, J. A., Jr.;
Startmann, R. E.; Burant, J. C.; Dapprich, S.; Millam, J. M.; Daniels, A.
D.; Kudin, K. N.; Strain, M. C.; Farkas, O.; Tomasi, J.; Barone, V.; Cossi,
M.; Cammi, R.; Mennucci, B.; Pomelli, C.; Adamo, C.; Clifford, S.;
Ochterski, J.; Petersson, G. A.; Ayala, P. Y.; Cui, Q.; Morokuma, K.; Malick,
D. K.; Rubuck, A. D.; Raghavachari, K.; Foresman, J. B.; Cioslowski, J.;
Ortiz, J. V.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi,
I.; Gomperts, R.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.;
Peng, C. Y.; Nanayakkara, A.; Gonzalez, C.; Challacombe, M.; Gill, P. M.
W.; Johnson, B. G.; Chen, W.; Wong, M. W.; Andres, J. L.; Gonalez, C.;
Head-Gordon, M.; Replogle, E. S.; Pople, J. A. Gaussian 98, Revision A.5;
Gaussian, Inc.: Pittsburgh, PA, 1998.
2. From the relationship between qdiff and νCO, the position
of the IR band due to the adsorbed CO species is well explained
on the basis of the concept of electrostatic attraction, as is
different from the case of CuZSM-5-CO system in which
σ-bonding is dominantly operative.
3. We assumed two types of models for the silver-ion
exchanged in ZSM-5: two coordination- and three-coordination
sites relating to the Brφnsted acid center. The former sites are
responsible for larger heat values and higher-frequency IR band
when CO molecules are adsorbed. On the other hand, the latter
type of sites acts as weak chemisorption or physisorption sites
to yield smaller adsorption heat and lower IR-band frequency,
corresponding well to the results evaluated by the DFT
calculation.
(26) Hay, P. J.; Wadt, W. R. J. Chem. Phys. 1985, 82, 270; Wadt, W.
R.; Hay, P. J. J. Chem. Phys. 1985, 82, 284; Hay, P. J.; Wadt, W. R. J.
Chem. Phys. 1985, 82, 299.
(27) Cardona-Martinez, N.; Dumesic, J. A. AdV. Catal. 1992, 38, 149.
(28) Meyer, F.; Chen, Y.-M.; Armentrout, P. B. J. Am. Chem. Soc. 1995,
117, 4071.
(29) Lercher, J. A.; Grundling, C.; Eder-Mirth, G. Catal. Today 1996,
27, 353; Zecchina, A.; Arean, C. O. Chem. Soc. ReV. 1996, 187.
(30) Hadjiivanov, K.; Kno¨zinger, H. J. Phys. Chem. B 1998, 102, 10936;
Hadjiivanov, K. Mesoporous Microporous Mater. 1998, 24, 41.
(31) Kumashiro, R.; Kuroda, Y.; Nagao, M. J. Phys. Chem. B 1999,
103, 89.
4. The energy separation between 4d and 5s levels of Ag+ is
expected to be large, as suggested from the larger absorption
energy between 4d10 level and the first excitation 4d95s1 level,
as well as the larger second ionization energy, which is
compared with the case of copper ion (between 3d and 4s). As
a result, it is concluded that the mixing of orbitals of 5s and 4d
levels encounters a great difficulty for the silver ion in ZSM-5
zeolite, resulting in the greater σ-repulsion.
(32) Kuroda, Y.; Kumashiro, R.; Itadani, A.; Nagao, M. Phys. Chem.
Chem. Phys. 2001, 3, 1383.
(33) Kuroda, Y.; Kumashiro, R.; Onishi, H.; Mori, T.; Kobayashi, H.;
Yoshikawa, Y.; Nagao, M. Stud. Surf. Sci. Catal. 2001, 132, 689.
(34) Bordiga, S.; Lamberti, C.; Palomino, G. T.; Geobaaldo, F.; Arduino,
D.; Zecchina, A. Mesoporous Microporous Mater. 1999, 30, 129.
(35) Bordiga, S.; Palomino, G. T.; Arduino, D.; Lamberti, C.; Zecchina,
A.; Arean, C. O. J. Mol. Catal. A 1999, 146, 97.
(36) Kuroda, Y.; Yoshikawa, Y.; Kumashiro, R.; Nagao, M. J. Phys.
Chem. B 1997, 101, 6497.
(37) Zecchina, A.; Scarano, D.; Bordiga, S.; Spoto, G.; Lamberti C. AdV.
Catal. 2001, 46, 265.
Acknowledgment. This work was supported in part by
foundation from Wesco Co. A part of this work has been
performed under the proposal (No. 2001G128) of the Photon
Factory Program Advisory Committee. Thanks are also due to
Profs. M. Nomura, A. Koyama, and N. Usami of the Photon
Factory (KEK) in Tsukuba for their kind assistance in measuring
the XAFS spectra. We also thank the glassblowing workshop