Abstract
In situ ESR at 120–473 K permits to monitor formation of transient paramagnetic ions/complexes (isolated Pd+ sites; Pd+/H2O; Pd+/C6H6) upon interaction of isolated Pd2+ cations stabilized by the H-ZSM-5 matrix with different organic compounds and gas mixtures (NO, O2, H2O, H2, propene, benzene). The in situ study provides insight into the elementary steps of redox processes on isolated Pd species in H-ZSM-5 zeolite under realistic conditions. Adsorbed water stabilizes the transient paramagnetic complex and decreases the rate of Pd2+ to Pd0 reduction by H2. Strong bonding of NO x ligands to Pd2+ species suppresses the reduction of Pd(II) ions. Sorption of benzene on preoxidized Pd2+/HZSM-5 is accompanied by an easy formation of organic cation-radicals and of a Pd+/benzene complex, the paramagnetic Pd+/benzene structure indicating a surprisingly high resistance to further reduction to Pd0. Illumination of the Pd/HZSM-5 by UV-visible light causes no measurable change in the redox properties of the catalyst.
Similar content being viewed by others
References
A. Fritz andV. Pitchon, Appl. Catal. B 13 (1997) 1.
I.N. Filimonov,I.A. Ikonnikov andA.Yi. Loginov, J. Chem. Soc. Faraday Trans. 90 (1994) 219.
A.W. Aylor,L.J. Lobree,J.A. Reimer andA.T. Bell, J. Catal. 172 (1997) 453.
A. Ali,W. Alvarez,C.J. Loughran andD.E. Resasco, Appl. Catal. B 14 (1997) 13.
J.-S. Yu,C.W. Lee andL. Kevan, J. Phys. Chem. 98 (1994) 5736.
J.-S. Yu,J.-M. Comets andL. Kevan, J. Chem. Soc. Faraday Trans. 89 (1993) 4397.
G.-H. Back,J.-S. Yu,V. Kurshev andL. Kevan, J. Chem. Soc. Faraday Trans. 90 (1994) 2283.
J.-S. Yu andL. Kevan, J. Chem. Soc. Faraday Trans. 91 (1995) 3987.
J.-S. Yu andL. Kevan, Langmuir 11 (1995) 1617.
M. Hartmann andL. Kevan, J. Phys. Chem. 100 (1996) 4606.
M. Narayana,J. Michalik,S. Contarini andL. Kevan, J. Phys. Chem. 89 (1985) 3895.
C.W. Lee,J.-S. Yu andL. Kevan, J. Phys. Chem. 96 (1992) 7747.
L.J. Lobree,A.W. Aylor,J.A. Reimer andA.T. Bell, J. Catal. 181 (1999) 189.
C.J. Loughran andD.E. Resasco, Appl. Catal. B 5 (1995) 351.
C.J. Loughran andD.E. Resasco, Appl. Catal. B 7 (1995) 113.
A. Ali,Y.-H. Chin andD.E. Resasco, Catal. Lett. 56 (1998) 111.
A.V. Kucherov,J.L. Gerlock,H.-W. Jen andM. Shelef, J. Phys. Chem. 98 (1994) 4892.
A.V. Kucherov,C.P. Hubbard andM. Shelef, Catal. Lett. 33 (1995) 91.
A.V. Kucherov,S.G. Lakeev andM. Shelef, Appl. Catal. B 16 (1998) 245.
A.V. Kucherov,S.G. Lakeev andM. Shelef, Micropor. Mesopor. Mater. 20 (1998) 355.
A.V. Kucherov,H.G. Karge andR. Schlögl, Micropor. Mesopor. Mater. 25 (1998) 7.
A.V. Kucherov andM. Shelef, J. Catal. 195 (2000) 106.
A.V. Kucherov andA.A. Slinkin, Kinet. Katal. 38 (1997) 768.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kucherov, A., Shelef, M. An In Situ ESR Study of Pd/H-ZSM-5 Interaction with Different Adsorbents. Catalysis Letters 75, 19–24 (2001). https://doi.org/10.1023/A:1016723804026
Issue Date:
DOI: https://doi.org/10.1023/A:1016723804026