Nature of the Active Centers of In-, Zr-, and Zn-Aluminosilicates of the ZSM-5 Zeolite Structural Type
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Abstract
In-, Zr-, and Zn- containing elementoaluminosilicates of ZSM-5 zeolite structural type are synthesized by means of hydrothermal crystallization from alkaline alumina–silica gels. Based on the data of structural morphological studies on the samples, it is established that introducting metals into the zeolite structure leads to the formation of particles different in morphology and elemental composition. Studies of the electronic state of active centers in elementoaluminosilicates (E-AS) show that Zn2+ and In3+ cations are associated with oxygen ions in zeolite channels with bonding energies inherent in their oxides. The high value of Zn 3d bonding energy explains the stability of zinc ions in the Zn-AS structure with no formation of clusters under heating the sample by an electron microscope beam. The isomorphic substitution of Al3+ ions in the zeolite crystal lattice by Zr4+ and In3+ ions, despite the relatively low Zr 3d and In 3d bonding energies, also results in the stability of Zr-AS and In-AS systems. It is found that the aggregation of Zr and In into oxide clusters is observed only under strong heating with the electron beam after the destruction of the zeolite channel structure.
Keywords
zeolite elementoaluminosilicate crystals clusters aggregates morphology active centersPreview
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References
- 1.A. A. Dergachev and A. L. Lapidus, Ros. Khim. Zh. 52 (4), 15 (2008).Google Scholar
- 2.Kh. M. Minachev and A. A. Dergachev, Itogi Nauki Tekh., Kinet. Katal. 23, 3 (1990).Google Scholar
- 3.S. R. Rasulov, G. R. Mustafaeva, and L. A. Makhmudova, Neftepererab. Neftekhim., No. 1, 36 (2012).Google Scholar
- 4.D. Shindo and T. Oikawa, Analytical Electron Microscopy for Materials Science (Sringer, Japan, 2002).CrossRefGoogle Scholar
- 5.B. Fultz and J. M. Howe, Transmission Electron Microscopy and Diffractometry of Materials (Springer, Berlin, Heidelberg, 2008).Google Scholar
- 6.L. Reimer and H. Kohl, Transmission Electron Microscopy: Physics of Image Formation (Springer, New York, 2008).Google Scholar
- 7.The International Centre for Diffraction Data, Database PCPDFWIN (JCPDS-ICDD, 1997).Google Scholar
- 8.J. F. Moulder, W. F. Stickle, P. E. Sobol, et al., Handbook of X-ray Photoelectron Spectroscopy (Perkin-Elmer Corp., Phys. Electron. Div., Eden Prairie, Minnesota, 1992).Google Scholar
- 9.V. I. Nefedov, X-ray Electron Spectroscopy of Chemical Compounds, The Handbook (Khimiya, Moscow, 1984) [in Russian].Google Scholar
- 10.Ch. Baerlocher, L. B. McCusker, and D. H. Olson, Atlas of Zeolite Framework Types (Elsevier, New York, 2007), p. 405.Google Scholar
- 11.K. Nakamoto, Infrared and Raman Spectra of Inorganic and Coordination Compounds (Mir, Moscow, 1991; Wiley, New York, 1986).Google Scholar
- 12.D. V. Shukla and V. P. Pandya, J. Chem. Tech. Biotechnol., No. 44, 147 (1989).CrossRefGoogle Scholar
- 13.D. Breck, Zeolite Molecular Sieves (Wiley, New York, 1974; Mir, Moscow, 1976).Google Scholar
- 14.Methods of Analysis, Studies and Tests of Oils and Oil Products, Ed. by E. M. Nikonorov (Nauka, Moscow, 1986), Pt. 3 [in Russian].Google Scholar
- 15.K. G. Ione, Polyfunctional Catalysis on Zeolites (Nauka, Novosibirsk, 1982) [in Russian].Google Scholar
- 16.L. N. Vosmerikova, A. N. Volynkina, V. I. Zaikovskii, and A. V. Vosmerikov, Key Eng. Mater. 670, 15 (2016). doi 10.4028/www.scientific.net/KEM.670.15CrossRefGoogle Scholar