Chapter 10
Vibrational Spectroscopy of Zeolites
Theory Versus Experiment
Magdalena Król, Andrzej Koleżyński, Andrzej Mikuła
and Włodzimierz Mozgawa
Abstract In this chapter, the ab initio calculations have been used to analyze the
structural properties and vibrational spectra of selected zeolites. The spectra obtained
as a result of theoretical calculations along with their interpretation were used to
describe the experimental spectra of real zeolite structures. Presented results show
that in the experimental spectra of zeolites one can distinguish the bands associated
with characteristic vibrations of a bigger element of the structure, composed of
tetrahedra, the primary building blocks. It was also shown that the composite
envelopes of particular bands are significantly affected by component bands associated with characteristic vibrations of building units that form zeolite structures.
10.1 Introduction
According to the classical definition of Smith [1], zeolites are 3D aluminosilicates
frameworks (tectosilicates) with free spaces and channels of strictly defined
molecular sizes in the structure, which can be occupied by cations and small
molecules with a high freedom of motion [2]. The above definition refers mainly to
natural zeolites, but it is worth to mention that among synthetic zeolites one can
also distinguish structures in which tetrahedral positions are occupied by other
cations like germanium or phosphorus (e.g., [3]).
Zeolites can be also defined as crystalline, inorganic spatial polymers consisting
of corner-shared tetrahedra [TO 4 ]. Since in a part of tetrahedra silicon atoms are
substituted heterovalently by aluminum, the whole structure shows a positive charge
deficit and contains charge compensating extra-framework cations, mainly from
groups I and II of the periodic table (Na
+
, K
+
, Mg
2+ , Ca
2+ , Sr
2+ , Ba
2+ , etc.) [4, 5].
Both the Si/Al ratio and the content of extra-framework cations affect the properties
of zeolites [2], and so continuously conducted research on these valuable and
M. Król (&) Á A. Koleżyński Á A. Mikuła Á W. Mozgawa
Faculty of Materials Science and Ceramics, AGH University of Science
and Technology, 30 Mickiewicza Av., 30-059 Krakow, Poland
e-mail: mkrol@agh.edu.pl
© Springer Nature Switzerland AG 2019
A. Koleżyński and M. Król (eds.), Molecular Spectroscopy—Experiment
and Theory, Challenges and Advances in Computational Chemistry
and Physics 26, https://doi.org/10.1007/978-3-030-01355-4_10
301
Vibrational Spectroscopy of Zeolites
Theory Versus Experiment
Magdalena Król, Andrzej Koleżyński, Andrzej Mikuła
and Włodzimierz Mozgawa
Abstract In this chapter, the ab initio calculations have been used to analyze the
structural properties and vibrational spectra of selected zeolites. The spectra obtained
as a result of theoretical calculations along with their interpretation were used to
describe the experimental spectra of real zeolite structures. Presented results show
that in the experimental spectra of zeolites one can distinguish the bands associated
with characteristic vibrations of a bigger element of the structure, composed of
tetrahedra, the primary building blocks. It was also shown that the composite
envelopes of particular bands are significantly affected by component bands associated with characteristic vibrations of building units that form zeolite structures.
10.1 Introduction
According to the classical definition of Smith [1], zeolites are 3D aluminosilicates
frameworks (tectosilicates) with free spaces and channels of strictly defined
molecular sizes in the structure, which can be occupied by cations and small
molecules with a high freedom of motion [2]. The above definition refers mainly to
natural zeolites, but it is worth to mention that among synthetic zeolites one can
also distinguish structures in which tetrahedral positions are occupied by other
cations like germanium or phosphorus (e.g., [3]).
Zeolites can be also defined as crystalline, inorganic spatial polymers consisting
of corner-shared tetrahedra [TO 4 ]. Since in a part of tetrahedra silicon atoms are
substituted heterovalently by aluminum, the whole structure shows a positive charge
deficit and contains charge compensating extra-framework cations, mainly from
groups I and II of the periodic table (Na
+
, K
+
, Mg
2+ , Ca
2+ , Sr
2+ , Ba
2+ , etc.) [4, 5].
Both the Si/Al ratio and the content of extra-framework cations affect the properties
of zeolites [2], and so continuously conducted research on these valuable and
M. Król (&) Á A. Koleżyński Á A. Mikuła Á W. Mozgawa
Faculty of Materials Science and Ceramics, AGH University of Science
and Technology, 30 Mickiewicza Av., 30-059 Krakow, Poland
e-mail: mkrol@agh.edu.pl
© Springer Nature Switzerland AG 2019
A. Koleżyński and M. Król (eds.), Molecular Spectroscopy—Experiment
and Theory, Challenges and Advances in Computational Chemistry
and Physics 26, https://doi.org/10.1007/978-3-030-01355-4_10
301