TY - JOUR

T1 - Nature of the Active Centers of In-, Zr-, and Zn-Aluminosilicates of the ZSM-5 Zeolite Structural Type

AU - Zaikovskii, V. I.

AU - Vosmerikova, L. N.

AU - Vosmerikov, A. V.

PY - 2018/4/1

Y1 - 2018/4/1

N2 - 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.

AB - 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.

KW - active centers

KW - aggregates

KW - clusters

KW - crystals

KW - elementoaluminosilicate

KW - morphology

KW - zeolite

UR - http://www.scopus.com/inward/record.url?scp=85045074107&partnerID=8YFLogxK

U2 - 10.1134/S0036024418040349

DO - 10.1134/S0036024418040349

M3 - Article

AN - SCOPUS:85045074107

VL - 92

SP - 689

EP - 695

JO - Russian Journal of Physical Chemistry A

JF - Russian Journal of Physical Chemistry A

SN - 0036-0244

IS - 4

ER -