Solid-state synthesis of copper-containing zeolites: local atomic structure of catalytically active copper centers by means of XAS spectroscopy and DFT modeling

Abstract

Solid-state synthesis of copper-containing zeolites: local atomic structure of catalytically active copper centers by means of XAS spectroscopy and DFT modeling

Bdoyan K.E., Razdorov V.N., Ermakova A.M., Durymanov V.A., Avakyan L.A., Sukharina G.B., Pryadchenko V.V.

Incoming article date: 21.12.2018

Today, catalysts based on zeolites containing transition metal ions are being intensively developed, ensuring the selectivity of the reaction of direct oxidation of methane to methanol. In current work, the X-ray absorption spectroscopy complimented with the structural models obtained in frames of the density functional theory were used to study the dependence of the local atomic structure of copper centers in mordenite type zeolites synthesized by solid-phase ion exchange using CuCl and H-MOR, upon the annealing temperature at different stages of synthesis. The typical Cu – O interatomic distances and the corresponding coordination numbers are determined. The dependence of the fraction of copper ions on the zeolite on the annealing temperature was established.

Keywords: EXAFS, DFT, zeolites, solid-phase synthesis, methanol synthesis