Preparation of Ag/SAPO-34 zeolite photocatalyst

Abstract

In this work, the thermal stability of SAPO-34 was studied in order to propose a new experimental route to prepare a metal-loaded catalyst. In the literature, the crystalline collapse of SAPO-34 structure has been reported when these zeolites were exposed to thermal treatment. Preparation and characterization of Ag/SAPO-34 catalyst was realized by the initial incorporation of Ag instead of post-charging of this metal into the zeolite. Hydrothermal method was implemented followed by thermal treatment. Scanning electron microscopy, X-ray Diffraction, UV-Visible spectroscopy and Fourier transform-infrared spectroscopy techniques were employed in order to demonstrate the preparation of catalyst from the herein proposed method. These analyses were carried out to determine the characteristics of Ag/SAPO-34 structure, where Ag was impregnated during the hydrothermal synthesis of the zeolite followed by two different methods to reduce the Ag ions. Results showed that the sample of Ag/SAPO-34 reduced with hydrogen has activity in the visible region. Although the Ag/SAPO-34 was not tested for degrading a contaminant, this work showed a procedure to obtain a photocatalyst useful in the visible region opening the possibility for replacing TiO2 photocatalyst in wastewater treatment.