The incorporation of Me-histidine complexes in the structure of FAU-type zeolite: Characterization of the obtained materials

Abstract

L-histidine, a naturally occurring amino acid, was incorporated inside the supercages of FAU type zeolite in a form of Me-complex entity (Me = Cu(II), Zn(II), Fe(III)). The preparation was done either by ion-exchange procedure, or previously prepared Me-histidine complex was incorporated into the a cages of Y zeolite by occlusion. The preparation procedure was found to be a very important factor, as well as the amount of metal complex loaded on the zeolite. The characterization of obtained samples was performed using Diffuse Reflectance Ultraviolet-Visible Spectroscopy (DRUV-Vis), 13C MAS NMR and Infrared Spectroscopy (FTIR). It was noticed that 1-hostidine interacted with the zeolitic framework, and with the extra-framework cation, as well. The results obtained by TG-DSC/MAS technique, revealed that the thermal stability of incorporated histidine was increased, in comparison with that one of pure histidine.

Keywords

• metaloenzymes
• histidine
• transition metals
• Y-zeolite
• catalysis