Gold and gold-iron modified zeolites-Towards the adsorptive deodourisation

Zeolites exhibiting different structures (Y, Beta, and ZSM-5) were modified with gold and iron and applied for odour adsorption from the air containing dibutyl sulphide (Bu2S) used as a representative odour producing compound. The structure of the zeolites used determines the rate of adsorption (higher on Y type zeolites and smaller on two other zeolites), whereas hydrophilicity affects the selectivity towards Bu2S adsorption increasing in the order: Y < Beta < ZSM-5. For the same zeolite structure, Bu2S adsorption selectivity depends on the total acidity of zeolites which increases after iron modification. The texture and surface properties of the modified zeolites were studied by XRD, XPS, UV-vis, TEM, pyridine adsorption and FTIR, test reactions (acetonylacetone cyclisation, isopropanol decomposition).