Catalytic removal of trichloroethylene from water over palladium loaded microporous and hierarchical zeolites

The work was aimed to investigate the catalytic properties of Pd- containing ZSM-5 zeolites in hydrodechlorination of trichloroethylene (TCE HDC) in aqueous phase. Conventional purely microporous zeolite ZSM-5 and its mesostructured analogue obtained by alkaline leaching were used as the supports for palladium moieties. The resulting materials were subjected to chemical analysis, XRD characterization, CO chemisorption, and spectroscopic investigation (XPS and FTIR) and, then, used as the catalysts in removal of trichloroethylene from drinking water. The studies have shown clearly that catalytic performance of palladium loaded materials depended on acidic and textural properties of zeolites, which influenced both noble metal dispersion and Pd-0/Pd2+ ratio. In a series of the zeolite catalysts the best results were obtained for palladium deposited on desilicated form of ZSM-5. Palladium in the form of uniformly dispersed species, containing large amount of Pd-0 species was found to be significantly active in TCE HDC. (C) 2015 Elsevier B.V. All rights reserved.