Applied Catalysis A: General, Vol.568, 64-75, 2018
Nickel loaded zeolites FAU and MFI: Characterization and activity in water-phase hydrodehalogenation of TCE
This work was aimed to investigate the catalytic properties of nickel loaded zeolites Y and ZSM-5 as the catalysts in hydrodechlorination of trichloroethylene (TCE HDC) in the aqueous phase. Both acidic forms of the zeolites and Ni loaded zeolites were thoroughly characterized with respect to their structural (XRD), textural (low temperature nitrogen sorption, STEM) and acidic/redox properties (IR, XPS, EPR spectroscopies). The studies showed the significant impact of acidic properties of the zeolitic support used as well as the framework geometry and the pore distribution within zeolite grains on the catalytic behaviour of zeolitic materials in the removal of TCE. IR studies of hydrodechlorination of trichloroethylene clearly showed the concurrent participation of both nickel and acid active sites in TCE HDC reaction. The activity of the Ni loaded catalysts increased when reducing the number of acid sites in zeolite catalysts, the centres responsible for carbonaceous deposits formation and finally leading to the catalysts deactivation. Nickel in the form of small (similar to 1-8 nm) and uniformly dispersed nanoparticles was found to be very active in the purification of water from TCE in batch conditions.