On the redox nature of ceria-zirconia mixed nanocatalysts and its effect on catalytic wet peroxide oxidation of chlorinated organic pollutants

The potential application of ZrxCe1-xO2 (x: 1, 0.75, 0.5, 0.25, 0) nanocomposites in the oxidation of chlorinated phenolic compounds was studied with respect to Catalytic We Peroxide oxidation of 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4-dichlorophenoxy acetic acid (2,4-D) was experimented in presence of aqueous hydrogen peroxide as oxidant. Zirconium doping on nanoceria lattice increased its catalytic activity towards Wet Peroxide Oxidation of the target pollutants. 4-CP (500 mg/L) was degraded with 14.9% TOC and 45.8% COD removal after 75 min at 70 degrees C using Zr0.75Ce0.25O2 catalyst 2,4-DCP (250 mg/L) conversion with 22.5% TOC and 52.8% COD removal was observed at 75 min over Zr0.5Ce0.5O2 catalyst 100% catalytic oxidative conversion of 2,4-D (250 mg/L) with 23.68% Total Organic Carbon (TOC) and 47.80% Chemical Oxygen Demand (COD) removal was achieved at 70 degrees C at 90 min. Temperature Programmed Reduction (TPR) analysis indicated that the reducing capacity of ceria increased on zirconium doping. The catalysts were stable and reusable upto six successive runs as demonstrated by X-ray diffraction (XRD) and surface area measurements.