Synthesis and physicochemical characterization of nanostructured CeO2/clinoptilolite for catalytic total oxidation of xylene at low temperature

A series of nanostructured CeO2/Clinoptilolite catalysts with different loadings of ceria were prepared by redox reaction followed by wet impregnation method and tested for oxidation of xylene. The catalysts were characterized by XRD, FESEM, BET, FTIR, and TG-DTG analysis. XRD data confirmed the formation of CeO2 as the crystalline phase with an average crystallite size of about 11.6 nm for three ceria loading of 10, 20, and 30%. FESEM and size distribution analyses showed that nanocatalysts have nanometric particles with an average size of 37.46 nm. Specific surface analysis revealed that the synthesized nanocatalysts had large enough surface area for catalytic oxidation of p-xylene. Furthermore, the results showed that the catalytic performance of the supported CeO2 catalysts was much higher than that of treated clinoptilolite, in particular, CeO2 (30%)/Clinoptilolite exhibited the highest conversion, 98% at 350 degrees C. It is observed that increasing both the xylene concentration and GHSV results in decreasing of the xylene conversion; however, even at higher concentrations of xylene (3000 ppm), the nanostructured catalyst has still enough destruction ability to reduce the pollutant. A simplified reaction mechanism was proposed with respect to the behavior of adsorbed species on the catalyst surface to clarify the path through which the reaction components interact with each other. (c) 2012 American Institute of Chemical Engineers Environ Prog, 32: 587-597, 2013