PREPARATION OF CATALYST BASED ON Ce-Pr FOR COMBUSTION OF n-HEXANE

Abstract

Catalysts based on Ce-Pr mixed oxides, , were prepared by coprecipitation (x ranged from 0,1 to 0,9) for combustion of n-hexane. For comparison purposes, the pure simple oxides were also prepared. Catalysts were characterized by sorption of N and X-ray 2 diffraction (XRD). The analysis of adsorption isotherms of catalysts showed profiles of type 2 IV, with specific surfaces ranging from 9,1 to 62,3 m /g, with the prevalence of mesoporosity. The X-ray diffractogram patterns for pure and mixed oxide catalysts show the majority presence of stable fluorite phase. The introduction of Pr in mixed oxide composition maintains the crystal structure of fluorite-like type. The catalytic tests were carried out in a fixed bed reactor with a starting concentration of n-hexane of 2000 ppm and weight hourly space -1 velocity (WHSV) of 80 h . The total combustion temperatures for mixed oxides catalysts were in the range of 356 to 437 °C. The oxide showed higher specific rate (evaluated per hour, gram of catalyst considering the specific surface) than the other mixed oxides and pure simple oxides as a result of a higher value of surface area obtained.