Correlating between physico-chemical properties and catalytic performance of tuned CeO2 in the catalytic oxidation of carbon black and propylene

Abstract

In this work, ceria with different Ce/CTACl ratios (R= 1.5, 6.5 & 13), an original sample prepared without any use of surfactant, and different ceria shapes (nano-cross, nano-cube, monodisperse spheres, nano-rod and nano-column) were synthesized and tested in the catalytic oxidation of carbon black and propylene. X-Ray diffraction results of all samples exhibited the typical pure cubic fluorite structure of CeO2. The monodisperse spheres shape is found to be the best catalyst among all shapes in the catalytic oxidation of propylene and carbon black which might refers to the fact of having the highest pore diameter (269 Å). Mesoporous ceria of R=6.5 exhibited the lowest temperature of propylene conversion which is mostly due to the fact of having the highest pore volume (0.3492 cm-3.g -1) and pore diameter (94 Å) among the other ratios. Thus, the high reactivity shown by the monodisperse spheres CeO2 and the ceria of ratio 6.5 is mainly referring to their high oxygen storage capacity (OSC) which is governed by some specific physicchemical properties that characterize the catalyst surface.