BIOMORPHIC SYNTHESIS OF COBALT OXIDE AND CERIA MICROFIBERS. THEIR APPLICATION IN DIESEL SOOT OXIDATION.

M.A. STEGMAYER; V.G. MILT; E.E. MIRÓ

Congreso; XXVII Congreso Iberoamericano de Catálisis, CICAT 2020; 2020

Microfibers of CeO2, Co3O4 and Co,Ce were synthesized by using commercial cotton fibers as biotemplates. After the combustion of the organic material, ceramic hollow microfibers with the morphology of the cotton fibers were obtained. For the synthesis of Co,Ce mixed fibers two ways of incorporating cobalt were studied: wet impregnation and in situ synthesis. Ceria fibers were active for diesel soot combustion as demonstrated in Temperature-Programmed Oxidation (TPO) experiments, in which a maximum combustion rate value at TM=420 °C was obtained. While cobalt fibers were even more active (TM=365 °C), Co,Ce fibers resulted in intermediate activity (TM=380 °C) irrespective of the way in which cobalt was incorporated. The addition of 2 wt.% Co to the fibers improved the catalytic activity with respect to the bare ceria fibers, but no differences in activity were observed by increasing the percentage of Co to 12 wt.%. From XPS characterization, it isspeculated that the catalytic improvement could be related to the greater proportion of chemisorbed labile oxygen.