Modified Co3O4/ZrO2 catalysts for VOC emissions abatement.
Résumé
The catalytic activity study of cobalt oxides dispersed on different supports evidenced first the highest performances of zirconia based catalysts in the reaction of toluene oxidn. The influence of the presence of ethylenediamine (en) during the prepn. of Co/ZrO2 and the ZrO2 support modification by Y2O3 were then studied and compared with ref. catalyst prepd. conventionally by impregnation of ZrO2 with an aq. soln. of Co(NO3)2. Addn. of an aq. soln. of ethylenediamine to a cobalt nitrate soln. led to a strong increase on the catalytic activity of the activated solids in the toluene deep oxidn. as compared with the ref. catalyst. The best catalytic results were explained in terms of cobalt oxides dispersion but also in terms of Co-support interaction. The generated cobalt species were reducible at much lower temps. and then were more active in the toluene total oxidn. Finally an efficient catalyst for VOC oxidn. was produced combining the modifications of ZrO2 by yttrium and of the precursor.