Valorization of Recycled Honeycombs from Exhausted TWCs by Means of Their Use as a Support of MnOx Catalysts for Acetone Combustion

Exhausted TWCs subjected to chemical/thermal treatments were used as a support of MnOx catalysts for the total combustion of acetone. The so-prepared new devices were characterized by using adherence tests, elemental and thermal analyses, XRD, N-2 physisorption, and SEM-EDS. Incorporation of only 2.6 wt.% of the active phase (Mn2O3 and Mn3O4) to the recycled honeycomb considerably improved the catalytic response, achieving at 250 degrees C a 60% increase in acetone conversion with respect to the spent autocatalyst. The following procedure is proposed as a simple way to provide the TWC devoid of noble metals a second life in the VOCs' oxidation field.