Microwave regenerated catalytic foam: A more effective way for PM reduction

The effect of microwave irradiation on the regeneration of soot-loaded uncatalytic and catalytic ceramic foam filters was studied for two different catalytic filter formulations. Combining dielectric permittivity and catalytic activity of the foam filter components with microwave absorbing properties of soot allowed a more effective filter regeneration. In the presence of microwaves, the iron based catalysts, not active towards soot oxidation during conventional heating, reduced the onset temperature, and enhanced the soot oxidation rate. In the case of Cu/V/K/Cl catalyst modified foam, microwaves acted together with the intrinsically very high soot oxidation activity, giving onset temperature of 530 K, higher selectivity to CO 2, higher soot combustion rate, and 35% larger energy recovering with respect to the unmodified foam.