*2.1. The Monoliths*

In this work, semicircular commercial monoliths in SiC (Pirelli Ecotechnology (Arese, Italy), 150 cpsi) with a radius of 9 cm were used to assemble the DPF. The bare monoliths were preliminarily calcined at 1000 ◦C for 48 h. This thermal treatment allowed the formation of a SiO2 layer on SiC granules, increasing the adhesion of the active species over the filter even in the absence of a washcoat. Therefore, two filters with a total volume of about 3.5 L (D = 190 mm and L = 125 mm) were obtained by coupling four monoliths for each one, obtaining a Vfilter/engine displacement ratio = 1.3. The main features of the assembled bare filters are shown in Table S1.
