Diesel particulate filters (DPF’s) have been a standard component in the exhaust after treatment for many years for passenger cars, trucks and buses globally.
The filter is regenerated either passively (NO2 oxidation) or actively (fuel injection). Catalytic materials are coated onto the filter to lower the temperature of soot oxidation and to promote NO2 formation.
Gasoline particulate filters (GPF) are a more recent development. Although low in mass, GDI (Gasoline Direct Injection) engines emit a large number of very small (hazardous) soot particles.
Any coating can lead to an increase in back pressure (reduced fuel economy and peak power, etc.)