Catalyzed Diesel Particulate Filter (cDPF)

Since about 2005, particulate filters have been generally used with modern diesel engines to remove diesel particulate mass emissions (PM) while significantly reducing the emitted particulate number (PN).

The most effective type is the so called wall-flow filter. Particulate matter is removed from the exhaust by physical filtration using a honeycomb structure similar to an emissions catalyst substrate but with the channels blocked at alternate ends. The exhaust gas is thus forced to flow through the walls between the channels and the particulate matter is deposited as a soot cake on the walls. Such filters are made of ceramic honeycomb materials (cordierite, silicon carbide or aluminium titanate).

Ceramic wall flow filters almost completely remove the carbon particulates over a wide range of engine operating conditions. Since the continuous flow of soot into the filter would eventually block it, it is necessary to 'regenerate' the filtration properties of the filter by burning off the collected particulate on a regular basis. Therefore, the exhaust temperature in Diesel passenger car applications is frequently increased until collected soot is burned off. In order to reduce the burn-off temperature, the filter is usually coated with an oxidation function.

This catalytic coating also contributes to the reduction of CO and HC due to oxidation and in addition it can form NO2 to support the functionality of an SCR catalyst.


      Umicore uses certain monitoring and tracking technologies such as cookies. These technologies are used in order to maintain, provide and improve our services on an ongoing basis, and in order to provide our web visitors with a better experience.

      By clicking on the "Accept all" button you agree to the use of these cookies while using the website. For further information regarding how we use cookies and other tracking technologies, please see section 11 of our website privacy notice

          Necessary cookies are essential and help you navigate our website. This helps to support security and basic functionality and are necessary for the proper operation of our website, so if you block these cookies we cannot guarantee your use or the security during your visit.

          Cookies that help us to understand the behaviour of users of our website. This allows us to continuously improve our website to provide the best information in support of our project aims. These cookies also help us understand the effectiveness of our website. For instance these cookies tell us which pages visitors go to most often and if they get error messages from web pages.

          Cookies that deliver content to you based on your interests, which are assumed from your browsing history. Most Targeting Cookies track users via their IP address and, thus, may collect some Personal Data. Personal Data collected by Targeting Cookies may be shared with third parties, such as advertisers.