Urea-SCR Catalysts with Improved Low Temperature Activity

Urea-SCR systems have become one effective method for meeting the ever tightening NOx emission control regulations for diesel engines. Higher activity of SCR catalysts in the low temperature region is crucial for meeting emission regulations and improving fuel economy. Some of the new catalytic components in the literature have shown good low temperature SCR activity, but they have not been fully confirmed to be durable enough for mobile applications. Fe-zeolite has been widely used in mobile applications due to its wide operating temperature window, but after exposure to large amounts of HCs at low temperatures, it is easily deactivated. We developed new SCR catalysts with improved low temperature activity and improved durability against HC fouling and thermal sintering by combining OSC (oxygen storage component) with Fe-zeolite.