For environmental protection, the suppression of automotive exhausts such as nitrogen oxides and carbon monoxide is very important. These gases are potential health hazards and green house gases. Hence this concern triggered the need for stringent environmental regulations which resulted in the introduction of catalytic devices in automobiles. In this book, a novel approach has been developed wherein the noble metal nanocatalysts have been incorporated on ceramic nanofibers by the electrospinning process. The catalysts on ceramic nanofibers increase the overall exposed catalyst area and simultaneously immobilize the catalyst to minimize catalyst loss. A small amount of the catalyst incorporated into ceramic nanofibers was mixed with microfibers to fabricate a filter disk by vacuum molding. This filter disk termed as ‘catalytic filter’is a combination of catalytic elements and filter. The catalyzed ceramic nanofiber augmented microfiber filter media can be used for two applications: reduction of NOx and oxidation of CO and for enhanced particulate removal.