Efficient NO/sub x/ removal using silent discharges and TiO/sub 2/ photocatalyst simultaneously

Summary form only given, as follows. The emission of NO/sub x/ from motor vehicles and so on has become a serious problem for the environment. The application of the combination of electric discharges and TiO/sub 2/ as a photocatalyst for the purification of air has been intensively studied. When the UV light shorter than 380 nm is irradiated on Anatase type TiO/sub 2/, a pair of an electron and hole is produced, which react with water or oxygen molecules and contribute to the radical production such as OH, then radicals accelerate the NO removal process. In N/sub 2/ gas discharges, the light emission from the second positive band of N/sub 2/ is quite strong and the light may excite TiO/sub 2/ photocatalyst. It has been shown that NOx is effectively removed using the TiO/sub 2/ filled packed bed discharge reactor with an H/sub 2/O/sub 2/ injector. Instead of using the packed bed reactor, in this study TiO/sub 2/ photocatalyst is coated on the inner surface of a reactor by the sol-gel method to expand the passageway of the flue gas hoping to process the gas on a larger scale.