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H. Hamada, Y. Kintaichi, M. Tabata, M. Sasaki, and T. Ito
[Sekiyu Gakkaishi, Vol.36, p.149, 1993]
The characteristics of H-zeolite and alumina catalysts for selective reduction of NO by hydrocarbons were investigated. High NO conversions to N_{2} at relatively high temperature and low gas space velocity and excellent selectivity were obtained with these catalysts compared to Cu-ZSM-5. The activities of these catalysts were found to be related to their solid acidity, and they were effective for NO reduction within certain temperature ranges. Further, oxygen promoted NO reduction at low temperature. Investigations of alumina-catalyzed NO reduction revealed that CO and H_{2} did not reduce NO, and that the efficiency of NO reduction at low temperature increased in the order of paraffins ļ olefins ļ alcohols. The NO conversion over alumina at low temperature and high space velocity increased by having transition metals such as cobalt supported on the alumina. The oxidation of NO to NO_{2} was considered to be an important step in the overall selective reduction of NO over H-zeolites and alumina.