NO reduction and the formation of nitrogen compounds over a metal-supported three-way catalyst

• Published in: Fuel (Guildford) 1998, Vol.77 (9), p.1027-1031
• Main Authors: Takei, Masaru, Matsuda, Hitoki, Itaya, Yoshinori, Deguchi, Seiichi, Nakano, Koji, Nagahashi, Koji, Yoshino, Masato, Shibata, Juzo, Hasatani, Masanobu
• Format: Article
• Language: English
• Subjects: Air pollution caused by fuel industries; Applied sciences; catalytic chemical reaction; Energy; Energy. Thermal use of fuels; Exact sciences and technology; nitric oxide reduction; Pollution reduction; Stack gas and industrial effluent processing; three-way catalyst
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/S0016-2361(97)00288-3

The fundamental characteristics of NO reduction and the formation of nitrogen compounds such as N 2O, NH 3 and HCN were investigated on a metal-honeycomb-supported three-way catalyst. Experiments were carried out in a quartz glass tube reactor by flowing simulated gas mixtures in the NO/H 2/Ar, NO/CH 4/Ar and NO/CO/Ar systems. In the NO/H 2/Ar system, NO reduction began at the lowest temperature of all the systems examined. In any system, the conversion ratio of NO reduction was over 90% at gas temperature higher than 900 K. However, depending on temperature, NO reduction resulted in nitrogen-compound formation as NH 3 in the NO/H 2/Ar system, HCN in the NO/CH 4/Ar system, and N 2O in all systems. In particular, N 2O formation was dominant at relatively low temperature. The effect of the coexistence of the oxygen on NO reduction was also examined and a sufficient conversion was observed if the O 2 concentration was less than 1 vol%.