Adsorption of NO and NH3 over CuO/γ-Al2O3 catalyst

• Published in: Journal of Central South University of Technology. Science & technology of mining and metallurgy 2011-12, Vol.18 (6), p.1883-1890
• Main Authors: Zhao, Qing-sen, Sun, Lu-shi, Liu, Yong, Su, Sheng, Xiang, Jun, Hu, Song
• Format: Article
• Language: English
• Subjects: Engineering; Metallic Materials
• ISSN: 1005-9784; 1993-0666
• DOI: 10.1007/s11771-011-0918-9

The selective catalytic reduction reaction belongs to the gas-solid multiphase reaction, and the adsorption of NH 3 and NO on CuO/ γ -Al 2 O 3 catalysts plays an important role in the reaction. Performance of the CuO/ γ -Al 2 O 3 catalysts was explored in a fixed bed adsorption system. The catalysts maintain nearly 100% NO conversion efficiency at 350 °C. Comprehensive tests were carried out to study the adsorption behavior of NH 3 and NO over the catalysts. The desorption experiments prove that NH 3 and NO are adsorbed on CuO/ γ -Al 2 O 3 catalysts. The adsorption behaviors of NH 3 and NO were also studied with the in-situ diffusion reflectance infrared Fourier transform spectroscopy methods. The results show that NH 3 could be strongly adsorbed on the catalysts, resulting in coordinated NH 3 and NH 4 + NO adsorption leads to the formation of bridging bidentate nitrate, chelating bidentate nitrate, and chelating nitro. The interaction of NH 3 and NO molecules with the Cu 2+ present on the CuAl 2 O 4 (100) surface was investigated by using a periodic density functional theory. The results show that the adsorption of all the molecules on the Cu 2+ site is energetically favorable, whereas NO bound is stronger than that of NH 3 with the adsorption site, and key information about the structural and energetic properties was also addressed.