Abstract

The selective catalytic oxidation (SCO) of gas phase ammonia (NH₃) to nitrogen and water has been proposed as an effective ammonia removal process. This study reports that the oxidation of NH₃ with oxygen to form N₂ was investigated by SCO using a Pt-Rh complex catalyst that was synthesized by the incipient wetness impregnation process. The catalysts were performed using fluorescent spectroscopy (FS) combined with UV-Vis absorption, cyclic voltammetry (CV), linear sweep voltammograms (LSV), zeta potentialmeasurements and dynamic light-scattering (DLS). The findings show that the ammonia removal by catalytic oxidation over the Pt-Rh complex catalyst was nearly 95% at a temperature of 623K and an oxygen content of 4%. N₂ was the main end product of the NH₃-SCO process. FS have been applied to evaluate the catalyst yields with fluorescent peaks of 270 and 390 nm at room temperature. These results suggest that FS was proven to be an appropriate and effective method to characterize the Rh clusters that enhance their intrinsic emission from Pt-Rh complex catalyst in catalytic treatment systems. The CV and LSV reversible redox ability may explain the significant activity of the catalysts.

Key words: Selective catalytic oxidation (SCO), ammonia (NH₃), Pt-Rh complex catalyst, fluorescent spectroscopy (FS), cyclic voltammetry (CV), linear sweep voltammograms (LSV).