Reduction of nitric oxide by carbon monoxide over NiO, CuO, and ZnO catalysts

NiO, CuO and ZnO catalysts were synthesized by thermal decomposition using Ni, Cu, and Zn salts as precursors. The materials were characterized by X-ray diffraction, energy dispersive spectroscopy, scanning electron microscopy, crystal size and surface area measurements. The catalysts were tested for NO reduction with CO. The NO reduction rate was in the range of (4.3 × 10−12–1.3 × 10−8) mol s−1 g−1, and its activation energy was within an interval of (41.8–83.7) kJ mol−1 K−1. The catalysts showed the following decreasing order of activity: CuO > NiO > ZnO. Catalyst CuO is a better catalyst than NiO and ZnO and achieved 100 % NO conversion at 275 °C with 94 % selectivity to N2.