Redox reaction of nitric oxide and carbon monoxide over Fe2O3 and Co3O4 phases

Fe 2 O 3 and Co 3 O 4 phases are synthesized by the thermal treatment in an air-flow of hydrated salts based on Fe and Co. The materials are characterized by X-ray diffraction, energy dispersive spectroscopy, scanning electron microscopy, thermogravimetric analysis and surface area measurements. Fe 2 O 3 and Co 3 O 4 were tested for nitric oxide reduction with carbon monoxide in a 1:5 gas phase ratio and showed reaction rates in a range from 8.7 × 10 −11 to 5.9 × 10 −10 mol s −1 g −1 with an activation energy interval from 50.2 to 54.4 kJ mol −1 . Fe 2 O 3 and Co 3 O 4 achieved (100 and 98) % NO conversion with (96 and 80) % selectivity to N 2 at (275 and 350) °C. Fe 2 O 3 and Co 3 O 4 have the advantages such as facile synthesis, low-cost, good thermal stability, high activity and selective to N 2 . These results regarding activity and selectivity are better or similar to some catalysts based on noble metals (Rh, Pt and Pd) currently used for air pollutants control.