Catalytic Reduction of NO by CO over Promoted Cu₃Ce0.2Al0.8 Composite Oxides Derived from Hydrotalcite-Like Compounds

Catalytic reduction of NO by CO has been studied over a battery of Cu 3 Ce x Al (1– x ) composite oxide catalysts prepared by coprecipitation method. The solids were further characterized by X-ray diffraction, laser Raman spectra, N 2 -physisorption (Brunauer–Emmet–Teller (BET)), H 2 -temperature-programmed reduction, inductively coupled plasma atomic emission spectroscopy, X-ray photoelectron spectroscopy, and in situ diffuse reflectance infrared Fourier transform spectroscopy techniques. The assessment on the catalytic properties were conducted with the NO + CO model reaction. The influences of Cu and different ratios of Ce and Al on the catalytic performance have been investigated. When the ratio of Ce and Al was 1:4, this sample possessed the best catalytic properties, which was exactly derived from hydrotalcite-like compounds. The introduction of a few cerium species (Cu/Ce = 15:1) in the structure improved the activity/selectivity toward selective catalytic reduction of NO by lowering the temperature of carbon monoxide oxidation.