Enhanced DeNO(x) Performance of CZ-xS Catalyst Prepared by Sol–Gel Method

A series of CZ-xS catalysts for deNO(x) were prepared by sol–gel method. The effects of preparation methods and the amount of sulfuric acid in the sol–gel preparation process on the performance of catalyst were investigated by means of X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), N₂ adsorption–desorption, NH₃-temperature programmed desorption (NH₃-TPD), H₂-temperature-programmed (H₂-TPR) and Scanning electron microscope/Energy Dispersive Spectrometer (SEM/EDS). The results showed that when the mass ratio of SO₄²⁻/ZrO₂ (CZ-0.4S catalyst) was 0.4, the catalytic performance of the catalyst prepared by sol–gel method was greatly improved compared with the sample prepared by coprecipitation + impregnation method. When the space velocity was 220,000 h⁻¹ and the reaction temperature was in range of 290–500 °C, the NO conversion was higher than 90% on CZ-0.4S catalyst. Its excellent denitrification performance was attributed to its larger acidity, higher Ce³⁺ content, more surface adsorbed oxygen and larger specific surface area.