The influence of molar ratios of Ce/Zr on the selective catalytic reduction of NO with NH over FeO-WO/CeZrO (0 ≤ x ≤ 1) monolith catalyst.

A series of CeZrO (0 ≤ x ≤ 1) with different molar ratios of Ce/Zr were syhthesized via coprecipitation method, and FeO-WO/CeZrO monolithic catalysts were prepared for selective catalytic reduction of nitrogen oxides by ammonia (NH-SCR). The structural properties and redox behavior of the catalysts were comprehensively characterized by N physisorption, X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), H-temperature programmed reduction (H-TPR) and activity measurement for NH-SCR. The results showed that the NH-SCR activities of the catalysts were gradually enhanced by increasing the molar ratios of Ce/Zr, especially the low-temperature catalytic activity and the reaction temperature window. FeO-WO/CeZrO monolithic catalyst presented the best NH-SCR activity among the investigated catalysts, more than 90 % NO could be removed in the temperature range of 247-454 °C on the catalyst under the gas hourly space velocities of 30,000 h. And it always held more than 99 % N selectivity and less than 20 ppm (1 ppm = 10 L/L ) NO generation concentration between 200 and 500 °C, the catalyst also displayed its strong resistance of HO and SO. Good textural and structural properties, more surface Fe, Ce and active oxygen were together contributed to the excellent NH-SCR performance of FeO-WO/CeZrO catalyst. [ABSTRACT FROM AUTHOR]