Effects of doping zirconium on Ti-Ce-O_x catalytic complex oxides for selective catalytic reduction of NO

A series of Ti-Ce-Zr-O_x catalytic complex oxides were prepared by the chemical blend. Catalytic activity of Ti-Ce-Zr-O_x complex catalysts for selective catalytic reduction of NO with NH₃ (NH₃-selective catalytic reduction (SCR)) was studied, and effects of doping zirconium on the SCR of NO with ammonia were investigated. Crystal form, pore structure, crystalline morphology, chemical composition, and solid acidity of the catalysts were characterized by the X-ray diffraction, N₂ physical adsorption, scanning electron microscopy, energy spectrum analysis, and NH₃-temperature programmed desorption. Results show that when mole ratios n(NH₃):n(NO)=1:1, gas hourly space velocity is 5000/h, TiCe_0.1Zr_0.1O_2.4 complex catalysts have high activity in 200-350°C in the process of NH₃-SCR of NO and the highest activity can reach 92.70%. Compared with Ti-Ce-O_x catalytic complex oxides, doping zirconium can refine grain size, promote crystal defects, enhance solid acidity of Ti-Ce-Zr-O_x composite catalysts, and widen the catalytic active zone to the low temperature zone of about 50°C, and the highest NO conversion at 300°C is increased by 16.67%.