Solvothermal synthesis of well-designed ceria-tin-titanium catalysts with enhanced catalytic performance for wide temperature NH3-SCR reaction

Abstract Ternary mixed ceria-titanium catalysts doping tin were synthesized by a solvothermal method and applied to selective catalytic reduction (SCR) of NO with NH3. The Sn doping catalyst showed better low-temperature activity compared with unmodified catalyst, which exhibited an extraordinarily wide operation window ranging from 180 to 460 °C and better the tolerance of H2O or SO2. Powder X-ray diffraction (XRD), laser Raman spectroscopy (Raman), fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), BET surface area by N2-adsorption-desorption, hydrogen temperature-programmed reduction (H2-TPR), ammonia temperature-programmed desorption (NH3-TPD) were performed to study the structure, redox ability and surface acidity for the CeSnTiOx catalyst. Notably, the addition of Sn could prominently modify and optimize the structure of mixed metal oxides. Meanwhile, it was verified that synergistic interaction between of Ce and Sn surprisingly produced, and crystal defects, oxygen vacancies, acid sites as well as the specific surface areas evidently increased. In addition, the uniform pore channel was also beneficial to NH3-SCR. Especially, the electron interaction between Sn and Ce in reaction could greatly improve the SCR performance and H2O/SO2 durability.