Promoting mechanism of SO2 resistance performance by anatase TiO2 {0 0 1} facets on Mn-Ce/TiO2 catalysts during NH3-SCR reaction

Abstract

Anatase TiO2 with {001} facets (TiO2-NS) exposed and anatase TiO2 with {101} facets (TiO2-NP) exposed as carrier were used to prepare Mn-Ce/TiO2-NS and Mn-Ce/TiO2-NP catalysts, separately. The Mn-Ce/TiO2-NS catalyst still had a high specific surface area after the SO2 resistance test, which was attributed to the inhibition of the formation of ammonium bisulfate and ammonium sulfate. Additionally, anatase TiO2 {001} surface could effectively inhibit the sulfation of active ingredients, which was owing to the five-coordinated titanium atoms (Ti5c) and two-coordinated oxygen atoms on the anatase TiO2 {001} facets could preferentially react with SO2 to avoid deactivation of active sites after the poisoning experiment. Thus, the Mn-Ce/TiO2-NS catalyst had excellent resistance to SO2 in the poisoning test, indicating that it has great application prospects as a low-temperature SCR catalyst.