The Poisoning Effect of Na Doping over Mn-Ce/TiO2 Catalyst for Low-Temperature Selective Catalytic Reduction of NO by NH3

Sodium carbonate (Na2CO3), sodium nitrate (NaNO3), and sodium chloride (NaCl) were chosen as the precursors to prepare the Na salts deposited Mn-Ce/TiO2 catalysts through an impregnation method. The influence of Na on the performance of the Mn-Ce/TiO2 catalyst for low-temperature selective catalytic reduction of NOx by NH3 was investigated. Experimental results showed that Na salts had negative effects on the activity of Mn-Ce/TiO2 and the precursors of Na salts also affected the catalytic activity. The precursor Na2CO3 had a greater impact on the catalytic activity, while NaNO3 had minimal effect. The characterization results indicated that the significant changes in physical and chemical properties of Mn-Ce/TiO2 were observed after Na was doped on the catalysts. The significant decreases in surface areas and NH3 adsorption amounts were observed after Na was doped on the catalysts, which could be considered as the main reasons for the deactivation of Na deposited Mn-Ce/TiO2.