The deactivation of Ce/TiO2 catalyst for NH3-SCR reaction by alkali metals: TPD and DRIFT studies

The deactivation mechanism of alkali metals on the SCR catalyst of Ce/TiO2 was investigated by TPD and DRIFT studies. It could be found that the addition of Na or K on Ce/TiO2 catalyst would restrict the adsorption of NH3, accompanied by the generation of new sites for the adsorption of NOx species. But the new-absorbed NOx species were not active in the NH3-SCR reaction. The results of in situ DRIFT study indicated that the addition of Na and K did not change the SCR reaction mechanism, which was the combination of the Eley-Rideal and the Langmuir-Hinshelwood mechanisms. (C) 2016 Elsevier B.V. All rights reserved.