No abstract

No abstract

No abstract

The influence of the combustion products of different lubrication oil additives and impurities in fuel or urea solution on the activity and selectivity of V 2 O 5 /WO 3 -TiO 2 catalysts in the selective catalytic reduction (SCR) of nitrogen oxides by ammonia was investigated. Focusing on the deactivation by calcium, phosphate, and potassium, the DeNO x activity followed the order K)Ca>PO 4 . This trend was investigated on the structural level of the catalyst by means of temperature programmed desorption of ammonia (NH 3 -TPD) and a DRIFT characterization of the adsorbed ammonia species. The results suggest that the studied elements strongly reduce the acidity of the SCR catalyst in the order K ) Ca>PO 4 by mainly affecting the Brønsted acidity of the surface.