Cesium as Alkali Promoter in Me-Cs (Me = Cu, Co, Fe)/ Al 2 O 3 Structured Catalysts for the Simultaneous Removal of Soot and NO x

Abstract

Structured catalysts for the simultaneous removal of soot and nitrogen oxides were prepared by means of coating cordierite monoliths with alumina-based suspensions containing Cu, Co or Fe and Cs as the catalytically active phase. Textural and chemical properties of the coated monoliths were determined by means of N2-physisorption, SEM and temperature programmed reduction. Their activity in the simultaneous removal of soot and NOx was assayed in a lab-scale installation, using a carbon black as diesel surrogate. Catalysts containing Cs exhibited significant activity in deNOx, however soot oxidation activity is poorly enhanced probably due to the low NO2 evolution, pointing to a different NOx adsorption mechanism in the present case, in comparison to previous observations on analogous K and Ba containing catalysts.