CHARACTERIZATION OF TITANIA SURFACE-AREA IN TITANIA SILICA SCR CATALYSTS BY TEMPERATURE-PROGRAMMED REACTION OF 2-PROPANOL/

This work describes the adaptation of a temperature-programmed reactio n (TPRe) analysis to determine the effective titania surface area (ETS A) in mixed titania/silica catalysts used for the selective catalytic reduction of nitrogen oxides. Isopropanol is used as the probe molecul e. Since dehydration of the alcohol adsorbed on the titanyl and silano l groups occurs at two distinct temperatures, the exposed (or effectiv e) titania surface area can be measured through quantitation of evolve d propene over the titanyl,stoups via mass spectrometry. Relevance of the use of this technique in the evaluation of raw powders and finishe d monoliths prior to active metal impregnation is demonstrated through comparison of ETSA data to catalyst activity data with good results.