Spatially Resolved Measurements of HNCO Hydrolysis over SCR Catalysts

In order to understand deposit formation during urea selective catalytic reduction (SCR) resulting from isocyanic acid (HNCO) formation, the present study investigates the potential of HNCO hydrolysis by spatially resolved gas phase concentration profiles along a single catalyst channel of commercial Cu-zeolite and V-based SCR catalysts. The spatially resolved profiles, obtained in a special hot gas test rig via capillary technique, provide information on reaction rates of HNCO hydrolysis, NH$_3$ adsorption and NO conversion, hereby revealing a better performance of the standard V-based catalyst regarding the HNCO hydrolysis, which is attributed to the TiO$_2$ support.