Removal of NOx: Part I. Sorption/desorption processes on barium aluminate

NOx adsorption/desorption capacities of barium aluminates were measured und er representative exhaust gas mixture at temperatures below 550 degrees C. The solid doped with Pt or not, exhibits good NO2 sorption capacities with a reversible adsorption to desorption process. With bulk BaO, desorption wa s observed at high temperature. The different behaviour between the two cat alysts is explained by the fact that strongly bonded carbonates are formed on bulk BaO while they do not exist on barium aluminate, therefore allowing the formation of nitrates which can be decomposed by a thermal process. SO 2 poisoning was also studied. (C) 1998 Elsevier Science B.V. All rights res erved.