摘要
Ptx2013;Bax2013;Alub>2ub>Oub>3ub> active and selective for NOub>xub> storage and selective reduction to Nub>2ub> has been prepared and tested. Characterization of the parent Alub>2ub>Oub>3ub>, Ptx2013;Alub>2ub>Oub>3ub> and Bax2013;Alub>2ub>Oub>3ub> materials, as well as of Ptx2013;Bax2013;Alub>2ub>Oub>3ub> catalyst in the oxidized, reduced and sulphated state has been performed by FT-IR spectroscopy of low-temperature adsorbed carbon monoxide and of adsorbed acetonitrile. XRD, TEM and XPS analyses have also been performed. Evidence for the predominance of Ba species, which are highly dispersed on the alumina support surface, and may be carbonated or sulphated, has been provided. Competitive interaction of Pt and Ba species with the surface sites of alumina has also been found.