Alkaline- and alkaline-earth oxides based Lean NOx Traps: Effect of the storage component on the catalytic reactivity

Combined Fixed‐Bed Reactor and In Situ DRIFTS Tests of NO Adsorption on a NOx Storage‐Reduction System Catalyst

“…The NSCs of our catalyst are in good agreement with the result obtained by Castoldi et al with similar catalysts containing 20 wt % of Ba [27]. During this step, both desorbed NO x amounts and adsorbed species changed.…”

Investigation of NO2 and NO interaction with an Fe-ZSM-5 catalyst by transient response methods and chemical trapping techniques

“…8C we observe a main band around 1100 cm À1 that can be assigned to m N-O modes of Ba nitrites [36,37]. The band at 1220 cm À1 is representative of nitrite adspecies and, more precisely, of the m asym of NO 2 associated with ionic nitrites [24,[34][35][36]. The most interesting feature is represented by the peak at 1270 cm À1 , which can be assigned to free NO 2 À [8,34,38,39].…”

“…In particular, in Fig. 8C we observe a main band around 1100 cm À1 that can be assigned to m N-O modes of Ba nitrites [36,37]. The band at 1220 cm À1 is representative of nitrite adspecies and, more precisely, of the m asym of NO 2 associated with ionic nitrites [24,[34][35][36].…”

The optimal volume of a combined system of LNT and SCR catalysts

“…Since diesel engines operate only under lean conditions, the NOx emitted under these conditions have to be adsorbed on the adsorbent (Ba, K) [2,7] before being reduced by the reductants (CO, HC, H 2 ) that are generated during the short-rich operations of the engines [8][9][10]. Several groups of engineers have already evaluated the performance of a combined system of LNT + SCR with light-duty diesel engines [11][12][13][14][15]. The LNT catalyst was reported in those studies to remove NOx but also produce some NH 3 during rich operation [12,15].…”