Abstract
Presence of metallic Pt clusters highly enhances catalytic activity of iron ferrierite in N2O decomposition, even at low Pt loading (Pt/Al > 0.003). Platinum (II) cations in ferrierite are inactive; only some low activity appears with pre-reduced samples.
The behavior of bimetallic Pt,Fe-ferrierites samples is strongly dependent on the sequence of introduction of platinum and iron ions into the ferrierite. This sequence does not affect cationic state of iron ions, however, it changes the state of platinum; metallic Pt clusters are formed in samples where platinum was introduced as the first component.
Formation of Pt(0) clusters has been assigned to reduction of Pt ions by the decomposing acetylacetone in solution used for the ion exchange of iron ions. The presence of Pt(0) in iron ferrierite samples changes the composition of the products of decomposition of the surface NOx species formed during the decomposition of nitrous oxide.
It decreases the fraction of nitrogen dioxide and increases that of nitric oxide in the desorbing products.