Transient surface processes of storage and conversion of NOx species on Pt-Me/Al2O3 catalysts (Me = Ba, Ce, Cu)

The transient reactivity and surface phenomena of storage and conversion of NOx species on Pt(1%)-Me/Al2O3 catalysts, where Me = Ba, Ce and Cu, were s tudied by the RWF (rectangular wavefront) method. The Me component has a re levant influence on the processes of surface storage and transformation. Th e reduction of NOx by propene in the presence of oxygen is promoted by addi ng Cu to a Pt/Al2O3 catalyst, while cerium promotes transient conversion of NO in the absence of propene, but inhibits the reduction of NOx in the pre sence of propene. Copper is suggested to be a promising element to add toge ther with Ba for new NOx storage-reduction catalysts due to its capacity to act both as a storage element and as promoter for NOx reduction.