Multifunctional catalyst for maximizing NOx oxidation/storage/reduction: The role of the different active sites

A multifunctional catalyst/storage material has been prepared to maximize NO x removal. This material is based on mixed oxides derived from modified layered double hydrotalcites (LDH). A cobalt catalytic function oxidizes the NO to NO2. The NO2 is stored as nitrate in the basic sites of the material. The basic properties of the Co/Mg/Al mixed oxide derived from LDH were enhanced by doping with sodium, improving the storage capacity of the catalyst. Finally, the introduction of vanadium sites, enables the reduction–decomposition of the nitrates. This multisite catalyst/storage material results in a well equilibrate formulation that maximizes catalyst conversion and regenerability.