Oxide Nanoparticles within a host microporous matrix: Polynuclear copper species in Cu-ZM5 and their role in the reduction of NO

The role of copper-oxide nanoparticles inside a host ZSM5 zeolite, identified by UV-Visible-NIR diffuse reflectance spectroscopy on the reactivity in NO reduction to N2 in the presence of propane/O2 or ammonia/O2 is discussed. These species lead to an enhancement in the rate of alkane depletion in the reduction of NO in the presence of propane/O2, whereas they cooperate with isolated ions at exchangeable sites in determining the overall catalytic behaviour in NO reduction in the presence of ammonia/O2. Also the stability of these species depends on the type of reductant.