Lanthanide doped V2O5/Al2O3 catalysts: Structure-activity relationship in the SCR of NOx

The structure of lanthanide-doped (La, Sm, and Ce) V2O5/Al2O3 catalysts for the Selective Catalytic Reduction (SCR) of NOx with NH3 in the presence of O-2 have been studied by means of XRD, S-BET, XAS, UV-vis, XPS, and TPR te chniques. As function of the vanadium loading and lanthanide dopant used, a n alteration of the electronic density of support cations and supported van adium ions is detected. The activation energy of the catalysts in the SCR r eaction is directly related with the Lewis acidity of the vanadium species, in such a way that the higher the ionicity of the V-O bond, the higher the specific activity of the catalysts.