Experimental results of the investigations of the kinetic of selective
reduction of nitrogen oxides in the kinetic region (powder of catalys
t) and in the diffusion region (grains of catalyst) were described. It
has been shown, that for compositions of reactive mixtures conforming
to real exhaust gases, the rate of reaction can be described by the f
irst order equation in relation to nitrogen oxides. It has been stated
, that calculated parameters of kinetic equations, i.e. rate constants
and effective coefficients of diffusion have the values well-founded
physicochemically.