The selective catalytic reduction (SCR) of NO was studied over alumina-based catalysts. The experimental data showed that the peak NO conversion and the temperature range where each catalyst exhibits its highest activity depend on the impregnated metal. Kinetic studies were carried out to estimate the apparent order of reaction with respect to the involved gases and the apparent activation energies, The catalytic activity of the alumina-based catalysts was also tested in a fixed-bed reactor unit under various reaction conditions. A mathematical model was applied to reproduce the experimental data using the experimentally determined reaction rate expression. The model predictions were in agreement with the concentrations measured at the exit of the fixed-bed reactor, though no arbitrarily chosen parameters were used in the application of the mathematical model.