In this work, a kinetic study of the selective catalytic reduction of NO with NH3 has been carried out in an effort to analyze the effects of the gas composition (NO, NH3, and O-2 partial pressures) and temperature (125-175 degreesC) on the catalytic activity of vanadium oxide supported on carbon-ceramic cellular monoliths. The experimental results were analyzed using a power-law expression. On the basis of the values of the coefficients of the power-law expression and the catalyst behavior in the presence of water vapor, it can be concluded that the reaction proceeds via a mechanism in which NO reacts from the adsorbed phase with adsorbed NH3. A detailed kinetic expression derived from this mechanism fits the experimental data accurately, thereby validating the mechanism proposed.