The application of numerical simulations of temperature-programmed reaction and desorption (TPRD) spectra as a means of supporting mechanistic studies of surface reactions is demonstrated through two simple examples: the chemistry of ethene hydrogenation and the chemistry of methyl moieties co-adsorbed with hydrogen atoms. Where possible, literature kinetic parameters have been employed in the simulations. Where no parameters exist, preliminary estimates of the kinetic parameters were systematically modified until a visual agreement between the empirical TPRD spectra and the numerical simulations was obtained. In this way, these simulations have permitted a preliminary determination of the activation energies and pre-exponential factors for a number of the reaction steps in the chemistry of co-adsorbed methyl moieties and hydrogen atoms.