The sorption of CO and CO2 on dehydroxylated gamma Al2O3 was studied by means of temperature programmed desorption (TPD) and single pulse experiments in a TAP reactor. The peak temperatures in the TPD responses of CO and CO2 shift to higher values with lower initial surface coverage. The TPD responses have a tail at higher temperatures. Both observations result from a broad distribution of the heat of adsorption of CO and CO2 on gamma Al2O3. Simulation and regression of the pulse responses of CO and CO2 involved a Temkin distribution of the activation energy of desorption. The lower boundary of the activation energy for desorption of both CO and CO2 is 100 kJ/mol. The width of the distributions of the activation energy of desorption of CO and CO2 are, respectively, 5 and 15 kJ/mol.