The time- and temperature-dependent adsorption on N₂O, CO, and CH₄ on CVD-grown graphene has been investigated by MIR reflection−absorption spectroscopy to gain information about the adsorption kinetics, notably the rate constants k and activation energies E_a on the adsorption step. The gas adsorption is followed by determining the change of the reflected beam intensity with time by taking difference spectra, i.e., subtracting the baseline signal (reflectivity of graphene at the respective gas excitation line) from the measurement with added gas. The experiments yield adsorption activation energies E_a of −19.6 ± 1.1 (N₂O), −12.1 ± 0.2 (CO), and −9.5 ± 1.7 kJ/mol (CH₄). The obtained E_a values are in excellent agreement with the literature results from theory, thereby confrming these studies. The E_a values indicate physisorption, i.e., no strong bonding of the gas molecules to graphene. The analyzed adsorption rate constants k are reported for the frst time and are on the order of 10¹¹ to 10¹² molecules·s⁻¹·cm⁻² with N₂O showing the highest value and CH₄ the lowest value. The adsorption rate constants follow the series N₂O > CO > CH₄, in line with the charge transfer abilities of the molecules. This work can be easily extended to kinetic studies of other gases hazardous to the environment and adsorption studies with other 2D materials using versatile MIR reflection−absorption spectroscopy.