Internal energy distributions in the CO and CO₂ molecules formed by molecular-beam surface reactions on a polycrystalline Pt foil have been studied by using FT-IR emission spectroscopy. The CO molecules produced by partial oxidation of n-butane or iso-butane at a surface temperature of 1500 K are substantially vibrationally excited (vibrational temperature : Tv=2300 K), but rotationally very cool (rotational temperature : TR=360 K). The low TR value is not due to the rotational relaxation by the gas phase collision. In contrast, the CO molecules produced by CH₃OH decomposition are not vibrationally excited at all. This impliee that the mechanism is different between the partial oxidation of butane and the decomposition of CH₃OH. On the other hand, the CO₂ molecules produced and desorbed by oxidation of CH₃OH is both vibrationally and rotationally excited, but the internal energy distributions of the CO₂ molecules are different from those formed by the, CO+O₂ reaction or the CO+O reaction. These differences in internal energy distributions can provide us with some information on the dynamics (including the structure of the activated complex and the energy transfer processes) of surface catalyzed reactions.