The infrared chemiluminescence technique was applied to catalytic oxidation of CH
3OH, HCOOH and i-C
4H
10 on a Pd surface, and the reaction dynamics and mechanism were discussed in terms of internal energy states of nascent product CO
2 and CO molecules. The vibrational and rotational states of CO
2 produced by CH
3OH oxidation were quite similar to those of CO
2 produced by CO oxidation, indicating that the final step of the CO
2 formation in the CH
3OH oxidation involved a bimolecular process (i.e., CO
ad+O
ad). On the contrary, the intensity of IR emission of CO
2 produced by HCOOH oxidation was very weak, suggesting that most of CO
2 was not so vibrationally excited and that CO
2 was formed via decomposition of HCOO
ad (unimolecular decomposition of formate). The selective production of CO and H
2O was observed by the partial oxidation of i-C
4H
10 on Pd, and the vibrational state of product CO was very different between the Pd and Pt surfaces. These differences in internal energy states of the CO and CO
2 products can provide us with new information on the dynamics and mechanism of catalytic reactions.
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