Reaction mechanism of methanol decomposition on Pt-based model catalysts: a theoretical study.

The decomposition mechanisms of methanol on five different Pt surfaces, the flat surface of Pt(111), Pt-defect, Pt-step, Pt(110)(1 x 1), and Pt(110)(2 x 1), have been studied with the DFT-GGA method using the repeated slab model. The adsorption energies under the most stable configuration of the possible species and the activation energy barriers of the possible elementary reactions involved are obtained in this work. Through systematic calculations for the reaction mechanism of methanol decomposition on these surfaces, we found that such a reaction shows the same reaction mechanism on these Pt-based model catalysts, that is, the final products are all H (H(ads)) and CO (CO(ads)) via O-H bond breaking in methanol and C-H bond scission in methoxy. These results are in general agreement with the previous experimental observations.