Pathways for methanol steam reforming involving adsorbed formaldehyde and hydroxyl intermediates on Cu(111): density functional theory studies

Plane-wave density functional theory calculations have been carried out to explore possible pathways in methanol steam reforming (MSR) on Cu(111). We focus on reactions involving the adsorbed formaldehyde intermediate (CH(2)O) produced by methanol decomposition and the surface hydroxyl (OH) species generated by dissociative adsorption of H(2)O. Several possible pathways leading to the H(2) + CO(2) products have been identified. The two most likely pathways involve the formate (CHOO), rather than the carboxyl (COOH), intermediate, and they possess barriers lower than that of the rate-limiting step of MSR, namely the dehydrogenation of adsorbed methoxyl (CH(3)O) species.