Methanol decomposition on low index and stepped CeO2 surfaces from GGA+U

•Methanol adsorption is exothermic on oxidized as well as on the partially reduced surfaces.•The first dehydrogenation by breaking the CH methyl bond is very unlikely.•The reaction from methanol to metoxy is hightly probable for all surfaces.•Stepped surfaces are the most reactive for the decomposition of methanol.•Methoxy to formaldehide is the rate-determining step on the most reactive surfaces.