To optimize fuel cells performance using alcohols as fuel it is essential to untangle the mechanism of the methanol electro-oxidation on platinum in aqueous medium as a model reaction. Recent studies have pointed out the particular necessity of adsorbed OH for this electro-oxidation process to take place1. The here reported results, carefully obtained under low methanol concentrations on the three basal planes of platinum at different scan rates to discriminate between oxidation and adsorption processes, confirm such an unforeseen preceding observation2. It is elucidated that only when adsorbed OH is already present on the surface, adsorbed CO from methanol is formed. This observation is a clear indication that adsorbed OH is involved in the mechanism beyond providing the oxygen group required to oxidize adsorbed CO, which has never been considered before. The role played by adsorbed OH in the methanol electro-oxidation to CO on platinum in aqueous medium is supported by DFT calculations, as well as the reason why this reaction is not observed in the absence of adsorbed OH. A combination of kinetic and thermodynamic factors, such as the presence of multiple water molecules per methanol molecule, the high adsorbed OH mobility on the surface, the favorable co-adsorption of methanol in the presence of adsorbed OH, and the favorable and virtually barrier-less hydrogen transference from the hydroxy group of methanol to adsorbed OH to yield water, result in the immediate activation of methanol (as soon as the molecule approaches the surface) through the favorable substitution of adsorbed OH by adsorbed methoxy. In this contribution it will be presented a change of paradigm in the understanding of how alcohols are electro-oxidized in reference systems thus having crucial implications in the search for better electrocatalysts.