For the first time the possibility to partially oxidize methane to methanol and formaldehyde at low temperature over Co-ZSM-5 using air is shown. The influence of the preparation method on the nature of the cobalt species is investigated. In addition, the catalytic activity and selectivity for methane oxidation as a function of the cobalt speciation is discussed. Based on UV-vis-NIR and FT-IR spectroscopy, H-2-TPR, TEM and kinetic measurements it is concluded that cobalt in ion-exchange positions results mainly in the formation of formaldehyde, while larger Co-oxide particles prepared by impregnation result in the formation of methanol.