Abstract: The invention relates to a process of the oxidative dehydrogenation of an alkane containing 2 to 6 carbon atoms and/or the oxidation of an alkene containing 2 to 6 carbon atoms, comprising contacting a first gas stream comprising oxygen and the alkane containing 2 to 6 carbon atoms and/or the alkene containing 2 to 6 carbon atoms with a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium; followed by contacting a second gas stream comprising methane, an inert gas or oxygen or any combination of two or more of these with the catalyst, wherein the second gas stream comprises 0 to 25 vol. % of the alkane containing 2 to 6 carbon atoms and/or alkene containing 2 to 6 carbon atoms.