A mixed metal oxide, which may be an orthorhombic phase material, is regenerated, selectively enriched or selectively poisoned as a catalyst to reduce catalyst aging for the production of unsaturated carboxylic acids, or unsaturated nitrites, from alkanes, or mixtures of alkanes and alkenes, by contacting said mixed metal oxide with a an oxidizing gas such as oxygen, air, steam and combinations thereof is permitted to flow through the catalyst in a regenerator at a temperature of from 300° C. to 600° C. to form said regenerated catalyst.