Methods and systems for extending the life of a dehydrogenation catalyst are described herein. For example, one embodiment includes providing a reaction vessel loaded with a dehydrogenation catalyst with a feedstream via a conduit in operable communication with the reaction vessel. The feedstream may include an alkyl aromatic hydrocarbon and the dehydrogenation catalyst may be adapted to convert the alkyl aromatic hydrocarbon to a vinyl aromatic hydrocarbon. The feedstream may be contacted with an aqueous catalyst life extender, wherein the aqueous catalyst life extender enters the conduit at a linear velocity sufficient to prevent vaporization of the catalyst life extender in the conduit prior to contact with the feedstream.