A device and method relating to the storage and delivery of ammonia for use in an after-treatment device for NOx reduction in an exhaust stream, is disclosed. The device includes a cartridge having an ammonia adsorbing and desorbing material contained therein, and a recharging device for use in recharging the material with ammonia after the ammonia is released to a pre-determined level. The method includes providing a sealable cartridge having an interior, providing a predetermined amount of an ammonia-containing material within the interior of the container, positioning a recharging device within the interior of the sealable cartridge, releasing ammonia gas from the ammonia-containing material into an after-treatment device for use in the exhaust system of a vehicle for the reduction of NOx, introducing liquid ammonia into the recharging device, and recharging the ammonia-containing material for re-use in the exhaust system.