A vehicle system having an internal combustion engine and evaporative emission system including a canister is described, wherein canister includes a chamber having a flexible Metal Organic Framework (MOF) material disposed therein. A controllable device is coupled to the flexible MOF material, and a controller is operatively connected to the controllable device and the purge valve. The controller includes an instruction set that is executable to activate the controllable device and control the purge valve to an open state in response to a command to purge the canister, determine an activation parameter for the controllable device, determine a purge flow, integrate the purge flow to determine a total purge mass, and deactivate the controllable device when the total purge mass is greater than a threshold.