A vehicle and a method of determining a reductant storage capacity set point of a selective catalytic reduction filter (SCRF) of an exhaust treatment system of a vehicle are disclosed. The method includes determining a storage estimate of a reductant inside the SCRF and determining a particulate estimate in the SCRF representative of an amount of particulate matter collected inside the SCRF. The method also includes determining a particulate correction factor from the particulate estimate and calculating, via a controller, a set point value of the reductant in the SCRF by computing together the particulate correction factor and the storage estimate to determine the reductant storage capacity set point of the SCRF.