An exhaust treatment system is provided. Method of increasing activation of NOx reduction catalyst using two or more reductant is discussed. The exhaust treatment system includes an exhaust source, a reductant source, a nitrogen oxide (NOx) reduction catalyst, a sensor, and a controller. The reductant source includes a first reductant and second reductant, and is disposed to inject a reductant stream into an exhaust stream from the exhaust source. The NOx catalyst is disposed to receive both the exhaust stream and reductant stream. The sensor is disposed to sense a system parameter related to carbon loading of the catalyst and produce a signal corresponding to the system parameter. The controller is disposed to receive the signal and to control dosing of the reductant stream based at least in part on the signal.