Systems and methods of removing at least nitrogen oxides from an exhaust fluid generally include dividing a flow of an exhaust fluid comprising a concentration of nitric oxide into three types of flow-through cells. The first flow-through cell comprises a catalyst configured to reduce the nitric oxide with a reductant to form a first feedstream comprising nitrogen containing species derived therefrom. The second flow-through cell comprises a catalyst configured to oxidize nitric oxide to form a second feedstream comprising nitrogen dioxide. The third flow-through cell does not change the nitric oxide concentration and form a third feedstream comprising nitric oxide. After flowing through the three different types of cells, the feedstreams are mixed to form a homogenous mixture and then fed to a catalyst bed configured to convert the nitrogen containing species, the nitric oxide, and the nitrogen dioxide to a fluid comprising nitrogen gas and water.