Selective Catalytic Reduction: Exhaust aftertreatment for reducing nitrogen oxide emissions

The term Selective Catalytic Reduction (or SCR) is used to describe a chemical reaction in which harmful nitrogen oxides (NOX) in exhaust gas are converted into water (H2O) and nitrogen (N2). In combination with internal engine technologies, such as exhaust gas recirculation (EGR), extremely low nitrogen oxide emissions can be achieved with low fuel consumption.