A new material for combustion exhaust aftertreatment at low temperature

Materials which catalyse the reduction of gas phase nitrogen oxides (NOx), from combustion devices such as diesel engines, are needed to meet emissions regulations and improve air quality. Here we use flow tube engine laboratory systems investigate an iron silicate material (LowCat) catalyses CO oxidation NOx simultaneously is effective at low temperatures. LowCat’s potential for mitigation was assessed by combining quantitative kinetics with understanding its mechanism action. Annealing LowCat transforms a goethite component hematite, increasing catalytic activity. A surface bound O intermediate, critical binding NH3 reductant, forms facilitates NO2 room temperature. This intermediate can also be formed O2 NO above 450 K. mechanistic allowed assessment performance. The catalyst shows significant activity under conditions relevant automotive other has particular advantage reducing N2 temperatures below 150 °C. represents exciting opportunity create Selective Catalytic Reduction (SCR) exhaust aftertreatment superior temperature performance, load operation diesel-powered vehicles that often important contributors urban