Method for the Removal of Nitrogen Oxides from Exhaust Gas by Selective Catalytic Reduction in Presence of an SCR Catalyst Comprising a Fe-AEI Zeolithic Material Essentially Free of Alkali Metal

摘要

A method for the removal of nitrogen oxides from exhaust, flue or off gas by selective catalytic reduction in presence of ammonia as a reductant, comprising the steps of contacting the exhaust gas together with the ammonia or a precursor thereof with an SCR catalyst comprising a Fe-AEI zeolite material essentially free of alkali metal ions (Alk), having the following molar compositions:; SiO₂:o Al₂O₃:p Fe:q Alk;wherein o is in the range from 0.001 to 0.2;wherein p is in the range from 0.001 to 0.2;wherein Alk is one or more of alkali metal ions and wherein q is below 0.02.