Investigation of Reaction Mechanism of NO–C₃H₆–CO–O₂ Reaction over\nNiFe₂O₄ Catalyst

Abstract

To elucidate the\nreaction mechanism of NO–C₃H₆–CO–O₂ over NiFe₂O₄, we investigated the dynamics\nof the adsorbed and gaseous\nspecies during the reaction using operando Fourier transform infrared\n(FTIR). The NO reduction activity dependent on the C₃H₆ and CO concentrations suggested that NO is reduced by C₃H₆ under three-way catalytic conditions. From FTIR\nmeasurements and kinetic analysis, it was clarified that the acetate\nspecies reacted with NO–O₂ to form N₂ via NCO, and that the rate-limiting step of NO reduction was the\nreaction between CH₃COO^– and NO–O₂. The NO reduction mechanism of the three-way catalyst on\nNiFe₂O₄ is different to that on platinum-group\nmetal catalysts, on which NO reduction proceeds through N–O\ncleavage.