Investigation of Reaction Mechanism of NO–C3H6–CO–O2 Reaction over NiFe2O4 Catalyst

To elucidate the reaction mechanism of NO-C 3 H 6 -CO-O 2 over NiFe 2 O 4 , we investigated the dynamics of the adsorbed and gaseous species during the reaction using operando Fourier transform infrared (FTIR). The NO reduction activity dependent on the C 3 H 6 and CO concentrations suggested that NO is reduced by C 3 H 6 under three-way catalytic conditions. From FTIR measurements and kinetic analysis, it was clarified that the acetate species reacted with NO-O 2 to form N 2 via NCO, and that the rate-limiting step of NO reduction was the reaction between CH 3 COO - and NO-O 2 . The NO reduction mechanism of the three-way catalyst on NiFe 2 O 4 is different to that on platinum-group metal catalysts, on which NO reduction proceeds through N-O cleavage.