The Mechanism of Low-Temperature Ammonia Oxidation on Metal Oxides According to the Data of Spectrokinetic Measurements

Low temperature ammonia oxidation on MoO₃, Fe₂O₃, Cr₂O₃, and ZnO is studied by the spectrokinetic method. It is shown that the following adsorbed species are intermediates in this reaction: NH₃ and N₂O on Fe₂O₃ and ZnO; NH₃, N₂O, and NO on Cr₂O₃. All of the detected intermediates are used to construct the mechanism of the process. In the framework of the proposed mechanism, stationary and nonstationary spectral and kinetic data are quantitatively processed. The dependence of the rate constants of the same steps on different oxides on their physicochemical properties is discussed.