MeOx/Al2O3 and MeOx/CeO2 (Me = Fe, Co, Ni) catalysts for high temperature N2O decomposition and NH3 oxidation

Abstract

A series of MeO_x/Al₂O₃ and MeO_x/CeO₂ (Me = Fe, Co, Ni) compounds was prepared by incipient wetness impregnation and characterized by XRD, XPS, UV-vis DRS, differential dissolution phase analysis (DDPA). Their activity towards N₂O decomposition and ammonia oxidation at 750–900 °C was shown to depend on oxygen mobility in the sample as characterized by steady state isotopic transient kinetic analysis (¹⁸O SSITKA) and dispersion of MeO_x (Me = Fe) species. Obvious reverse “activity-FeO_x dispersion” dependence was related to the change of contribution from oxygen transfer from the support to active sites through the Me–ceria or not improbably, the Me–alumina interface. It was shown that the high efficiency of CeO₂ based samples in deN₂O can be additionally increased by CeO₂ supporting onto high surface area alumina.