Structure and redox properties of bulk and supported manganese oxide catalysts

Abstract

The effects of the oxide carrier (γ-Al2O3, SiO2, ZrO2, TiO2), MnOx precursor (KMnO4 , Mn(NO3)2 and Mn(CH3COO)2), loading (2–17 wt.% Mn) and preparation method on the structure and reduction pattern of MnOx-based catalysts have been systematically evaluated by X-ray diffraction (XRD) and temperature programmed reduction (TPR) measurements in the range 273–1073 K. Oxide precursor and preparation method determine both the structure and average oxidation number (A.O.N.) of the MnOx (1.5<x<2) phase in bulk and supported systems. The reducibility scale, based on the inverse sequence of the onset temperature of reduction (To,red),