Effect of the nature of iron precursors on the activity of Fe-containing catalysts in CO2 conversion

In this paper the effect of the iron precursors nature (iron (III) nitrate nonahydrate, iron (II) acetate, iron (III) citrate, and ammonium trioxalatoferrate (III)) on alumina-supported catalysts activity in CO2 conversion was studied. The CO2 conversion was carried out at temperatures range from 300 degrees C to 380 degrees C and atmospheric pressure. The structure of the samples was investigated using TPR-H2, SEM-EDX, ICP-AES, XRD, UV-VIS, and XPS methods. It was discovered that depending on the type of Fe precursor the dispersion of the supported iron and the interaction between the deposited component and the carrier in the catalyst can drastically change. During the preparation a mixed phase of iron and aluminum oxides was formed which occurred to be catalytically inactive in CO2 conversion. The formation of this phase prevents the deep reduction of iron and the activation of hydrogen under the reaction conditions, which significantly reduces the activity of the catalyst.