Adsorption and hydrogenation of CO2 on precipitated iron catalysts: a combined TPD and Moessbauer study

The hydrogenation of CO2 on a precipitated Fe-catalyst and the formation of oxidic and carbidic iron phases were investigated. The hydrogenation reaction was studied by transient- and synthesis-experiments, changes in the structure of the catalyst were followed by X-ray-diffraction and Moessbauer-spectroscopy. In pure CO2 the iron is converted to magnetite. In CO2-H2-mixtures the catalyst is completely converted to cementite. In the initial state of this reaction small amounts of magnetite are formed in the pores of the catalyst. Methane is the main product of the hydrogenation. (orig.)