Application of Mössbauer Spectroscopy to the Carbon Oxides Hydrogenation Reactions

Abstract:

Iron-based catalysts have favorable activity and selectivity properties for the CO and CO<inf>2</inf> hydrogenation reactions. Several Fe phases (oxides and carbides) can be present in these catalysts. The interaction of Fe with the other components of the catalyst (support, promoters) can affect the ease of reduction and also its transformation during the reactions. In this work, the relationship between catalytic behavior in the CO and CO<inf>2</inf> hydrogenation reactions and the Fe phase composition of fresh and reacted catalysts was studied. Two types of catalysts were tested: a laterite and the other one made of iron supported on alumina, both unpromoted and promoted with K and Mn. Only those Fe species which can be reduced-carburized, by means of a pretreatment or by an in situ transformation under the reaction, seem to be able to perform the CO or CO<inf>2</inf> hydrogenation. The reoxidation of the Fe carbide to magnetite was not associated to deactivation. The selectivity seems to be more affected by Fe species difficult to reduce than by magnetite produced by reoxidation.

Año de publicación:

2001

Keywords:

• Fischer–Tropsch synthesis
• C&lt;inf&gt;2&lt;/inf&gt;–C&lt;inf&gt;4&lt;/inf&gt; hydrocarbons
• carbon dioxide hydrogenation
• iron carbides

Fuente:

scopus