TITLE: Catalytic Behaviors of Fe-Mn Mixed Oxides.

AUTHOR: M. T. Lee.

INST.  AUTHOR: National Taiwan Univ., Taipei.

SPONSOR: National Science Council, Taipei (Taiwan).

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: Taiwan, Province of China

SOURCE: Other [$TFSTC],  1988,  87p.

NTIS ORDER NO.: PB90-140971INW

ABSTRACT:

The effect of the addition of manganese oxide to an iron catalyst for Fischer-Tropsch reaction was studied by Moessbauer spectroscopy, X-ray diffraction, temperature programmed reduction and kinetic measurements.  Catalysts before reduction are composed of binary oxide solid solutions such as Fe2-xMnxO3 and Mn2-xFexO3 phases. Addition of manganese strongly stabilizes the intermediate oxidation state of catalysts, preventing complete reduction. After the use for CO hydrogenation, catalysts are oxidized as well as carburized and complex phases result. It is believed that Mn(3-y)FeyO4 mixed spinel and Fe(1-Z)Mn(z)O mixed oxide are the most powerful phases for olefin production. The highest attainable 2-4 low carbon olefin selectivity obtained is 41% on a 86% conversion level.  Carbide formation is greatly connected with manganese content and activation procedure used. It is speculated that more unstable carbide is necessary to produce more olefin.