SURFACE COORDINATE GEOMETRY OF IRON CATALYSTS - HYDROGENATION OF CO2 OVER FE ZRO2 PREPARED BY A NOVEL METHOD/

Zirconia-supported iron oxide catalyst has been designed following the approach to the Fe/TiO2 catalyst. The catalyst prepared by reducing t he precursor obtained from incipient wetness impregnation in H-2 at th e proper temperature exhibits good activity (CO2 conversion > 20%) and selectivity (68%) in the selective synthesis of hydrocarbons (C-2-C-5 ) from CO2 and H-2 The catalytic activity has been found to vary with iron weight loadings in a ''two maxima'' fashion and is also affected by reduction temperature. Mossbauer and EXAFS analyses suggest that th e active phases are coordinatively unsaturated ferric cations and alph a-Fe. No ferrous cations are observed. A good geometric arrangement fo r the two phases on the catalyst is thought to give the highest cataly tic activity.