EFFECT OF THE ACTIVATION ATMOSPHERE ON THE ACTIVITY OF Fe CATALYSTS SUPPORTED ON SBA-15 IN THE FISCHER-TROPSCH SYNTHESIS

L.EONARDO A. CANO; MARÍA V. CAGNOLI; JOSÉ F. BENGOA; ANA M. ALVAREZ; SERGIO G. MARCHETTI.

JOURNAL OF CATALYSIS

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2011 vol. 278 p. 310 - 320

0021-9517

An iron catalyst supported on SBA-15 was prepared and activated in H2 stream and in synthesis gas(H2:CO=2:1) stream, in order to be used in the Fischer-Tropsch Synthesis. The different activationtreatments led to different Fe species in fresh catalysts: -Fe, Fe3O4 and Fe2+ diffused into the SBA-15walls in H2-Fe/SBA-15 and -Fe5C2, Fe3O4 and Fe2+ in H2:CO-Fe/SBA -15. These initial differences inthe "bulk" structure of the solids disappear when both catalysts are ?working?. However, a higherproduction of total hydrocarbons, higher CO conversion and more CH4 and light gases were obtained forH2-Fe/SBA-15 over six days. Besides, a higher selectivity towards light olefins was obtained with H2-Fe/SBA-15 during the first 24 h on reaction stream, but this selectivity decreases with the reaction time.These results are explained considering that the iron carbides produced from α-Fe are more active and/orhas smaller sizes than that obtained from α-Fe2O3.