IMPROVED ACTIVITY OF FE-CU CATALYSTS BY PHYSICAL MIXING WITH ZEOLITESFOR THE HYDROGENATION OF CARBON-DIOXIDE

The hydrogenation of carbon dioxide was catalyzed at 250 degrees C ove r Fe-Cu/zeolite composite catalysts. Physical mixing of zeolites with Na-rich Fe-Cu Fischer-Tropsch catalysts drastically enhanced the activ ity. Branched and heavier hydrocarbons were obtained over such modifie d composite catalysts. It is proposed that sodium migrated from the su rface of the metal catalyst to the zeolite via the solid-state reactio n. It was illustrated that a solid-state reaction between physically-m ixed catalysts is an attractive route to modification of the zeolites and to the preparation of bifunctional catalysts possessing both acidi c and hydrogenation functions.