HYDROGENATION OF CARBON-DIOXIDE OVER FE-CU-NA ZEOLITE COMPOSITE CATALYSTS - NA MIGRATION VIA SOLID-SOLID REACTION AND ITS EFFECTS ON THE CATALYTIC ACTIVITY/

Composite catalysts containing zeolites and Na-rich Fe-Cu Fischer-Trop sch catalysts were studied for the hydrogenation of carbon dioxide at 250 degrees C. Sodium migration from the surface of the F-T catalyst t o the zeolite via solid-solid reaction seemed to change the acidity of the zeolite and the reduction degree of the Fe catalyst, which findin g was supported by TG and XRD measurements. It was shown that branched and higher hydrocarbons can be obtained in good yields by using compo site catalysts containing iron-based catalysts with moderate alkali co ntent and zeolites with suitable acidity. (C) 1998 Elsevier Science B. V. All rights reserved.