HYDROGENATION OF CARBON-DIOXIDE OVER ALUMINA-SUPPORTED FE-K CATALYSTS

The hydrogenation of CO2 has been studied over Fe/alumina and Fe-K/alu mina catalysts. The addition of potassium increases the chemisorption ability of CO2 but decreases that of Hz. The catalytic activity test a t high pressure (20 atm) reveals that remarkably high activity and sel ectivity toward light olefins and C-2+ hydrocarbons can be achieved wi th Fe-K/alumina catalysts containing high concentration of K (K/Fe mol ar ratio = 0.5, 1.0). In the reaction at atmospheric pressure, the hig hly K-promoted catalysts give much higher CO formation rate than the u npromoted catalyst. It is deduced that the remarkable catalytic proper ties in the presence of K are attributable to the increase in the abil ity of CO2 chemisorption and the enhanced activity for CO formation, w hich is the preceding step of C-2+ hydrocarbon formation.