Hydrocarbon synthesis and carbon dioxide adsorption on iron catalysts

Abstract

Adsorption isotherms have been measured for carbon dioxide on iron synthetic-NH 3 catalyst and on low-grade iron ore at six temperatures in the range 100–350°C and at pressures up to one atmosphere. The results indicate that at least two dissimilar types of adsorbed CO 2 exist on the surface of the iron synthetic-NH 3 catalyst, one of which is generated only at temperatures >250° C. By contrast, only one form of adsorbed CO 2 was detected on the iron ore catalyst at all temperatures up to 350°C. The kinetics of carbon monoxide hydrogenation are comparable over the two catalysts, and both exhibit virtually identical selectivities for methane formation at equivalent total CO conversions.