The inhibition by nitrogen of the chemisorption of carbon monoxide on an unpromoted iron catalyst

Abstract

The effect of chemisorbed nitrogen on the adsorption of carbon monoxide at −195 °C was studied on an unpromoted iron catalyst. The results indicate that the adsorption of 1 cm 3 of nitrogen at 300 °C causes a decrease of 0.5 cm 3 in the amount of carbon monoxide adsorbed at −195 °C. The inhibition appears to be greater the lower the temperature at which the nitrogen is chemisorbed, being as high as 0.75 cm 3 when the nitrogen is adsorbed at 200 ° and as low as 0.25 cm 3 when it is adsorbed at 400 °C. The inhibitive effect of chemisorbed nitrogen is greater on the pure iron sample than previously noted for a promoted iron catalyst, though for both promoted and unpromoted iron the chemisorbed nitrogen at a synthesis temperature of 450 °C appears to be primarily in an atomic rather than molecular form on the surface.