The steady-state reaction of CO2-H2 mixtures with liquid copper at 1423 K

Abstract

Measurements have been made of the steady-state oxygen activity in liquid copper at 1423 K in flowing CO2-H2 gas mixtures. For CO2/H2 ratios varying between 0.25 and 6.0, it is found that the steady-state oxygen activity, expressed aspO 2, is 1 to 2 orders of magnitude below that consistent with complete water-gas equilibrium. The results are interpreted in terms of the consecutive reactions CO2(g) → O(ad) + CO(g) and H2(g) + O(ad) → H2O(g) as the rate determining steps. Consistency of the results with recent surface tension studies of Cu-O alloys is found. The study indicates that the rate of dissociation of H2O(g) is approximately 2 1/2 times higher than the rate of dissociation of CO2 at the bare copper surface at 1423 K.