查看文章

We here report a mechanistic investigation into the electrochemical transport of CO 2 through a dense metal-carbonate membrane. The investigation studied a total of six possible charge-transfer mechanisms involving CO 3 2−, O 2 2−, O 2−, CO 4 2− and CO 5 2− as the active surface species, and derived the corresponding flux equation from each mechanism. The experimental CO 2 flux densities measured under a range of chemical gradients were used to verify each mechanism by plotting the flux density against the corresponding flux expression of each mechanism. The results showed that CO 4 2− scheme is the best mechanism to describe the electrochemical CO 2 transport through the metal-carbonate membranes. A new transport model was also shown to describe the CO 4 2− migration and charge-transfer.