Figure 8.

(a) Coordination of the Na⁺ cation and corresponding CO adsorption complex in a single cation site of Na-FER. Framework Al, Si and O atoms are depicted in black, grey and red colors, respectively; Na⁺, C and O atoms of CO are shown as violet, grey and red balls, respectively. The distances between Na⁺ and the nearest framework O atoms are given in Å; (b) CO adsorption complex on a dual cation site in Na-FER. The CO molecule interacts with the primary Na⁺ cation (violet ball) through the C atom (grey ball) and with the secondary Na⁺ cation (yellow ball) through the O atom (red ball). For further details, see [44].