Density Functional Theory Study on the Effect of Isomorphic Substitution of FAU Molecular Sieve on N₂ Adsorption Performance

Figure 4

Structure models and charge difference density diagrams of N₂ adsorption at three kinds of doped β-cages that are optimized as the best adsorption sites: (a, g) Zn replaces Al (Al), (b, h) Zn replaces Al (Si), (c, i) Ca replaces Al (Al′), (d, j) Ga replaces Si (Al′), (e, k) Ga replaces Si (Si), and (f, l) Ga replaces Si (Si′). The average valence charge of the Si site after N₂ adsorption is shown in the figure; the isosurface value is 0.002 e Bohr⁻³.

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