In the Li-SAPO-RHO series, the adsorption of C2H4 and C2H6 was significantly influenced by the Li + content, controlled by varying the number of exchange cycles (table ). Higher Li + content reduced the adsorption capacity for both gases. Notably, when the Li + content was below 3.2 ions per unit cell (e.g., Li-2-SAPO-RHO), the reduction in C2H6 uptake was more significant than for C2H4 (Fig. ). However, this trend reversed when Li + content exceeded 3.2 ions per unit cell.