fig2

Figure 2. (A) NH₃-SCR curves of Cu-SSZ-13 and Cu&Zn-SSZ-13 zeolites; (B) DFT calculated reaction Gibbs free energies (ΔG) for different active centers; (C) ΔG values of active centers at different temperatures. Reproduced with permission from^[87]. Copyright 2020, American Chemical Society; (D) NH₃-SCR curves of Cu-SSZ-13 and Cu-Sm-SSZ-13 zeolites; (E) ΔG profiles for replacement of [Z₂Sm³⁺(OH)]²⁺ ion at 6MR by Cu²⁺ ion; (F) ΔG profiles for replacement of Z₂Cu²⁺ ion at 6MR by Sm³⁺ ion. Reproduced with permission from^[65]. Copyright 2022, American Chemical Society. NH₃-SCR: Ammonia-assisted selective catalytic reduction; DFT: density functional theory; 6MR: six-membered ring.