NOx Molecule Adsorption in [Ag]-MAPO-5 (M=Si, Ti) Molecular Sieves

NOx adsorption in silver. exchanged aluminophosphate molecular sieves ([Ag]-SAPO-5 and [Ag]-TAPO-5) was investigated using the density functional theory (DFT). Equilibrium structure parameters and adsorption energies were obtained and compared. The results indicated that the eta N1- mode was more stable than the eta(1)-O mode. The adsorption energy values of NOx followed the order: NO2>NO>N2O. Compared to the free gas state, the bond parameters of NO and NO2 in the adsorbed state changed more than that of N2O in [Ag]-SAPO-5 and [Ag]-TAPO-5. Moreover, [Ag]-SAPO-5 and [Ag]-TAPO-5 had a higher activation for the NOx molecule compared to [Ag]-AlMOR. The resistance capabilities of [Ag]-SAPO-5 and [Ag]-TAPO-5 to SO2, H2O, and O-2 were also studied and analyzed. In addition, the interaction mechanism of NOx in silver. exchanged aluminophosphate molecular sieves was investigated using natural bond orbital (NBO) analysis.