V-ZSM-5上氨选择性催化还原NO降解机理的DFT研究

Theoretical study of V-ZSM-5 for the selective catalytic reduction of nitrogen oxides with ammonia by DFT

运用密度泛函理论对NO在V-ZSM-5的周期性晶包模型上的氨选择性催化还原降解路径进行了系统的研究。计算结果表明,NO优先于NH_3吸附于V上,NO的氨选择性催化还原降解反应经过生成不稳定的中间产物NH_2NO,随着中间产物NH_2NO分解成H_2O和N2,NO被分解。不稳定的中间产物NH_2NO在[VO]1+活性位点上也可以分解成H_2O和N_2。

Density functional theory calculations were carried out to investigate the reaction mechanism of selective catalytic reduction of nitrogen oxides by ammonia over V-ZSM-5periodic unit cell model.The computational results show that NO is prefer to absorb on V than NH3.The NH3 molecule selectively interacts with NO molecule to form NH2 NO intermediate and then NH2 NO decomposes to H2O and N2.We also found that NH2 NO can decomposes to H2O and N2over[VO]1＋active site.