【摘要】 采用稀燃富燃交替运行方式,研究存储还原型催化剂Pt/MgO的NOx存储性能以及C3H6 还原NOx反应性能。氧化存储段,NOx可被有效存储;当氧化性气氛转换为还原性气氛后,出现一个NOx峰,降低了总的转化效果。NOx峰的大小与存储段和还原段时间之比、温度等因素有关; 400℃时NOx峰最小,总转化率最高。5h循环实验表明, 400℃时Pt/MgO催化剂再生良好,NOx转化率稳定在96%。于反应气氛中添加100mg/m3 SO2 进行了5h抗硫性实验, Pt/MgO催化剂的抗硫中毒能力明显强于Pt/BaO/Al2O3。更多还原

【Abstract】 A novel NO_x storage-reduction （NSR） catalyst of Pt/MgO was prepared by impregnation. The performances of NO_x storage and reduction by C₃H₆ over Pt/MgO were studied. The NO_x conversion over this catalyst was evaluated with lean-rich cycles at different temperatures. Under lean conditions, Pt/MgO can store NO_x effectively, while a NO_x breakthrough peak emerged when switching from lean conditions to rich conditions. The emergence of the breakthrough peak lowered the total NO_x conversion. The intensity of the NO_x breakthrough peak was relative to the lean-rich cycle spans and temperature can also affect it. This peak reached minimum at 400 ℃, which lead to the best NO_x conversion. The result of 5 h cycle experiment showed that Pt/MgO had a good regenerability at 400 ℃ and the NO_x conversion stablized at 96%. When 100 mg/m3 SO₂ was added to the reaction feed, after five hours, the NO_x conversion over Pt/MgO lowered from 96% to 72%, while the conversion over Pt/BaO/Al₂O₃ diminished from 78% to 18%. This indicates that compared with Pt/BaO/Al₂O₃, Pt/MgO has better resistance to SO₂.更多还原