A dual-bed fixed-bed reactor consisting of a selective catalytic reduction (SCR) catalyst and a lean NOx trap (LNT) catalyst is designed and employed for high-concentration NOx removal under lean-burn condition. The lean NOx could be partially reduced over the upstream SCR catalyst (Cu/Al₂O₃) by C₃H₆ in the stream, greatly increasing the efficiencies of both NOx storage and NOx reduction over the downstream LNT catalyst (La_0.7Sr_0.3CoO₃). The activity tests for individual catalyst show that the Cu/Al₂O₃ containing 5 wt.% Cu is the optimal SCR catalyst, which exhibits similar temperature window of activity (300–350 °C) as the LNT catalyst La_0.7Sr_0.3CoO₃. The relative ratio of CuO nanoparticles to surface CuAl₂O₄ spinel on Cu/Al₂O₃ is rather important for NO-SCR due to the requirements of appropriate oxidation ability of SCR catalysts. As compared with the single SCR or LNT catalyst, the dual-bed SCR-LNT coupled system shows much lower NOx leak in both lean- and rich-burn periods, especially under the condition of high NOx concentration and high space velocity. Additionally, the NOx to N₂O selectivity over this coupled system is as low as ∼4%, showing obvious advantage over conventional noble metals-based SCR and LNT catalysts.

设计了由选择性催化还原（SCR）催化剂和稀薄NOx捕集器（LNT）催化剂组成的双层固定床反应器，并将其用于稀薄燃烧条件下的高浓度NOx去除。流中的C ₃ H ₆可以使上游SCR催化剂（Cu / Al ₂ O ₃）上的贫NOx部分还原，大大提高了下游LNT催化剂（La _0.7 Sr _0.3）的NOx储存效率和NOx还原效率CoO ₃）。单个催化剂的活性测试表明，Cu / Al ₂ O ₃包含5 wt。％Cu的是最佳的SCR催化剂，与LNT催化剂La _0.7 Sr _0.3 CoO ₃表现出相似的温度范围（300-350°C）。由于SCR催化剂具有适当的氧化能力的要求，对于NO-SCR ，CuO纳米颗粒与Cu / Al ₂ O ₃表面上的CuAl ₂ O ₄尖晶石的相对比例非常重要。与单SCR或LNT催化剂相比，双床SCR-LNT耦合系统在稀燃和浓燃期间均显示出低得多的NOx泄漏，特别是在高NOx浓度和高空速的条件下。另外，NOx转化为N ₂在该偶联体系上的O选择性低至约4％，显示出优于常规的基于贵金属的SCR和LNT催化剂的明显优势。